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  • 1.
    Aarnio, Mikko
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Anaesthesiology and Intensive Care.
    Visualization of Peripheral Pain Generating Processes and Inflammation in Musculoskeletal Tissue using [11C]-D-deprenyl PET2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    An objective visualization and quantification of pain-generating processes in the periphery would alter pain diagnosis and represent an important paradigm shift in pain research. Positron emission tomography (PET) radioligand [11C]-D-deprenyl has shown an elevated uptake in painful inflammatory arthritis and whiplash-associated disorder. However, D-Deprenyl’s molecular binding target and uptake mechanism in inflammation and musculoskeletal injuries are still unknown. The present thesis aimed to gain insight into the mechanisms of D-deprenyl binding and uptake and to verify whether pain-associated sites and inflammation in acute musculoskeletal injury could be visualized, objectively quantified and followed over time with [11C]-D-deprenyl PET-computed tomography (PET/CT).

    To identify the D-deprenyl binding target, a high-throughput analysis and competitive radioligand binding studies were performed. D-deprenyl inhibited monoamine oxidase A (MAO-A) activity by 55%, MAO-B activity by 99% and angiotensin-converting enzyme (ACE) by 70%, which identified these enzymes as higher-affinity targets. Furthermore, radioligand receptor binding assays pointed favorably towards the concept of MAO-B as the primary target. To investigate the biochemical characteristics of the binding site, we used radioligand binding assays to assess differences in the binding profile in inflamed human synovial membranes exhibiting varying levels of inflammation. D-deprenyl bound to a single, saturable population of membrane-bound protein in synovial membrane homogenates and the level of inflammation correlated with an increase in D-deprenyl binding affinity.

    To verify whether D-deprenyl can visualize pain-generating processes, patients with musculoskeletal injuries were investigated and followed-up with [11C]-D-deprenyl PET/CT. In the study of eight patients with ankle sprain, the molecular aspects of inflammation and tissue injury could be visualized, objectively quantified and followed over time with [11C]-D-deprenyl PET/CT. The pain coexisted with increased [11C]-D-deprenyl uptake. In the study of 16 whiplash patients, an altered [11C]-D-deprenyl uptake in the cervical bone structures and facet joints was associated with subjective pain levels and self-rated disability.

    To further evaluate D-Deprenyl’s usefulness as a marker of inflammation, three PET tracers were compared in an animal PET/CT study. Preliminary findings showed that [11C]-D-deprenyl had an almost identical uptake pattern when compared with [11C]-L-deprenyl. The two deprenyl enantiomers showed no signs of specific binding or trapping and therefore may not be useful to study further in models of inflammatory pain, surgical pain, or both.

    This thesis demonstrates that D-deprenyl visualizes painful inflammation in musculoskeletal injuries and that the probable underlying mechanism of [11C]-D-deprenyl uptake is binding to MAO.

    List of papers
    1. High-throughput screening and radioligand binding studies reveal monoamine oxidase-B as the primary binding target for D-deprenyl
    Open this publication in new window or tab >>High-throughput screening and radioligand binding studies reveal monoamine oxidase-B as the primary binding target for D-deprenyl
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    2016 (English)In: Life Sciences, ISSN 0024-3205, E-ISSN 1879-0631, Vol. 152, p. 231-237Article in journal (Refereed) Published
    Abstract [en]

    Aims: D-deprenyl is a useful positron emission tomography tracer for visualization of inflammatory processes. Studies with [C-11]-D-deprenyl showed robust uptake in peripheral painful sites of patients with rheumatoid arthritis or chronic whiplash injury. The mechanism of preferential D-deprenyl uptake is not yet known, but the existence of a specific binding site was proposed. Thus, in the present study, we sought to identify the binding site for D-deprenyl and verify the hypothesis about the possibility of monoamine oxidase enzymes as major targets for this molecule. Main methods: A high-throughput analysis of D-deprenyl activity towards 165 G-protein coupled receptors and 84 enzyme targets was performed. Additionally, binding studies were used to verify the competition of [H-3]D-deprenyl with ligands specific for targets identified in the high-throughput screen. Key findings: Our high-throughput investigation identified monoamine oxidase-B, monoamine oxidase-A and angiotensin converting enzyme as potential targets for D-deprenyl. Further competitive [3H] D-deprenyl binding studies with specific inhibitors identified monoamine oxidase-B as the major binding site. No evident high-affinity hits were identified among G-protein coupled receptors. Significance: Our study was the first to utilize a high-throughput screening approach to identify putative D-deprenyl targets. It verified 249 candidate proteins and confirmed the role of monoamine oxidase - B in D-deprenyl binding. Our results add knowledge about the possible mechanism of D-deprenyl binding, which might aid in explaining the increased uptake of this compound in peripheral inflammation. Monoamine oxidase-B will be further investigated in future studies utilizing human inflamed synovium.

    Keywords
    D-deprenyl High-throughput screening Binding site
    National Category
    Pharmaceutical Sciences Clinical Medicine
    Identifiers
    urn:nbn:se:uu:diva-291492 (URN)10.1016/j.lfs.2016.03.058 (DOI)000375728500028 ()27058977 (PubMedID)
    Funder
    Berzelii Centre EXSELENT, 2013-01495
    Available from: 2016-05-03 Created: 2016-05-03 Last updated: 2018-04-09Bibliographically approved
    2. Characterization of the binding site for d-deprenyl in human inflamed synovial membrane.
    Open this publication in new window or tab >>Characterization of the binding site for d-deprenyl in human inflamed synovial membrane.
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    2018 (English)In: Life Sciences, ISSN 0024-3205, E-ISSN 1879-0631, Vol. 194, p. 26-33Article in journal (Refereed) Published
    Abstract [en]

    Aims: D-Deprenyl when used as a positron emission tomography tracer visualizes peripheral inflammation. The major aim of the current study was to identify and investigate the properties of the binding target for D-deprenyl in synovial membrane explants from arthritic patients.

    Main methods: Thirty patients diagnosed with arthritis or osteoarthritis were enrolled into the study. Homologous and competitive radioligand binding assays utilizing [H-3]D-deprenyl were performed to investigate the biochemical characteristics of the binding site and assess differences in the binding profile in synovial membranes exhibiting varying levels of inflammation.

    Key findings: The [H-3]D-deprenyl binding assay confirmed the existence of a single, saturable population of membrane-bound protein binding sites in synovial membrane homogenates. The macroscopically determined level of inflammation correlated with an increase in [H-3]D-deprenyl binding affinity, without significant alterations in binding site density. Selective monoamine oxidase B inhibitor, selegiline competed for the same site as [H-3]D-deprenyl, but failed to differentiate the samples with regard to their inflammation grade. A monoamine oxidase A inhibitor, pirlindole mesylate showed only weak displacement of [H-3]D-deprenyl binding. No significant alterations in monoamine oxidase B expression was detected, thus it was not confirmed whether it could serve as a marker for ongoing inflammation.

    Significance: Our study was the first to show the biochemical characteristics of the [H-3]D-deprenyl binding site in inflamed human synovium. We confirmed that d-deprenyl could differentiate between patients with varying severity of synovitis in the knee joint by binding to a protein target distinct from monoamine oxidase B.

    Keywords
    Arthritis, Binding target, Monoamine oxidase B, Synovium, d-Deprenyl
    National Category
    Pharmaceutical Sciences
    Research subject
    Pharmaceutical Biochemistry; Medical Biochemistry
    Identifiers
    urn:nbn:se:uu:diva-347601 (URN)10.1016/j.lfs.2017.12.003 (DOI)000425052000004 ()29221756 (PubMedID)
    Funder
    Swedish Research Council, 9459
    Available from: 2018-04-04 Created: 2018-04-04 Last updated: 2018-04-18Bibliographically approved
    3. Visualization of painful inflammation in patients with pain after traumatic ankle sprain using [(11)C]-D-deprenyl PET/CT.
    Open this publication in new window or tab >>Visualization of painful inflammation in patients with pain after traumatic ankle sprain using [(11)C]-D-deprenyl PET/CT.
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    2017 (English)In: Scandinavian Journal of Pain, ISSN 1877-8860, E-ISSN 1877-8879, Vol. 17, no 1, p. 418-424Article in journal (Refereed) Published
    Abstract [en]

    BACKGROUND AND AIMS: Positron emission tomography (PET) with the radioligand [(11)C]-D-deprenyl has shown increased signal at location of pain in patients with rheumatoid arthritis and chronic whiplash injury. The binding site of [(11)C]-D-deprenyl in peripheral tissues is suggested to be mitochondrial monoamine oxidase in cells engaged in post-traumatic inflammation and tissue repair processes. The association between [(11)C]-D-deprenyl uptake and the transition from acute to chronic pain remain unknown. Further imaging studies of musculoskeletal pain at the molecular level would benefit from establishing a clinical model in a common and well-defined injury in otherwise healthy and drug-naïve subjects. The aim of this study was to investigate if [(11)C]-D-deprenyl uptake would be acutely elevated in unilateral ankle sprain and if tracer uptake would be reduced as a function of healing, and correlated with pain localizations and pain experience.

    METHODS: Eight otherwise healthy patients with unilateral ankle sprain were recruited at the emergency department. All underwent [(11)C]-D-deprenyl PET/CT in the acute phase, at one month and 6-14 months after injury.

    RESULTS: Acute [(11)C]-D-deprenyl uptake at the injury site was a factor of 10.7 (range 2.9-37.3) higher than the intact ankle. During healing, [(11)C]-D-deprenyl uptake decreased, but did not normalize until after 11 months. Patients experiencing persistent pain had prolonged [(11)C]-D-deprenyl uptake in painful locations.

    CONCLUSIONS AND IMPLICATIONS: The data provide further support that [(11)C]-D-deprenyl PET can visualize, quantify and follow processes in peripheral tissue that may relate to soft tissue injuries, inflammation and associated nociceptive signaling. Such an objective correlate would represent a progress in pain research, as well as in clinical pain diagnostics and management.

    Place, publisher, year, edition, pages
    Walter de Gruyter, 2017
    Keywords
    Ankle injuries, Carbon-11, Deprenyl, Inflammation, PET, Pain
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-333782 (URN)10.1016/j.sjpain.2017.10.008 (DOI)000419851500070 ()29126847 (PubMedID)
    Available from: 2017-11-16 Created: 2017-11-16 Last updated: 2019-09-25Bibliographically approved
    4. Whiplash injuries associated with experienced pain and disability can be visualized with [11C]-D-deprenyl PET/CT
    Open this publication in new window or tab >>Whiplash injuries associated with experienced pain and disability can be visualized with [11C]-D-deprenyl PET/CT
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    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    The understanding of etiological mechanisms of whiplash associated disorder is still inadequate. Objective visualization and quantification of peripheral musculoskeletal injury and possible painful inflammation in whiplash associated disorder would facilitate diagnosis, strengthen patients’ subjective pain reports and aid clinical decisions eventually leading to better treatments. In the current study, we further evaluated the potential to use [11C]D-deprenyl PET/CT to visualize inflammation after whiplash injury. Sixteen patients with whiplash injury grade II were recruited at the emergency department and underwent [11C]D-deprenyl PET/CT in the acute phase and at 6 months after injury. Subjective pain levels, self rated neck disability and active cervical range of motion were recorded at each imaging session. Results showed that the molecular aspects of inflammation and possible tissue injuries after acute whiplash injury could be visualized, objectively quantified and followed over time with [11C]-D-deprenyl PET/CT. An altered [11C]D-deprenyl uptake in the cervical bone structures and facet joints was associated with subjective pain levels and self rated disability during both imaging occasions. These findings may contribute to a better understanding of affected peripheral structures in whiplash injury and strengthens the idea that PET/CT detectable organic lesions in peripheral tissue may be relevant for the development of persistent pain and disability in whiplash injury.

    Perspective: This article presents a novel way of objectively visualizing possible structural damage and inflammation that cause pain and disability in whiplash injury. This PET method can bring an advance in pain research and eventually would facilitate the clinical management of patients in pain.

    Keywords
    Whiplash; deprenyl; inflammation; pain; PET; carbon-11
    National Category
    Medical and Health Sciences
    Research subject
    Molecular Medicine; Medical Cell Biology
    Identifiers
    urn:nbn:se:uu:diva-347602 (URN)
    Available from: 2018-04-04 Created: 2018-04-04 Last updated: 2018-04-12
    5. Evaluation of  PET tracers [11C]D-deprenyl, [11C]L-dideuteriumdeprenyl and [18F]FDG for Visualization of Acute Inflammation in a Rat Model of Pain - Preliminary Findings.
    Open this publication in new window or tab >>Evaluation of  PET tracers [11C]D-deprenyl, [11C]L-dideuteriumdeprenyl and [18F]FDG for Visualization of Acute Inflammation in a Rat Model of Pain - Preliminary Findings.
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    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Purpose: Positron emission tomography with the radioligand [11C]D-deprenyl has shown an increased signal at the location of pain in patients with ankle sprains, rheumatoid arthritis and chronic whiplash injury, but the mechanism of this tracer uptake and its exact binding site in inflammation or tissue injury is still unclear. The aim of this study was to further evaluate [11C]D-deprenyl´s usefulness as a marker of acute inflammation.

    Methods: An animal PET/CT study was performed three days after the induction of a rat model of inflammatory or surgical pain. Fourteen adult male Sprague-Dawley rats and three tracers [11C]D-deprenyl, [11C]L-dideuterumdeprenyl and [18F]fluorodeoxyglucose were used.

    Results: No [11C]D-deprenyl accumulation was seen in a rat model of musculoskeletal pain. In the rat model of inflammatory pain all three ligands were shown to visualize the inflamed ankle joint with much lower uptake in the control ankle joint. The uptake was largest with [11C]D-deprenyl and [11C]L- dideuteriumdeprenyl, where approximately 1 % of the injected dose could be found in the affected ankle joint during the first minutes, whereas the uptake of [18F]FDG was approximately 0.5 % of the injected dose. However, the ratio of uptake of the injected ankle joint versus the control ankle joint was much higher for [18F]FDG (around 10 fold increase) than for the two deprenyl enantiomers (2 – 3 fold increase). The uptake pattern of [11C]D-deprenyl and [11C]L-dideuteriumdeprenyl did not show signs of specific binding or irreversible trapping.

    Conclusions: Contrary to our expectations, of the three tracers only [18F]FDG may be used as markers of peripheral inflammation in a rat model of inflammatory pain. However, as a high site-specificity is required, [11C]D-deprenyl and [11C]L-dideyteriumdeprenyl deserve further exploration regarding sensitivity, specificity and uptake mechanisms in human pain syndromes.

    Keywords
    deprenyl; inflammation; pain; PET; carbon-11
    National Category
    Medical and Health Sciences
    Research subject
    Anaesthesiology and Intensive Care
    Identifiers
    urn:nbn:se:uu:diva-347604 (URN)
    Available from: 2018-04-04 Created: 2018-04-04 Last updated: 2018-04-12
  • 2.
    Abbasinejad Enger, Shirin
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Dosimetry Studies of Different Radiotherapy Applications using Monte Carlo Radiation Transport Calculations2008Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Developing radiation delivery systems for optimisation of absorbed dose to the target without normal tissue toxicity requires advanced calculations for transport of radiation. In this thesis absorbed dose and fluence in different radiotherapy applications were calculated by using Monte Carlo (MC) simulations.

    In paper I-III external neutron activation of gadolinium (Gd) for intravascular brachytherapy (GdNCB) and tumour therapy (GdNCT) was investigated. MC codes MCNP and GEANT4 were compared. MCNP was chosen for neutron capture reaction calculations. Gd neutron capture reaction includes both very short range (Auger electrons) and long range (IC electrons and gamma) products. In GdNCB the high-energetic gamma gives an almost flat absorbed dose delivery pattern, up to 4 mm around the stent. Dose distribution at the edges and inside the stent may prevent stent edge and in-stent restenosis. For GdNCT the absorbed dose from prompt gamma will dominate over the dose from IC and Auger electrons in an in vivo situation. The absorbed dose from IC electrons will enhance the total absorbed dose in the tumours and contribute to the cell killing.

    In paper IV a model for calculation of inter-cluster cross-fire radiation dose from β-emitting radionuclides in a breast cancer model was developed. GEANT4 was used for obtaining absorbed dose. The dose internally in cells binding the isotope (self-dose) increased with decreasing β-energy except for the radionuclides with substantial amounts of conversion electrons and Auger electrons. An effective therapy approach may be a combination of radionuclides where the high self-dose from nuclides with low β-energy should be combined with the inter-cell cluster cross-fire dose from high energy β-particles.

    In paper V MC simulations using correlated sampling together with importance sampling were used to calculate spectra perturbations in detector volumes caused by the detector silicon chip and its encapsulation. Penelope and EGSnrc were used and yielded similar results. The low energy part of the electron spectrum increased but to a less extent if the silicon detector was encapsulated in low z-materials.

    List of papers
    1. Monte Carlo calculations of thermal neutron capture in gadolinium: a comparison of GEANT4 and MCNP with measurements.
    Open this publication in new window or tab >>Monte Carlo calculations of thermal neutron capture in gadolinium: a comparison of GEANT4 and MCNP with measurements.
    2006 In: Medical Physics, ISSN 0094-2405, Vol. 33, no 2, p. 337-341Article in journal (Refereed) Published
    Identifiers
    urn:nbn:se:uu:diva-97526 (URN)
    Available from: 2008-09-19 Created: 2008-09-19Bibliographically approved
    2. Gadolinium neutron capture brachytherapy (GdNCB), a new treatment method for intravascular brachytherapy.
    Open this publication in new window or tab >>Gadolinium neutron capture brachytherapy (GdNCB), a new treatment method for intravascular brachytherapy.
    2006 In: Medical Physics, ISSN 0094-2405, Vol. 33, no 1, p. 46-51Article in journal (Refereed) Published
    Identifiers
    urn:nbn:se:uu:diva-97527 (URN)
    Available from: 2008-09-19 Created: 2008-09-19Bibliographically approved
    3. Dosimetry for gadolinium neutron capture therapy (GdNCT)
    Open this publication in new window or tab >>Dosimetry for gadolinium neutron capture therapy (GdNCT)
    Manuscript (Other academic)
    Identifiers
    urn:nbn:se:uu:diva-97528 (URN)
    Available from: 2008-09-19 Created: 2008-09-19 Last updated: 2010-01-13Bibliographically approved
    4. Cross-fire doses from β-emitting radionuclides in targeted radiotherapy: A theoretical study based on experimentally measured tumor characteristics
    Open this publication in new window or tab >>Cross-fire doses from β-emitting radionuclides in targeted radiotherapy: A theoretical study based on experimentally measured tumor characteristics
    2008 (English)In: Physics in Medicine and Biology, ISSN 0031-9155, E-ISSN 1361-6560, Vol. 53, no 7, p. 1909-1920Article in journal (Refereed) Published
    Abstract [en]

    A mathematical model based upon histological findings of cell cluster distributions in primary breast cancers and lymph node metastases was developed. The model is unique because it accounts for tumor cell cluster formations within both primary tumors and metastases. The importance of inter-cell cluster cross-fire radiation dose for beta-emitting radionuclides of different energies was studied. The cell clusters were simulated as spheres with 15, 25 and 50 microm radii having a homogeneous radioactivity distribution. The self-dose as well as the dose distribution around the spheres was calculated for seven radionuclides, (90)Y, (188)Re, (32)P, (186)Re, (159)Gd, (131)I and (177)Lu using the GEANT4 Monte Carlo code. Generally, the self-dose was decreasing with increasing energy of the emitted beta particles. An exception was (188)Re which, compared to (32)P, had higher beta energy as well as higher self-dose. This was due to the higher emission of conversion and Auger electrons in the (188)Re-decay. When the cell clusters had a mean distance that was shorter than the maximum range of beta-particles, then the inter-cluster cross-fire radiation contributed significantly to the absorbed dose. Thus, high-energy beta-particles may, in spite of a low self-dose to single clusters, still be favorable to use due to the contribution of inter-cluster cross-fire radiation.

    Keywords
    Cancer, tumor, radiation, therapy
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-97529 (URN)10.1088/0031-9155/53/7/007 (DOI)000254175900007 ()18364546 (PubMedID)
    Available from: 2008-09-19 Created: 2008-09-19 Last updated: 2017-12-14Bibliographically approved
    5. Determination of self perturbations of spectra in detectors in photon fields
    Open this publication in new window or tab >>Determination of self perturbations of spectra in detectors in photon fields
    Manuscript (Other academic)
    Identifiers
    urn:nbn:se:uu:diva-97530 (URN)
    Available from: 2008-09-19 Created: 2008-09-19 Last updated: 2010-01-13Bibliographically approved
  • 3.
    Abdsaleh, Shahin
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    Core Biopsy of Breast and Axillary Lesions: Technical and Clinical Aspects2006Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The aims of this work were to image and analyze the needle behavior at automated core biopsy, to investigate the clinical utility of an alternative core biopsy technique using a semiautomated gun in breast and axillary lesions, and also to compare core biopsy with surgical specimens in malignant breast lesions regarding histologic features and hormone receptor expression.

    In two experimental studies, using butter and silicon phantoms, respectively, the needle pass was imaged and its dynamic behavior studied. It was shown that the needle took a curved course in phantoms. It deviated to the same side as where the tip lay, and the degree of the curvature increased with increasing hardness of the phantoms. Our experimental methods can be applied for imaging of needle behavior and thereby improvement of needle configuration.

    In two clinical studies, a semiautomated gun was used for large needle core biopsy of breast and axillary lesions in two series of 145 and 21 patients, respectively. The sensitivity of the method for diagnosis of malignancy was 87% (108/124), and in 37% (31/83) of cases the full length of the needle notch was filled with specimen. No injury to the neurovascular structures of the axillary area was observed. It was concluded that the semiautomated gun can be used as an alternative to the automated gun when the size and location of the lesion render use of the automatic device uncertain or dangerous, e.g., in small breast lesions or lesions located in the axilla.

    In a series of 129 cases of breast cancer, comparison of core biopsy and surgical specimens showed that core biopsy provided enough information on the histologic type and grade of the lesions. Also, there was moderate to high concordance between the two methods for assessment of progesterone receptors and estrogen receptors (Spearman`s kappa 0.67 and 0.89, respectively).

    List of papers
    1. Behaviour of the 2.1-mm (14 G) Automated Biopsy Needle in Phantoms.
    Open this publication in new window or tab >>Behaviour of the 2.1-mm (14 G) Automated Biopsy Needle in Phantoms.
    2002 In: Acta Radiologica, Vol. 43, no 2, p. 225-229Article in journal (Refereed) Published
    Identifiers
    urn:nbn:se:uu:diva-94101 (URN)
    Available from: 2006-03-03 Created: 2006-03-03Bibliographically approved
    2. Semiautomatic Core Biopsy.: A Modified Biopsy Technique in Breast Diseases.
    Open this publication in new window or tab >>Semiautomatic Core Biopsy.: A Modified Biopsy Technique in Breast Diseases.
    2003 In: Acta Radiologica, Vol. 44, no 1, p. 47-51Article in journal (Refereed) Published
    Identifiers
    urn:nbn:se:uu:diva-94102 (URN)
    Available from: 2006-03-03 Created: 2006-03-03Bibliographically approved
    3. Ultrasound-guided Large Needle Core Biopsy of the Axilla.
    Open this publication in new window or tab >>Ultrasound-guided Large Needle Core Biopsy of the Axilla.
    2004 In: Acta Radiologica, Vol. 45, no 2, p. 193-196Article in journal (Refereed) Published
    Identifiers
    urn:nbn:se:uu:diva-94103 (URN)
    Available from: 2006-03-03 Created: 2006-03-03Bibliographically approved
    4. Dynamic Behaviour of Core Biosy Needle:: High-speed Video Imaging of the Needle Course in Silicon Phantoms.
    Open this publication in new window or tab >>Dynamic Behaviour of Core Biosy Needle:: High-speed Video Imaging of the Needle Course in Silicon Phantoms.
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    Manuscript (Other academic)
    Identifiers
    urn:nbn:se:uu:diva-94104 (URN)
    Available from: 2006-03-03 Created: 2006-03-03 Last updated: 2010-01-13Bibliographically approved
    5. Comparison of Core Needle Biopsy and Surgical Specimens in Malignant Breast Lesions Regarding Histologic Features and Hormone Receptor Expression.
    Open this publication in new window or tab >>Comparison of Core Needle Biopsy and Surgical Specimens in Malignant Breast Lesions Regarding Histologic Features and Hormone Receptor Expression.
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    (English)Manuscript (Other academic)
    Identifiers
    urn:nbn:se:uu:diva-94105 (URN)
    Available from: 2006-03-03 Created: 2006-03-03 Last updated: 2010-02-03Bibliographically approved
  • 4.
    Abramenkovs, Andris
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Spiegelberg, Diana
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Otolaryngology and Head and Neck Surgery.
    Nilsson, Sten
    Department of Oncology-Pathology, Karolinska Institute, Stockholm, Sweden.
    Stenerlöw, Bo
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    The α-emitter Ra-223 induces clustered DNA damage and significantly reduces cell survivalManuscript (preprint) (Other academic)
    Abstract [en]

    The bone-seeking radiopharmaceutical Xofigo (Radium-223 dichloride) has demonstrated both extended survival and palliative effects in treatment of bone metastases in patients with prostate cancer. The alpha-particle emitter Ra-223, administered as Ra-223 dichloride, targets regions undergoing active bone remodeling and strongly binds hydroxyapatite found in bone. However, the mechanisms mediating toxicity and properties of Ra-223 binding to hydroxyapatite are not fully understood. In the current study, we show that the alpha-particles originating from the Ra-223 decay chain produce a track-like distribution of the DNA damage response proteins 53BP1 and ɣH2AX and induce high amounts of clustered DNA double-strand breaks in prostate cancer cell nuclei. The Ra-223 treatment inhibited growth of prostate cancer cells, grown in 2D- and 3D- models in vitro, independent of prostate cancer cell type and androgen receptor variant 7 (ARv7) expression. The rapid binding with a high affinity of Ra-223 to bone structures was verified in an in silico assay (KD= 19.2 ± 6.5 e-18) and almost no dissociation was detected within 24 hours. Importantly, there was no significant uptake of Ra-223 in cells. Further, we demonstrate the importance of the local dose-distribution of this treatment; there was more than 100-fold increase in cell killing when Ra-223 was attached to the bone-like hydroxyapatite structure, compared to when the radioactivity was distributed in the cell growth media. However, independent of the exposure condition, the high cell killing efficacy of the Ra-223 was attributed to the clustered DNA damaged sites induced by the released α-particles.

  • 5.
    Abramenkovs, Andris
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Spiegelberg, Diana
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Otolaryngology and Head and Neck Surgery.
    Stenerlöw, Bo
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Ra223 induced clustered DNA damage reduces cell survival independently of androgen receptor variant 7 expression2018In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 45, p. S634-S635Article in journal (Other academic)
  • 6.
    Abu Hamdeh, Sami
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Marklund, Niklas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Lannsjö, Marianne
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Rehabilitation Medicine.
    Howells, Tim
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    Raininko, Raili
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Wikström, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Neurosurgery.
    MRI analysis of diffuse axonal injury - Hemorrhagic lesions in the mesencephalon idicate poor long-term outcome2016In: MRI analysis of diffuse axonal injury - Hemorrhagic lesions in the mesencephalon idicate poor long-term outcome, Springer, 2016, Vol. 7, Suppl. 1, article id B-0814Conference paper (Refereed)
    Abstract [en]

    Purpose: Clinical outcome after traumatic diffuse axonal injury (DAI) is difficult to predict. Three MRI techniques were compared in demonstrating acute brain lesions.  Relationship of the anatomical distribution of the lesions in combination with clinical prognostic factors to outcome after 6 months was evaluated.  

    Methods and Materials: Thirty patients, aged 16-60 years (mean 31.2 years) with severe DAI (Glasgow Motor Score = GMS < 6) were examined with MRI at 1.5T within one week after the injury. A diffusion-weighted (DW) sequence (SE-EPI, b value 1000 s/mm2), a T2*-weighted gradient echo (T2*GRE) sequence and a susceptibility-weighted (SWI) sequence were evaluated by two independent reviewers with short and long neuroradiological experiences. Clinical outcome was assessed with Extended Glasgow Outcome Score (GOSE) after ≥ 6 months.

    Results: Interreviewer agreement for DAI classification was very good (ҡ 0.82 – 0.91) with all three sequences. SWI visualized more lesions than the T2*GRE or DW sequence.  In univariate analysis, number of DW lesions in the deep gray matter area including the internal capsules, number of SWI lesions in the mesencephalon, age, and GMS at admission and discharge correlated significantly with poor outcome.  Multivariate analysis only revealed an independent relation with poor outcome for age (p = 0.011) and lesions in the mesencephalic region including crura cerebri, substantia nigra and tegmentum on SWI (p = 0.032).

    Conclusion: SWI is the most sensitive technique to visualize lesions in DAI. Age over 30 years and hemorrhagic mesencephalic lesions anterior to the tectum are indicators of poor long-term outcome in DAI.

  • 7.
    Abu Hamdeh, Sami
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Enblad: Neurosurgery.
    Marklund, Niklas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Enblad: Neurosurgery.
    Lewén, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Enblad: Neurosurgery.
    Howells, Tim
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Enblad: Neurosurgery.
    Raininko, Raili
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Wikström, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Enblad, Per
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Neuroscience, Enblad: Neurosurgery.
    Intracranial pressure elevations in diffuse axonal injury: association with nonhemorrhagic MR lesions in central mesencephalic structures2019In: Journal of Neurosurgery, ISSN 0022-3085, E-ISSN 1933-0693, Vol. 131, no 2, p. 604-611Article in journal (Refereed)
    Abstract [en]

    Objective: Increased intracranial pressure (ICP) in patients with severe traumatic brain injury (TBI) with diffuse axonal injury (DAI) is not well defined. This study investigated the occurrence of increased ICP and whether clinical factors and lesion localization on MRI were associated with increased ICP in patients with DAI.

    Methods: Fifty-two patients with severe TBI (median age 24 years, range 9–61 years), who had undergone ICP monitoring and had DAI on MRI, as determined using T2*-weighted gradient echo, susceptibility-weighted imaging, and diffusion-weighted imaging (DWI) sequences, were enrolled. The proportion of good monitoring time (GMT) with ICP > 20 mm Hg during the first 120 hours postinjury was calculated and associations with clinical and MRI-related factors were evaluated using linear regression.

    Results: All patients had episodes of ICP > 20 mm Hg. The mean proportion of GMT with ICP > 20 mm Hg was 5%, and 27% of the patients (14/52) spent more than 5% of GMT with ICP > 20 mm Hg. The Glasgow Coma Scale motor score at admission (p = 0.04) and lesions on DWI sequences in the substantia nigra and mesencephalic tegmentum (SN-T, p = 0.001) were associated with the proportion of GMT with ICP > 20 mm Hg. In multivariable linear regression, lesions on DWI sequences in SN-T (8% of GMT with ICP > 20 mm Hg, 95% CI 3%–13%, p = 0.004) and young age (−0.2% of GMT with ICP > 20 mm Hg, 95% CI −0.07% to −0.3%, p = 0.002) were associated with increased ICP.

    Conclusions: Increased ICP occurs in approximately one-third of patients with severe TBI who have DAI. Age and lesions on DWI sequences in the central mesencephalon (i.e., SN-T) are associated with elevated ICP. These findings suggest that MR lesion localization may aid prediction of increased ICP in patients with DAI.

    Abbreviations: ADC = apparent diffusion coefficient; CPP = cerebral perfusion pressure; DAI = diffuse axonal injury; DWI = diffusion-weighted imaging; EVD = external ventricular drain; GCS = Glasgow Coma Scale; GMT = good monitoring time; GOSE = Glasgow Outcome Scale–Extended; ICC = intraclass correlation coefficient; ICP = intracranial pressure; MAP = mean arterial blood pressure; NICU = neurointensive care unit; SN-T = substantia nigra and mesencephalic tegmentum; SWI = susceptibility-weighted imaging; TBI = traumatic brain injury; T2*GRE = T2*-weighted gradient echo.

  • 8.
    Acosta Ruiz, Vanessa
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    CT Guided Ablation of T1 Renal Tumors2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The widespread use of medical imaging contributes to the increased detection of incidentally detected small renal tumors, a majority which are often indolent masses found in elderly patients with preexisting chronic kidney disease. In Sweden, partial nephrectomy with minimal invasive surgical approach is the current standard for removing these tumors, although another option is percutaneous image-guided tumor ablation that allows treatment of elderly patients with comorbidities for who surgery is a risk. Due to the lack of long-term follow-up studies and prospective randomized trials, ablation is still considered an alternative option to surgery in Sweden. The aim of this thesis was to evaluate treatment of T1 renal tumors with CT guided radiofrequency (RFA) and microwave ablation (MWA).

    Factors affecting the efficacy rate of complete tumor ablation with RFA after a single session were evaluated (Paper I). Optimal electrode placement and a long tumor distance to the collecting system were associated with an increased primary efficacy. Renal tumor RFA was compared with laparoscopic partial nephrectomy (LPN: Papers II-III): both methods had comparable secondary efficacy rates, but RFA involved several treatment sessions. Total session times and hospitalization times were shorter and complications less frequent for RFA than for LPN (Paper II). After treatment, renal function impact was assessed by evaluation of both renal function quantity and quality through determination of the split renal function (SRF: Paper III). Standard renal function measurements were assessed and both RFA and LPN were nephron sparing when treating small renal tumors and did not affect creatinine or GFR. However, LPN involved greater SRF reduction in the affected kidney than RFA. Initial experience with microwave ablation was evaluated and this new ablation technique demonstrated high efficacy rates with fewer complications, and was comparable with the mid-term results of now established ablation techniques (Paper IV).

    In conclusion, CT guided RFA and MWA are safe and effective treatments for the removal of T1 renal tumors. This thesis provides further insights into the field of thermal ablation of small renal masses, which can aid future treatment selection and patient management.

    List of papers
    1. Predictive factors for complete renal tumor ablation using RFA
    Open this publication in new window or tab >>Predictive factors for complete renal tumor ablation using RFA
    Show others...
    2016 (English)In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 57, no 7, p. 886-893Article in journal (Refereed) Published
    Abstract [en]

    BACKGROUND: Radiofrequency ablation (RFA) can be used to treat renal masses in patients where surgery is preferably avoided. As tumor size and location can affect ablation results, procedural planning needs to identify these factors to limit treatment to a single session and increase ablation success.

    PURPOSE: To identify factors that may affect the primary efficacy of complete renal tumor ablation with radiofrequency after a single session.

    MATERIAL AND METHODS: Percutaneous RFA (using an impedance based system) was performed using computed tomography (CT) guidance. Fifty-two renal tumors (in 44 patients) were retrospectively studied (median follow-up, 7 months). Data collection included patient demographics, tumor data (modified Renal Nephrometry Score, histopathological diagnosis), RFA treatment data (electrode placement), and follow-up results (tumor relapse). Data were analyzed through generalized estimating equations.

    RESULTS: Primary efficacy rate was 83%. Predictors for complete ablation were optimal electrode placement (P = 0.002, OR = 16.67) and increasing distance to the collecting system (P = 0.02, OR = 1.18). Tumor size was not a predictor for complete ablation (median size, 24 mm; P = 0.069, OR = 0.47), but all tumors ≤2 cm were completely ablated. All papillary tumors and oncocytomas were completely ablated in a single session; the most common incompletely ablated tumor type was clear cell carcinoma (6 of 9).

    CONCLUSION: Optimal electrode placement and a long distance from the collecting system are associated with an increased primary efficacy of renal tumor RFA. These variables need to be considered to increase primary ablation success. Further studies are needed to evaluate the effect of RFA on histopathologically different renal tumors.

    Keywords
    Radiofrequency ablation (RFA); renal tumor; predict; ablation; radiofrequency; ablation success; complete ablation
    National Category
    Radiology, Nuclear Medicine and Medical Imaging
    Identifiers
    urn:nbn:se:uu:diva-264586 (URN)10.1177/0284185115605681 (DOI)000378051200020 ()26452975 (PubMedID)
    Available from: 2015-10-15 Created: 2015-10-15 Last updated: 2019-09-04Bibliographically approved
    2. Periprocedural outcome after laparoscopic partial nephrectomy versus radiofrequency ablation for T1 renal tumors:: A modified R.E.N.A.L nephrometry score adjusted comparison.
    Open this publication in new window or tab >>Periprocedural outcome after laparoscopic partial nephrectomy versus radiofrequency ablation for T1 renal tumors:: A modified R.E.N.A.L nephrometry score adjusted comparison.
    Show others...
    2018 (English)In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 60, no 2, p. 260-268Article in journal (Refereed) Published
    Abstract [en]

    Background: Comparable oncological outcomes have been seen after surgical nephrectomy and thermal ablation of renal tumors recently. However, periprocedural outcome needs to be assessed for aiding treatment decision.

    Purpose: To compare efficacy rates and periprocedural outcome (technical success, session time, hospitalization time, and complications) after renal tumor treatment with laparoscopic partial nephrectomy (LPN) or radiofrequency ablation (RFA).

    Material and Methods: The initial experience with 49 (treated with LPN) and 84 (treated with RFA) consecutive patients for a single renal tumor (diameter ≤ 5 cm, limited to the kidney) during 2007-2014 was evaluated. Patient and tumor characteristics, efficacy rates, and periprocedural outcome were collected retrospectively. The stratified Mantel Haenzel and Van Elteren tests, adjusted for tumor complexity (with the modified R.E.N.A.L nephrometry score [m-RNS]), were used to assess differences in treatment outcomes.

    Results: Primary efficacy rate was 98% for LPN and 85.7% for RFA; secondary efficacy rate was 93.9% for LPN and 95.2% for RFA; and technical success rate was 87.8% for LPN and 100% for RFA. Median session (m-RNS adjusted P < 0.001; LPN 215 min, RFA 137 min) and median hospitalization time were longer after LPN (m-RNS adjusted P < 0.001; LPN 5 days, RFA 2 days). Side effects were uncommon (LPN 2%, RFA 4.8%). Complications were more frequent after LPN (m-RNS adjusted P < 0.001; LPN 42.9%, RFA 10.7%).

    Conclusion: Both methods achieved equivalent secondary efficacy rates. RFA included several treatment sessions, but session and hospitalization times were shorter, and complications were less frequent than for LPN. The differences remained after adjustment for renal tumor complexity.

    Keywords
    Ablation procedures, interventional, kidney, percutaneous, primary neoplasms
    National Category
    Urology and Nephrology
    Identifiers
    urn:nbn:se:uu:diva-354169 (URN)10.1177/0284185118780891 (DOI)000459621200017 ()29911400 (PubMedID)
    Available from: 2018-06-19 Created: 2018-06-19 Last updated: 2019-09-04Bibliographically approved
    3. Split Renal Function after Treatment of Small Renal Masses: Comparison between Radiofrequency Ablation and Laparoscopic Partial Nephrectomy
    Open this publication in new window or tab >>Split Renal Function after Treatment of Small Renal Masses: Comparison between Radiofrequency Ablation and Laparoscopic Partial Nephrectomy
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Radiology, Nuclear Medicine and Medical Imaging
    Identifiers
    urn:nbn:se:uu:diva-392376 (URN)
    Available from: 2019-09-03 Created: 2019-09-03 Last updated: 2019-09-04
    4. Percutaneous CT Guided Microwave Ablation of 105 T1a-T1b Renal Tumors: Technique Efficacy with a Mean 2-Year Follow-up
    Open this publication in new window or tab >>Percutaneous CT Guided Microwave Ablation of 105 T1a-T1b Renal Tumors: Technique Efficacy with a Mean 2-Year Follow-up
    Show others...
    (English)Manuscript (preprint) (Other academic)
    National Category
    Radiology, Nuclear Medicine and Medical Imaging
    Identifiers
    urn:nbn:se:uu:diva-392380 (URN)
    Available from: 2019-09-03 Created: 2019-09-03 Last updated: 2019-09-04
  • 9.
    Acosta Ruiz, Vanessa
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Båtelsson, Sarah
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Onkamo, Elina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Wernroth, Lisa
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Molecular epidemiology.
    Nilsson, Thomas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Renal Medicine.
    Lönnemark, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Dahlman, Pär
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Magnusson, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Split Renal Function after Treatment of Small Renal Masses: Comparison between Radiofrequency Ablation and Laparoscopic Partial NephrectomyManuscript (preprint) (Other academic)
  • 10.
    Acosta Ruiz, Vanessa
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Dahlman, Pär
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Brekkan, Einar
    Lönnemark, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Magnusson, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Percutaneous CT Guided Microwave Ablation of 105 T1a-T1b Renal Tumors: Technique Efficacy with a Mean 2-Year Follow-upManuscript (preprint) (Other academic)
  • 11.
    Acosta Ruiz, Vanessa
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Lönnemark, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Brekkan, Einar
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Urology.
    Dahlman, Pär
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Wernroth, Lisa
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, UCR-Uppsala Clinical Research Center. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Molecular epidemiology.
    Magnusson, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Predictive factors for complete renal tumor ablation using RFA2016In: Acta Radiologica, ISSN 0284-1851, E-ISSN 1600-0455, Vol. 57, no 7, p. 886-893Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Radiofrequency ablation (RFA) can be used to treat renal masses in patients where surgery is preferably avoided. As tumor size and location can affect ablation results, procedural planning needs to identify these factors to limit treatment to a single session and increase ablation success.

    PURPOSE: To identify factors that may affect the primary efficacy of complete renal tumor ablation with radiofrequency after a single session.

    MATERIAL AND METHODS: Percutaneous RFA (using an impedance based system) was performed using computed tomography (CT) guidance. Fifty-two renal tumors (in 44 patients) were retrospectively studied (median follow-up, 7 months). Data collection included patient demographics, tumor data (modified Renal Nephrometry Score, histopathological diagnosis), RFA treatment data (electrode placement), and follow-up results (tumor relapse). Data were analyzed through generalized estimating equations.

    RESULTS: Primary efficacy rate was 83%. Predictors for complete ablation were optimal electrode placement (P = 0.002, OR = 16.67) and increasing distance to the collecting system (P = 0.02, OR = 1.18). Tumor size was not a predictor for complete ablation (median size, 24 mm; P = 0.069, OR = 0.47), but all tumors ≤2 cm were completely ablated. All papillary tumors and oncocytomas were completely ablated in a single session; the most common incompletely ablated tumor type was clear cell carcinoma (6 of 9).

    CONCLUSION: Optimal electrode placement and a long distance from the collecting system are associated with an increased primary efficacy of renal tumor RFA. These variables need to be considered to increase primary ablation success. Further studies are needed to evaluate the effect of RFA on histopathologically different renal tumors.

  • 12.
    Adamczuk, Katarzyna
    et al.
    Katholieke Univ Leuven, Lab Cognit Neurol, B-3000 Leuven, Belgium.;Katholieke Univ Leuven, Leuven Inst Neurosci & Dis, Alzheimer Res Ctr, B-3000 Leuven, Belgium..
    Schaeverbeke, Jolien
    Katholieke Univ Leuven, Lab Cognit Neurol, B-3000 Leuven, Belgium.;Katholieke Univ Leuven, Leuven Inst Neurosci & Dis, Alzheimer Res Ctr, B-3000 Leuven, Belgium..
    Nelissen, Natalie
    Katholieke Univ Leuven, Lab Cognit Neurol, B-3000 Leuven, Belgium.;Univ Oxford, Dept Psychiat, Oxford OX3 7JX, England..
    Neyens, Veerle
    Katholieke Univ Leuven, Lab Cognit Neurol, B-3000 Leuven, Belgium.;Katholieke Univ Leuven, Leuven Inst Neurosci & Dis, Alzheimer Res Ctr, B-3000 Leuven, Belgium..
    Vandenbulcke, Mathieu
    Univ Hosp Leuven, Dept Old Age Psychiat, B-3000 Leuven, Belgium..
    Goffin, Karolien
    Katholieke Univ Leuven, Nucl Med & Mol Imaging Dept, B-3000 Leuven, Belgium.;Univ Hosp Leuven, B-3000 Leuven, Belgium..
    Lilja, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. GE Healthcare, S-75323 Uppsala, Sweden..
    Hilven, Kelly
    Katholieke Univ Leuven, Lab Neuroimmunol, B-3000 Leuven, Belgium..
    Dupont, Patrick
    Katholieke Univ Leuven, Lab Cognit Neurol, B-3000 Leuven, Belgium.;Katholieke Univ Leuven, Leuven Inst Neurosci & Dis, Alzheimer Res Ctr, B-3000 Leuven, Belgium..
    Van Laere, Koen
    Katholieke Univ Leuven, Leuven Inst Neurosci & Dis, Alzheimer Res Ctr, B-3000 Leuven, Belgium.;Katholieke Univ Leuven, Nucl Med & Mol Imaging Dept, B-3000 Leuven, Belgium.;Univ Hosp Leuven, B-3000 Leuven, Belgium..
    Vandenberghe, Rik
    Katholieke Univ Leuven, Lab Cognit Neurol, B-3000 Leuven, Belgium.;Katholieke Univ Leuven, Leuven Inst Neurosci & Dis, Alzheimer Res Ctr, B-3000 Leuven, Belgium.;Univ Hosp Leuven, Dept Neurol, B-3000 Leuven, Belgium..
    Amyloid imaging in cognitively normal older adults: comparison between F-18-flutemetamol and C-11-Pittsburgh compound B2016In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 43, no 1, p. 142-151Article in journal (Refereed)
    Abstract [en]

    Purpose Preclinical, or asymptomatic, Alzheimer's disease (AD) refers to the presence of positive AD biomarkers in the absence of cognitive deficits. This research concept is being applied to define target populations for clinical drug development. In a prospective community-recruited cohort of cognitively intact older adults, we compared two amyloid imaging markers within subjects: F-18-flutemetamol and C-11-Pittsburgh compound B (PIB). Methods In 32 community-recruited cognitively intact older adults aged between 65 and 80 years, we determined the concordance between binary classification based on F-18-flutemetamol versus C-11-PIB according to semiquantitative assessment (standardized uptake value ratio in composite cortical volume, SUVRcomp) and, alternatively, according to visual reads. We also determined the correlation between F-18-flutemetamol and C-11-PIB SUVR and evaluated how this was affected by the reference region chosen (cerebellar grey matter versus pons) and the use of partial volume correction (PVC) in this population. Results Binary classification based on semiquantitative assessment was concordant between F-18-flutemetamol and C-11-PIB in 94 % of cases. Concordance of blinded binary visual reads between tracers was 84 %. The Spearman correlation between F-18-flutemetamol and C-11-PIB SUVRcomp with cerebellar grey matter as reference region was 0.84, with a slope of 0.98. Correlations in neocortical regions were significantly lower with the pons as reference region. PVC improved the correlation in striatum and medial temporal cortex. Conclusion For the definition of preclinical AD based on F-18-flutemetamol, concordance with C-11-PIB was highest using semiquantitative assessment with cerebellar grey matter as reference region.

  • 13.
    Adams, Christopher
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Kjeldsen, Frank
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Ion Physics.
    Patriksson, Alexandra
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology.
    van Der Spoel, David
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology, Molecular biophysics.
    Gräslund, Astrid
    Papadopolous, Evangelos
    Zubarev, Roman
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology.
    Probing Solution-Phase and Gas-Phase Structures of Trp-cage Cations by Chiral Substitution and Spectroscopic Techniques2006In: International Journal of Mass Spectrometry, ISSN 1387-3806, E-ISSN 1873-2798, Vol. 253, no 3, p. 263-273Article in journal (Refereed)
    Abstract [en]

    The relevance of gas-phase protein structure to its solution structure is of the utmost importance in studying biomolecules by mass spectrometry. D-Amino acid substitutions within a minimal protein. Trp-cage. were used to correlate solution-phase properties as measured by circular dichroism with solution/gas-phase conformational features of protein cations probed via charge state distribution (CSD) in electrospray ionization. and gas-phase features revealed by tandem mass spectrometry (MS/MS). The gas-phase features were additionally supported by force-field molecular dynamics simulations. CD data showed that almost any single-residue D-substitution destroys the most prominent CD feature of the "native" all-L isomer, alpha-helicity. CSD was able to qualitatively assess the degree of compactness of solution-phase molecular structures. CSD results were consistent with the all-L form being the most compact in solution among all studied stereoisomers except for the D-Asn(1) isomer. D-substitutions of the aromatic Y(3), W(6) and Q(5) residues generated the largest deviations in CSD data among single amino acid substitutions. consistent with the critical role of these residues in Trp-cage stability. Electron capture dissociation of the stereoisomer dications gave an indication that some gas-phase structural features of Trp-cage are similar to those in solution. This result is supported by MDS data oil five of the studied stereoisomer dications in the gas-phase. The MDS-derived minimum-energy structures possessed more extensive hydrogen bonding than the solution-phase structure of the native form, deviating from the latter by 3-4 angstrom and were not 'inside-out' compared to native structures. MDS data could be correlated with CD data and even with ECD results. which aided in providing a long-range structural constraint for MDS. The overall conclusion is the general resemblance, despite the difference on the detailed level, of the preferred structures in both phases for the mini protein Trp-cage.

  • 14.
    Adjeiwaah, Mary
    et al.
    Umea Univ, Dept Radiat Sci, SE-90187 Umea, Sweden..
    Bylund, Mikael
    Umea Univ, Dept Radiat Sci, SE-90187 Umea, Sweden..
    Lundman, Josef A.
    Umea Univ, Dept Radiat Sci, SE-90187 Umea, Sweden..
    Karlsson, Camilla Thellenberg
    Umea Univ, Dept Radiat Sci, SE-90187 Umea, Sweden..
    Jonsson, Joakim H.
    Umea Univ, Dept Radiat Sci, SE-90187 Umea, Sweden..
    Nyholm, Tufve
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science. Umea Univ, Dept Radiat Sci, SE-90187 Umea, Sweden.
    Quantifying the Effect of 3T Magnetic Resonance Imaging Residual System Distortions and Patient-Induced Susceptibility Distortions on Radiation Therapy Treatment Planning for Prostate Cancer2018In: International Journal of Radiation Oncology, Biology, Physics, ISSN 0360-3016, E-ISSN 1879-355X, Vol. 100, no 2, p. 317-324Article in journal (Refereed)
    Abstract [en]

    Purpose: To investigate the effect of magnetic resonance system-and patient-induced susceptibility distortions from a 3T scanner on dose distributions for prostate cancers.

    Methods and Materials: Combined displacement fields from the residual system and patient-induced susceptibility distortions were used to distort 17 prostate patient CT images. VMAT dose plans were initially optimized on distorted CT images and the plan parameters transferred to the original patient CT images to calculate a new dose distribution.

    Results: Maximum residual mean distortions of 3.19 mm at a radial distance of 25 cm and maximum mean patient-induced susceptibility shifts of 5.8 mm were found using the lowest bandwidth of 122 Hz per pixel. There was a dose difference of <0.5% between distorted and undistorted treatment plans. The 90% confidence intervals of the mean difference between the dCT and CT treatment plans were all within an equivalence interval of (-0.5, 0.5) for all investigated plan quality measures.

    Conclusions: Patient-induced susceptibility distortions at high field strengths in closed bore magnetic resonance scanners are larger than residual system distortions after using vendor-supplied 3-dimensional correction for the delineated regions studied. However, errors in dose due to disturbed patient outline and shifts caused by patient-induced susceptibility effects are below 0.5%.

  • 15. Aguilar, Carlos
    et al.
    Edholm, Kaijsa
    Simmons, Andrew
    Cavallin, Lena
    Muller, Susanne
    Skoog, Ingmar
    Larsson, Elna-Marie
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Axelsson, Rimma
    Wahlund, Lars-Olof
    Westman, Eric
    Automated CT-based segmentation and quantification of total intracranial volume2015In: European Radiology, ISSN 0938-7994, E-ISSN 1432-1084, Vol. 25, no 11, p. 3151-3160Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES: To develop an algorithm to segment and obtain an estimate of total intracranial volume (tICV) from computed tomography (CT) images.

    MATERIALS AND METHODS: Thirty-six CT examinations from 18 patients were included. Ten patients were examined twice the same day and eight patients twice six months apart (these patients also underwent MRI). The algorithm combines morphological operations, intensity thresholding and mixture modelling. The method was validated against manual delineation and its robustness assessed from repeated imaging examinations. Using automated MRI software, the comparability with MRI was investigated. Volumes were compared based on average relative volume differences and their magnitudes; agreement was shown by a Bland-Altman analysis graph.

    RESULTS: We observed good agreement between our algorithm and manual delineation of a trained radiologist: the Pearson's correlation coefficient was r = 0.94, tICVml[manual] = 1.05 × tICVml[automated] - 33.78 (R(2) = 0.88). Bland-Altman analysis showed a bias of 31 mL and a standard deviation of 30 mL over a range of 1265 to 1526 mL.

    CONCLUSIONS: tICV measurements derived from CT using our proposed algorithm have shown to be reliable and consistent compared to manual delineation. However, it appears difficult to directly compare tICV measures between CT and MRI.

    KEY POINTS: • Automated estimation of tICV is in good agreement with manual tracing. • Consistent tICV estimations from repeated measurements demonstrate the robustness of the algorithm. • Automatically segmented volumes seem less variable than those from manual tracing. • Unbiased and automated tlCV estimation is possible from CT.

  • 16.
    Ahlgren, Sara
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Molecular Radionuclide Imaging Using Site-specifically Labelled Recombinant Affibody Molecules: Preparation and Preclinical Evaluation2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Radionuclide molecular imaging is an emerging multidisciplinary technique that is used in modern medicine to visualise diseases at cellular and molecular levels. This thesis is based on five papers (I-V) and focuses on the development of site-specific radiolabelled recombinant anti-HER2 Affibody molecules and preclinical evaluations in vitro and in vivo of the labelled conjugates. This work is part of a preclinical development of an Affibody molecule-based tracer for molecular imaging of HER2 expressing tumours.

    Papers I and II report the evaluation of the Affibody molecule ZHER2:2395-C, site-specifically labelled with the radiometals 111In (for SPECT) and 57Co (as a surrogate for 55Co, suitable for PET applications) using a thiol reactive DOTA derivative as a chelator. Both conjugates demonstrated very suitable biodistribution properties, enabling high contrast imaging just a few hours after injection.

    Papers III and IV report the development and optimization of a technique for site-specific labelling of ZHER2:2395-C with 99mTc using an N3S chelating peptide sequence. 99mTc-ZHER2:2395-C demonstrated high and specific tumour uptake and rapid clearance of non-bound tracer from the blood, resulting in high tumour-to-non-tumour ratios shortly after injection, enabling high contrast imaging. In addition, in the study described in paper IV, freeze-dried kits previously developed for 99mTc-labelling were optimised, resulting in the development of a kit in which all the reagents and protein needed for labelling of ZHER2:2395-C with 99mTc were contained in a single vial.

    Paper V reports the evaluation of an anti-HER2 Affibody molecule, ABY-025, with a fundamentally re-engineered scaffold. Despite the profound re-engineering, the biodistribution pattern of 111In-ABY-025 was very similar to that of two variants of the parental molecule.

    It seems reasonable to believe that these results will also be applicable to Affibody molecules towards other targets. Hopefully, this work will also be helpful in the development of other small proteinaceous tracers.

    List of papers
    1. Evaluation of maleimide derivative of DOTA for site-specific labeling of recombinant affibody molecules
    Open this publication in new window or tab >>Evaluation of maleimide derivative of DOTA for site-specific labeling of recombinant affibody molecules
    Show others...
    2008 (English)In: Bioconjugate chemistry, ISSN 1043-1802, E-ISSN 1520-4812, Vol. 19, no 1, p. 235-243Article in journal (Refereed) Published
    Abstract [en]

    Affibody molecules are a new class of small (7 kDa) scaffold affinity proteins, which demonstrate promising properties as agents for in vivo radionuclide targeting. The Affibody scaffold is cysteine-free and therefore independent of disulfide bonds. Thus, a single thiol group can be engineered into the protein by introduction of one cysteine. Coupling of thiol-reactive bifunctional chelators can enable site-specific labeling of recombinantly produced Affibody molecules. In this study, the use of 1,4,7,10-tetraazacyclododecane-1,4,7-tris-acetic acid-10-maleimidoethylacetamide (MMA-DOTA) for 111 In-labeling of anti-HER2 Affibody molecules His 6-Z HER2:342-Cys and Z HER2:2395-Cys has been evaluated. The introduction of a cysteine residue did not affect the affinity of the proteins, which was 29 pM for His 6-Z HER2:342-Cys and 27 pM for Z HER2:2395-Cys, comparable with 22 pM for the parental Z HER2:342. MMA-DOTA was conjugated to DTT-reduced Affibody molecules with a coupling efficiency of 93% using a 1:1 molar ratio of chelator to protein. The conjugates were labeled with 111 In to a specific radioactivity of up to 7 GBq/mmol, with preserved binding for the target HER2. In vivo, the non-His-tagged variant 111 In-[MMA-DOTA-Cys61]-Z HER2:2395-Cys demonstrated appreciably lower liver uptake than its His-tag-containing counterpart. In mice bearing HER2-expressing LS174T xenografts, 111 In-[MMA-DOTA-Cys61]-Z HER2:2395-Cys showed specific and rapid tumor localization, and rapid clearance from blood and nonspecific compartments, leading to a tumor-to-blood-ratio of 18 +/- 8 already 1 h p.i. Four hours p.i., the tumor-to-blood ratio was 138 +/- 8. Xenografts were clearly visualized already 1 h p.i.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-104530 (URN)10.1021/bc700307y (DOI)000252520300030 ()18163536 (PubMedID)
    Available from: 2009-05-29 Created: 2009-05-28 Last updated: 2017-12-13Bibliographically approved
    2. Evaluation of the Radiocobalt-Labeled [MMA-DOTA-Cys61]-ZHER2:2395-Cys Affibody Molecule for Targeting of HER2-Expressing Tumors
    Open this publication in new window or tab >>Evaluation of the Radiocobalt-Labeled [MMA-DOTA-Cys61]-ZHER2:2395-Cys Affibody Molecule for Targeting of HER2-Expressing Tumors
    2010 (English)In: Molecular Imaging and Biology, ISSN 1536-1632, E-ISSN 1860-2002, Vol. 12, no 1, p. 54-62Article in journal (Refereed) Published
    Abstract [en]

    PURPOSE: Imaging using positron emission tomography (PET) in the field of nuclear medicine is becoming increasingly important. The aim of this study was to develop a method for labeling of affibody molecules with radiocobalt for PET applications. PROCEDURES: The human epidermal growth factor receptors type 2 (HER2) binding affibody molecule DOTA-Z(2395)-C was radiolabeled with (57)Co (used as a surrogate of (55)Co). The binding specificity and cellular processing of the labeled compound was studied in vitro followed by in vivo characterization in normal and tumor-bearing mice. Furthermore, a comparative biodistribution study was performed with a (111)In-labeled counterpart. RESULTS: DOTA-Z(2395)-C was successfully labeled with radiocobalt with nearly quantitative yield. The compound displayed good retention on cells over time and high tumor accumulation of radioactivity in animal studies. Imaging studies showed clear visualization of HER2-positive tumors. Furthermore, the radiocobalt label provided better tumor-to-organ ratios than (111)In. CONCLUSIONS: Radiocobalt is a promising label for affibody molecules for future PET applications.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-122173 (URN)10.1007/s11307-009-0238-8 (DOI)000273479300008 ()19557480 (PubMedID)
    Available from: 2010-04-07 Created: 2010-04-07 Last updated: 2017-12-12Bibliographically approved
    3. Targeting of HER2-expressing tumors with a site-specifically 99mTc-labeled recombinant affibody molecule, ZHER2:2395, with C-terminally engineered cysteine
    Open this publication in new window or tab >>Targeting of HER2-expressing tumors with a site-specifically 99mTc-labeled recombinant affibody molecule, ZHER2:2395, with C-terminally engineered cysteine
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    2009 (English)In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 50, no 5, p. 781-789Article in journal (Refereed) Published
    Abstract [en]

    The detection of human epidermal growth factor receptor type 2 (HER2) expression in malignant tumors provides important information influencing patient management. Radionuclide in vivo imaging of HER2 may permit the detection of HER2 in both primary tumors and metastases by a single noninvasive procedure. Small (7 kDa) high-affinity anti-HER2 Affibody molecules may be suitable tracers for SPECT visualization of HER2-expressing tumors. The use of generator-produced (99m)Tc as a label would facilitate the prompt translation of anti-HER2 Affibody molecules into use in clinics. METHODS: A C-terminal cysteine was introduced into the Affibody molecule Z(HER2:342) to enable site-specific labeling with (99m)Tc. Two recombinant variants, His(6)-Z(HER2:342)-Cys (dissociation constant [K(D)], 29 pM) and Z(HER2:2395)-Cys, lacking a His tag (K(D), 27 pM), were labeled with (99m)Tc in yields exceeding 90%. The binding specificity and the cellular processing of Affibody molecules were studied in vitro. Biodistribution and gamma-camera imaging studies were performed in mice bearing HER2-expressing xenografts. RESULTS: (99m)Tc-His(6)-Z(HER2:342)-Cys was capable of targeting HER2-expressing SKOV-3 xenografts in SCID mice, but the liver radioactivity uptake was high. A series of comparative biodistribution experiments indicated that the presence of the His tag caused elevated accumulation in the liver. (99m)Tc-Z(HER2:2395)-Cys, not containing a His tag, showed low uptake in the liver and high and specific uptake in HER2-expressing xenografts. Four hours after injection, the radioactivity uptake values (percentage of injected activity per gram of tissue [%IA/g]) were 6.9 +/- 2.5 (mean +/- SD) %IA/g in LS174T xenografts (moderate level of HER2 expression) and 15 +/- 3 %IA/g in SKOV-3 xenografts (high level of HER2 expression). The corresponding tumor-to-blood ratios were 88 +/- 24 and 121 +/- 24, respectively. Both LS174T and SKOV-3 xenografts were clearly visualized with a clinical gamma-camera 1 h after injection of (99m)Tc-Z(HER2:2395)-Cys. CONCLUSION: The Affibody molecule (99m)Tc-Z(HER2:2395)-Cys is a promising tracer for SPECT visualization of HER2-expressing tumors.

    Keywords
    Affibody molecule, technetium, imaging, HER2, C-terminal cysteine
    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-122172 (URN)10.2967/jnumed.108.056929 (DOI)000272487900017 ()19372467 (PubMedID)
    Available from: 2010-04-07 Created: 2010-04-07 Last updated: 2017-12-12Bibliographically approved
    4. Kit formulation for 99mTc-labeling of recombinant anti-HER2 Affibody molecules with a C-terminally engineered cysteine
    Open this publication in new window or tab >>Kit formulation for 99mTc-labeling of recombinant anti-HER2 Affibody molecules with a C-terminally engineered cysteine
    2010 (English)In: Nuclear Medicine and Biology, ISSN 0969-8051, E-ISSN 1872-9614, Vol. 37, no 5, p. 539-546Article in journal (Refereed) Published
    Abstract [en]

    Introduction: Molecular imaging of HER2-expression in malignant tumors provides potentially important information for patient management. Affibody molecules have shown to be suitable tracers for imaging applications using SPECT or PET. Results from an earlier evaluation of the application of site specific 99mTc-labeling on the Affibody molecule, ZHER2:2395-C, were favorable.

    Methods: As a preparation for clinical application of this tracer we have developed and evaluated a robust single-vial freeze-dried kit, allowing labeling of the Affibody molecule, ZHER2:2395-C, with 99mTc.

    Results: The composition of the kit (containing glucoheptonate, EDTA and tin(II)-chloride), as well as the protein amount and the pertechnetate volume were optimized for a high labeling yield (> 90 %) and minimal presence of reduced hydrolyzed technetium colloids (< 1 %). The specificity to HER2 receptors, the binding competence and the stability in PBS and murine serum were verified in vitro. The shelf-life was also evaluated in vitro, showing no reduction in labeling yield or binding capacity to HER2-expressing cells after over 400 days of storage of the single-vial freeze-dried kit.

    Conclusions: ZHER2:2395-C labeled with 99mTc using the lyophilized kit was stable and resulted in a favorable biodistribution in an in vivo evaluation in normal NMRI mice.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-122175 (URN)10.1016/j.nucmedbio.2010.02.009 (DOI)000279412400002 ()20610158 (PubMedID)
    Available from: 2010-04-07 Created: 2010-04-07 Last updated: 2017-12-12Bibliographically approved
    5. Targeting of HER2-Expressing Tumors Using 111In-ABY-025, a Second-Generation Affibody Molecule with a Fundamentally Reengineered Scaffold
    Open this publication in new window or tab >>Targeting of HER2-Expressing Tumors Using 111In-ABY-025, a Second-Generation Affibody Molecule with a Fundamentally Reengineered Scaffold
    Show others...
    2010 (English)In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 51, no 7, p. 1131-1138Article in journal (Refereed) Published
    Abstract [en]

    Overexpression of HER2 in breast carcinomas predicts response to trastuzumab therapy. Affibody molecules based on a non-immunoglobulin scaffold have demon-strated high potential for in vivo molecular imaging of HER2-expressing tumors. Re-engineering of the molecular scaffold has led to a second generation of optimized Affibody molecules, having a surface distinctly different from the parental protein domain from staphylococcal protein A. The new tracer showed further increased melting point, stability and overall hydrophilicity compared to the parental molecule, and was shown to be more amenable for chemical peptide synthesis. The goal of this study was to assess potential effects of this extensive re-engineering on HER2 targeting, using ABY-025, a DOTA conjugated variant of the novel tracer.

    Methods: 111In-ABY-025 was compared with previously evaluated parent HER2-binding Affibody tracers in vitro and in vivo. The in vivo behavior was further evaluated in mice bearing SKOV-3 xenografts, in rats and in cynomolgus macaques.

    Results: 111In-ABY-025 bound specifically to HER2 in vitro and in vivo. Direct comparison with the previous generation of HER2-binding tracers showed that ABY-025 retained excellent targeting properties. Rapid blood clearance was shown in mice, rats and macaques. A highly specific tumor uptake of 16.7 ± 2.5 %IA/g was seen at 4 h after injection. The tumor-to-blood ratio was 6.3 at 0.5 h, 88 at 4 h, and increased up to 3 days after injection. Gamma camera imaging of tumors was already possible 0.5 h after injection. Furthermore, repeated i.v. administration of ABY-025 did not induce antibody formation in rats.

    Conclusions: The biodistribution of 111In-ABY-025 was in remarkably good agreement with the parent tracers, despite profound re-engineering of the non-binding surface. The molecule displayed rapid blood clearance in all species investigated and excellent targeting capacity in tumor bearing mice, leading to high tumor-to-organ-ratios and high contrast imaging shortly after injection.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:uu:diva-122176 (URN)10.2967/jnumed.109.073346 (DOI)000279430900021 ()20554729 (PubMedID)
    Available from: 2010-04-07 Created: 2010-04-07 Last updated: 2017-12-12Bibliographically approved
  • 17.
    Ahlinder, Linnea
    et al.
    Swedish Def Res Agcy, FOI, Cementvagen 20, SE-90182 Umea, Sweden..
    Lindstrom, Susanne Wiklund
    Swedish Def Res Agcy, FOI, Cementvagen 20, SE-90182 Umea, Sweden..
    Lejon, Christian
    Swedish Def Res Agcy, FOI, Cementvagen 20, SE-90182 Umea, Sweden..
    Geladi, Paul
    Swedish Univ Agr Sci, Dept Forest Biomat & Technol, SE-90183 Umea, Sweden..
    Österlund, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Noise Removal with Maintained Spatial Resolution in Raman Images of Cells Exposed to Submicron Polystyrene Particles2016In: NANOMATERIALS, ISSN 2079-4991, Vol. 6, no 5, article id UNSP 83Article in journal (Refereed)
    Abstract [en]

    The biodistribution of 300 nm polystyrene particles in A549 lung epithelial cells has been studied with confocal Raman spectroscopy. This is a label-free method in which particles and cells can be imaged without using dyes or fluorescent labels. The main drawback with Raman imaging is the comparatively low spatial resolution, which is aggravated in heterogeneous systems such as biological samples, which in addition often require long measurement times because of their weak Raman signal. Long measurement times may however induce laser-induced damage. In this study we use a super-resolution algorithm with Tikhonov regularization, intended to improve the image quality without demanding an increased number of collected pixels. Images of cells exposed to polystyrene particles have been acquired with two different step lengths, i.e., the distance between pixels, and compared to each other and to corresponding images treated with the super-resolution algorithm. It is shown that the resolution after application of super-resolution algorithms is not significantly improved compared to the theoretical limit for optical microscopy. However, to reduce noise and artefacts in the hyperspectral Raman images while maintaining the spatial resolution, we show that it is advantageous to use short mapping step lengths and super-resolution algorithms with appropriate regularization. The proposed methodology should be generally applicable for Raman imaging of biological samples and other photo-sensitive samples.

  • 18. Ahlstedt, J.
    et al.
    Orbom, A.
    Akesson, A.
    Frejd, Fredrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Strand, S.
    Tran, T.
    Simultaneous dual-radionuclide SPECT-imaging of HER2 expression using 99mTc-Affibody/111In-trastuzumab2014In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 41, no S2, p. S274-S274, article id OP522Article in journal (Other academic)
  • 19.
    Ahlström, Håkan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Ekström, Simon
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Sjöholm, Therese
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Strand, Robin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Kullberg, Joel
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Johansson, E.
    Antaros Med, Molndal, Sweden..
    Hagmar, P.
    Antaros Med, Molndal, Sweden..
    Malmberg, Filip
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Registration-based automated lesion detection and therapy evaluation of tumors in whole body PET-MR images2017In: Annals of Oncology, ISSN 0923-7534, E-ISSN 1569-8041, Vol. 28, no S5, article id 78PArticle in journal (Other academic)
  • 20.
    Ahmed, Adan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Bemötande av barn på röntgen2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Barnen är oftast rädda och oroliga då de kommer till en röntgenundersökning på grund av att det är en främmande miljö utrustad med högteknologisk apparatur som är skrämmande för barnet. För att bemöta dessa barn behöver röntgensjuksköterskan ha kunskap och färdigheter om bemötande av barn. Ett bra samspel mellan röntgensjuksköterskan och barnen som bygger på ömsesidig tillit och respekt ger trygghet hos barnet och det kan samarbeta bättre under röntgenundersökningen. På en kort tid, ofta mindre än 5 minuter, måste en röntgensjuksköterska överföra viktig information om undersökningen till barnet. Därför är det viktigt för röntgensjuksköterskan att ha kunskap om gott bemötande av barn.

  • 21.
    Ahnesjö, Anders
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    van Veelen, Bob
    Elekta Brachytherapy, NL-3905 TH Veenendaal, Netherlands..
    Tedgren, Asa Carlsson
    Linkoping Univ, Fac Hlth Sci, Dept Med & Hlth Sci IMH, Radiat Phys, SE-58185 Linkoping, Sweden.;Karolinska Univ Hosp, Dept Med Phys, Sect Radiotherapy Phys & Engn, SE-17176 Stockholm, Sweden..
    Collapsed cone dose calculations for heterogeneous tissues in brachytherapy using primary and scatter separation source data2017In: Computer Methods and Programs in Biomedicine, ISSN 0169-2607, E-ISSN 1872-7565, Vol. 139, p. 17-29Article in journal (Refereed)
    Abstract [en]

    Background and Objective: Brachytherapy is a form of radiation therapy using sealed radiation sources inserted within or in the vicinity of the tumor of, e.g., gynecological, prostate or head and neck cancers. Accurate dose calculation is a crucial part of the treatment planning. Several reviews have called for clinical software with model-based algorithms that better take into account the effects of patient individual distribution of tissues, source-channel and shielding attenuation than the commonly employed TG-43 formalism which simply map homogeneous water dose distributions onto the patient. In this paper we give a comprehensive and thorough derivation of such an algorithm based on collapsed cone point-kernel superposition, and describe details of its implementation into a commercial treatment planning system for clinical use. Methods: A brachytherapy version of the collapsed-cone algorithm using analytical raytraces of the primary photon radiation followed by successive scattering dose calculation for once and multiply scattered photons is described in detail, including derivation of the corresponding set of recursive equations for energy transport along cone axes/transport lines and the coupling to clinical source modeling. Specific implementation issues for setting up of the calculation grid, handling of intravoxel gradients and voxels partly containing non patient applicator material are given. Results: Sample runs for two clinical cases are shown, one being a gynecological application with a tungsten-shielded applicator and one a breast implant. These two cases demonstrate the impact of improved dose calculation versus TG-43 formalism. Conclusions: Use of model-based dose calculation algorithms for brachytherapy taking the three-dimensional treatment geometry into account increases the dosimetric accuracy in planning and follow up of treatments. The comprehensive description and derivations provided gives a rigid background for further clinical, educational and research applications.

  • 22.
    Ajithkumar, Thankamma
    et al.
    Cambridge Univ Hosp, Dept Oncol, Cambridge, England.
    Horan, Gail
    Cambridge Univ Hosp, Dept Oncol, Cambridge, England.
    Padovani, Laetitia
    Assistance Publ Hop Marseille, Dept Radiat Oncol, Marseille, France.
    Thorp, Nicky
    Clatterbridge Canc Ctr, Dept Oncol, Liverpool, Merseyside, England.
    Timmermann, Beate
    Univ Essen Gesamthsch, West German Proton Ctr, Essen, Germany.
    Alapetite, Claire
    Inst Curie, Dept Radiat Oncol, Paris, France;Inst Curie, Proton Ctr, Paris, France;Inst Curie, Dept Radiat Oncol, Orsay, France;Inst Curie, Proton Ctr, Orsay, France.
    Gandola, Lorenza
    Fdn IRCCS Ist Nazl Tumori, Dept Radiat Oncol, Milan, Italy.
    Ramos, Monica
    Hosp Univ Vall dHebron, Barcelona, Spain.
    Van Beek, Karen
    UZ Leuven, Radiotherapie Oncol, Leuven, Belgium.
    Christiaens, Melissa
    UZ Leuven, Radiotherapie Oncol, Leuven, Belgium.
    Lassen-Ramshad, Yasmin
    Aarhus Univ Hosp, Danish Ctr Particle Therapy, Aarhus, Denmark.
    Magelssen, Henriette
    Norwegian Radium Hosp, Oslo Univ Hosp, Dept Oncol, Oslo, Norway.
    Nilsson, Kristina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Experimental and Clinical Oncology.
    Saran, Frank
    Royal Marsden Hosp, Dept Oncol, Sutton, Surrey, England.
    Rombi, Barbara
    Santa Chiara Hosp, Proton Therapy Ctr, Trento, Italy.
    Kortmann, Rolf
    Univ Leipzig, Dept Radiat Oncol, Leipzig, Germany.
    Janssens, Geert O.
    Univ Med Ctr Utrecht, Dept Radiat Oncol, Utrecht, Netherlands;Princess Maxima Ctr Pediat Oncol, Utrecht, Netherlands.
    SIOPE - Brain tumor group consensus guideline on craniospinal target volume delineation for high-precision radiotherapy2018In: Radiotherapy and Oncology, ISSN 0167-8140, E-ISSN 1879-0887, Vol. 128, no 2, p. 192-197Article in journal (Refereed)
    Abstract [en]

    Objective: To develop a consensus guideline for craniospinal target volume (TV) delineation in children and young adults participating in SIOPE studies in the era of high-precision radiotherapy. Methods and materials: During four consensus meetings (Cambridge, Essen, Liverpool, and Marseille), conventional field-based TV has been translated into image-guided high-precision craniospinal TV by a group of expert paediatric radiation oncologists and enhanced by MRI images of liquor distribution. Results: The CTVcranial should include the whole brain, cribriform plate, most inferior part of the temporal lobes, and the pituitary fossa. If the full length of both optic nerves is not included, the dose received by different volumes of optic nerve should be recorded to correlate with future patterns of relapse (no consensus). The CTVcranial should be modified to include the dural cuffs of cranial nerves as they pass through the skull base foramina. Attempts to spare the cochlea by excluding CSF within the internal auditory canal should be avoided. The CTVspinal should include the entire subarachnoid space, including nerve roots laterally. The lower limit of the spinal CTV is at the lower limit of the thecal sac, best visible on MRI scan. There is no need to include sacral root canals in the spinal CTV. Conclusion: This consensus guideline has the potential to improve consistency of craniospinal TV delineation in an era of high-precision radiotherapy. This proposal will be incorporated in the RTQA guidelines of future SIOPE-BTG trials using CSI.

  • 23.
    Akhter, Tansim
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health.
    Larsson, Marita
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health.
    Wikström, Anna-Karin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health.
    Naessén, Tord
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Women's and Children's Health.
    Thicknesses of individual layers of artery wall indicate increased cardiovascular risk in severe pre-eclampsia2014In: Ultrasound in Obstetrics and Gynecology, ISSN 0960-7692, E-ISSN 1469-0705, Vol. 43, no 6, p. 675-680Article in journal (Refereed)
    Abstract [en]

    OBJECTIVE: Pre-eclampsia, especially severe pre-eclampsia, is associated with an increased risk of cardiovascular disease later in life. However, ultrasound assessments of the common carotid artery intima-media thickness (CCA-IMT) do not convincingly demonstrate this. The aim of this study was to assess whether the individual thickness of the CCA intima and media layers and calculation of intima/media ratio (I/M) indicate an increased cardiovascular risk in women with previous severe pre-eclampsia.

    METHODS: The thicknesses of the CCA intima and media layers were obtained by non-invasive high-frequency ultrasound (22 MHz) in 42 women with previous severe pre-eclampsia and 44 women with previous normal pregnancies. A thick intima, thin media and high I/M are signs of a less healthy artery wall.

    RESULTS: Women with previous severe pre-eclampsia had a thicker CCA intima and a higher I/M than women with previous normal pregnancies, also after adjustment for mean arterial pressure, body mass index and CCA-IMT (all p < 0.0001). CCA-IMT did not differ significantly between the groups. In receiver operating characteristic curve analysis, intima thickness and I/M clearly discriminated between women with and without previous pre-eclampsia (c value about 0.95), whereas CCA-IMT did not (c = 0.52).

    CONCLUSIONS: Estimation of the individual CCA intima and media layers using high-frequency ultrasound and calculation of the I/M clearly demonstrated the well known increased cardiovascular risk in women with pre-eclampsia, whereas CCA-IMT did not. This method appears preferable to measuring CCA-IMT for imaging arterial effects and the increased cardiovascular risk in women with previous severe pre-eclampsia.

  • 24. Alcorn, S. R.
    et al.
    Nilsson, Kristina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Oncology.
    Dieckmann, K.
    McNutt, T. R.
    Chen, M. J.
    Ermoian, R. P.
    Ford, E. C.
    MacDonald, S.
    Nechesnyuk, A.
    Tryggestad, E. J.
    Smith, K.
    Villar, R. C.
    Winey, B.
    Terezakis, S. A.
    Predictors of Setup Accuracy in Image-Guided CNS Radiation Therapy: Prospective Data From a Multinational Pediatrics Consortium2014In: International Journal of Radiation Oncology, Biology, Physics, ISSN 0360-3016, E-ISSN 1879-355X, Vol. 90, no S1, p. S723-S723Article in journal (Other academic)
  • 25.
    Alemany, Montserrat
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Stenborg, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Terent, Andreas
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences.
    Sonninen, Pirkko
    Röntgenavdelningen, Åbo universitetssjukhus, Åbo, Finland.
    Raininko, Raili
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Coexistence of microhemorrhages and acute spontaneous brain hemorrhage: correlation with signs of microangiopathy and clinical data2006In: Radiology, ISSN 0033-8419, E-ISSN 1527-1315, Vol. 238, no 1, p. 240-7Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To evaluate prospectively with magnetic resonance (MR) imaging the coexistence of microhemorrhages (MHs) in white patients with acute spontaneous intraparenchymal hemorrhage (IPH) and acute ischemic stroke and to study the association with imaging findings of microangiopathy and various clinical data. MATERIALS AND METHODS: Before examinations, informed consents were signed by either the patient or a relative. The study was carried out with the approval of the local ethics committee. MR imaging was performed in 90 patients with acute stroke: 45 with acute spontaneous IPHs (24 men and 21 women; median age, 65 and 68 years, respectively) and 45 age-matched control subjects without intracranial hemorrhages (26 men and 19 women; median age for both, 67 years), as determined at computed tomography. MR imaging included transverse T1- and T2-weighted spin-echo, transverse fluid-attenuated inversion recovery, transverse and coronal T2*-weighted gradient-echo, and, in 50 patients, diffusion-weighted sequences. Presence of MHs and signs of microangiopathy, such as T2 hyperintensities or lacunae, were recorded in the white and deep gray matter. The relationships between MH and IPH and between MH and T2 hyperintensities were analyzed by means of regression analysis. Different clinical features, such as arterial hypertension or diabetes, were registered and correlated with the image findings by means of regression analysis. RESULTS: MHs were found in 64% of patients with IPH (29 of 45) and 18% of control subjects (eight of 45). A statistically significant relationship between MH and IPH was determined (P < .001). Among the 29 patients with IPH and MH, 24 (83%) had T2 hyperintensities and 13 (45%) had lacunae; among the 16 patients without MH, seven (44%) had T2 hyperintensities and three (19%) had lacunae. A relationship between MH and occurrence and extent of T2 hyperintensities was also identified (P < .001). There was no clear relationship with the clinical data studied. CONCLUSION: The results support a correlation between the presence of imaging signs of cerebral microangiopathy, clinically silent MHs, and acute IPHs. RSNA, 2006.

  • 26.
    Alemany Ripoll, Montserrat
    Uppsala University, Medicinska vetenskapsområdet, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology.
    MRI Diagnosis of Intracranial Hemorrhage: Experimental and Clinical Studies2003Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The purpose of this work was to improve the diagnosis of intracranial hemorrhage with MRI, using, among others, T2*-w GE sequences. Various sequences were tested in rabbits at two magnetic field strengths. Then, the most effective technique was applied to stroke patients.

    Experimental studies: The MR detectability of small experimental haematomas in the brain and of blood in the cerebrospinal fluid (CSF) spaces of 30 rabbits was evaluated. MRI examinations were performed at determined intervals. The last MR images were compared to formalin fixed brain sections and, in 16 rabbits, also to the histological findings. T2*-weighted GE sequences revealed all the intraparenchymal haematomas at 1.5 T, appearing strongly hypointense. Their signal patterns remained unchanged during the follow-up. Blood in the CSF spaces was best detected at 1.5T with T2*-weighted GE sequences during the first 2 days. FLAIR and SE sequences were rather insensitive.

    Clinical studies: MR examinations were performed at 1.5T, including T1- and T2-w SE, FLAIR and T2*-w GE sequences. In the first clinical study, 66 intraparenchymal hematomas (IPH) of different sizes and ages were examined. T2*-w GE sequence was the most sensitive. On all the sequences, we found a big variety of signal patterns, without a clear relationship to the age of the hematomas.

    In a second clinical study, MR examinations were performed to 83 patients with acute stroke: 43 presented acute IPH and 40 were used as controls. Old microhemorrhages (OMHs) were found in 60% of the patients with IPH, and in 15% of the controls.

    Conclusion: T2*-weighted GE sequences are capable of revealing very small intraparenchymal hemorrhages at any stage, and blood in CSF spaces during at least the first 2 days. The age of IPHs cannot reliably be estimated with MRI. We have found a correlation between the presence of OMHs and acute intraparenchymal hematomas.

  • 27.
    Alhuseinalkhudhur, Ali
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Velikyan, Irina
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preparative Medicinal Chemistry.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Frejd, Fredrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Feldwisch, Joachim
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Lindman, Henrik
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Experimental and Clinical Oncology.
    Sörensen, Jens
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Sciences, Clinical Physiology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Kinetic Analysis of the HER2-binding ABY-025 Affibody Using Dynamic PET in Patients with Metastatic Breast Cancer2018In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 45, p. S457-S457Article in journal (Other academic)
  • 28.
    Almhagen, Erik
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science. The Skandion Clinic, Uppsala, Sweden.
    Boersma, David J.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science. ACMIT Gmbh, A-2700 Wiener Neustadt, Austria.
    Nyström, H.
    Skandion Clin, Uppsala, Sweden;DCPT, Aarhus, Denmark.
    Ahnesjö, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    A beam model for focused proton pencil beams2018In: Physica medica (Testo stampato), ISSN 1120-1797, E-ISSN 1724-191X, Vol. 52, p. 27-32Article in journal (Refereed)
    Abstract [en]

    Introduction: We present a beam model for Monte Carlo simulations of the IBA pencil beam scanning dedicated nozzle installed at the Skandion Clinic. Within the nozzle, apart from entrance and exit windows and the two ion chambers, the beam traverses vacuum, allowing for a beam that is convergent downstream of the nozzle exit. Materials and methods: We model the angular, spatial and energy distributions of the beam phase space at the nozzle exit with single Gaussians, controlled by seven energy dependent parameters. The parameters were determined from measured profiles and depth dose distributions. Verification of the beam model was done by comparing measured and GATE acquired relative dose distributions, using plan specific log files from the machine to specify beam spot positions and energy. Results: GATE-based simulations with the acquired beam model could accurately reproduce the measured data. The gamma index analysis comparing simulated and measured dose distributions resulted in > 95% global gamma index pass rates (3%/2 mm) for all depths. Conclusion: The developed beam model was found to be sufficiently accurate for use with GATE e.g. for applications in quality assurance (QA) or patient motion studies with the IBA pencil beam scanning dedicated nozzles.

  • 29.
    Almqvist, Ylva
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Sjöström, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Jensen, Holger J.
    Danmark.
    Lundqvist, Hans
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    Sundin, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Radiology.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Oncology, Radiology and Clinical Immunology, Biomedical Radiation Sciences.
    In vitro characterization of 211 At-labeled antibody A33: a potential therapeutic agent against metastatic colorectal carcinoma2005In: Cancer Biotherapy and Radiopharmaceuticals, ISSN 1084-9785, E-ISSN 1557-8852, Vol. 20, no 5, p. 514-523Article in journal (Refereed)
    Abstract [en]

    The humanized antibody A33 binds to the A33 antigen, expressed in 95% of primary and metastatic colorectal carcinomas. The restricted pattern of expression in normal tissue makes this antigen a possible target for radioimmunotherapy of colorectal micrometastases. In this study, the A33 antibody was labeled with the therapeutic nuclide 211At using N-succinimidyl para-(tri-methylstannyl)benzoate (SPMB). The in vitro characteristics of the 211At-benzoate-A33 conjugate (211At-A33) were investigated and found to be similar to those of 125I-benzoate-A33 (125I-A33) in different assays. Both conjugates bound with high affinity to SW1222 cells (Kd = 1.7 ± 0.2 nM, and 1.8 ± 0.1 nM for 211At-A33 and 125I-A33, respectively), and both showed good intracellular retention (70% of the radioactivity was still cell associated after 20 hours). The cytotoxic effect of 211At-A33 was also confirmed. After incubation with 211At-A33, SW1222 cells had a survival of approximately 0.3% when exposed to some 150 decays per cell (DPC). The cytotoxic effect was found to be dose-dependent, as cells exposed to only 56 DPC had a survival of approximately 5%. The 211At-A33 conjugate shows promise as a potential radioimmunotherapy agent for treatment of micrometastases originating from colorectal carcinoma.

  • 30.
    Altai, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Honarvar, Hadis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Wållberg, Helena
    Strand, Joanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Varasteh, Zohreh
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Dunås, Finn
    Sandström, Mattias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science.
    Rosestedt, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Löfblom, John
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Ståhl, Stefan
    Selection of an optimal cysteine-containing peptide-based chelator for labeling of Affibody molecules with 188-Re2013In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 40, no Suppl. 2, p. S219-S220Article in journal (Other academic)
    Abstract [en]

    Affibody molecules constitute a class of small (7 kDa) scaffold proteins that can be engineered to have excellent tumor targeting properties. High reabsorption in kidneys complicates development of affibody molecules for radionuclide therapy. In this study, we evaluated the influence of the composition of cysteine-containing C-terminal peptide-based chelators on the biodistribution and renal retention of 188Re-labeled anti-HER2 affibody molecules. Biodistribution of affibody molecules containing GGXC or GXGC peptide chelators (where X is G, S, E or K) was compared with biodistribution of a parental affibody molecule ZHER2:2395 having a KVDC peptide chelator. All constructs retained low picomolar affinity to HER2-expressing cells after labeling. The biodistribution of all 188Re-labeled affibody molecules was in general comparable, with the main observed difference found in the uptake and retention of radioactivity in excretory organs. The 188Re-ZHER2:V2 affibody molecule with a GGGC chelator provided the lowest uptake in all organs and tissues. The renal retention of 188Re-ZHER2:V2 (3.1±0.5 %ID/g at 4 h after injection) was 55-fold lower than retention of the parental 188Re-ZHER2:2395 (172±32 %ID/g). We show that engineering of cysteine-containing peptide-based chelators can be used for significant improvement of biodistribution of 188Re-labeled scaffold proteins, particularly reduction of their uptake in excretory organs.

  • 31.
    Altai, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Liu, H.
    KTH, Div Prot Technol, Stockholm, Sweden..
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Division of Molecular Imaging.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Gräslund, T.
    KTH, Div Prot Technol, Stockholm, Sweden..
    Improving of molecular design of a novel Affibody-fused HER2-recognising anticancer toxin using radionuclide-based techniques2016In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 43, p. S178-S178Article in journal (Refereed)
  • 32.
    Altai, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Membreno, Rosemery
    CUNY Hunter Coll, Dept Chem, New York, NY 10021 USA.;CUNY, Grad Ctr, PhD Program Chem, New York, NY USA.;Mem Sloan Kettering Canc Ctr, Dept Radiol, 1275 York Ave, New York, NY 10021 USA..
    Cook, Brendon
    CUNY Hunter Coll, Dept Chem, New York, NY 10021 USA.;CUNY, Grad Ctr, PhD Program Chem, New York, NY USA.;Mem Sloan Kettering Canc Ctr, Dept Radiol, 1275 York Ave, New York, NY 10021 USA..
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Zeglis, Brian M.
    CUNY Hunter Coll, Dept Chem, New York, NY 10021 USA.;CUNY, Grad Ctr, PhD Program Chem, New York, NY USA.;Mem Sloan Kettering Canc Ctr, Dept Radiol, 1275 York Ave, New York, NY 10021 USA..
    Pretargeted Imaging and Therapy2017In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 58, no 10, p. 1553-1559Article in journal (Refereed)
    Abstract [en]

    In vivo pretargeting stands as a promising approach to harnessing the exquisite tumor-targeting properties of antibodies for nuclear imaging and therapy while simultaneously skirting their pharmacokinetic limitations. The core premise of pretargeting lies in administering the targeting vector and radioisotope separately and having the 2 components combine within the body. In this manner, pretargeting strategies decrease the circulation time of the radioactivity, reduce the uptake of the radionuclide in healthy nontarget tissues, and facilitate the use of short-lived radionuclides that would otherwise be incompatible with antibody-based vectors. In this short review, we seek to provide a brief yet informative survey of the 4 preeminent mechanistic approaches to pretargeting, strategies predicated on streptavidin and biotin, bispecific antibodies, complementary oligonucleotides, and bioorthogonal click chemistry.

  • 33.
    Altai, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Perols, Anna
    Tsourma, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Mitran, Bogdan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Honarvar, Hadis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Robillard, Marc
    Rossin, Raffaella
    Ten Hoeve, Wolter
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Eriksson Karlström, Amelie
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Feasibility of affibody-based bioorthogonal chemistry-mediated radionuclide pretargeting2016In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 57, no 3, p. 431-436Article in journal (Refereed)
    Abstract [en]

    Affibody molecules constitute a new class of probes for radionuclide tumor targeting. The small size of affibody molecules is favorable for rapid localization in tumors and clearance from circulation. However, high renal re-absorption of affibody molecules prevents the use of residualizing radiometals, including a number of promising low energy beta- and alpha-emitters, for radionuclide therapy. We tested a hypothesis that affibody-based pretargeting mediated by a bioorthogonal interaction between trans-cyclooctene (TCO) and tetrazine would provide higher accumulation of radiometals in tumor xenografts than in the kidneys.

    Methods:

    TCO was conjugated to the anti-HER2 affibody molecule Z2395. DOTA-tetrazine was labeled with indium-111 and lutetium-177. In vitro pretargeting was studied in HER2-expressing SKOV-3 and BT474 cell lines. In vivo studies were performed on BALB/C nu/nu mice bearing SKOV-3 xenografts.

    Results:

    125I-Z2395-TCO bound specifically to HER2-expressing cells in vitro with an affinity of 45±16 pM. 111In-tetrazine bound specifically and selectively to Z2395-TCO pre-treated cells. In vivo studies demonstrated HER2-specific 125I-Z2395-TCO accumulation in xenografts. TCO-mediated 111In-tetrazine localization was shown in tumors, when the radiolabeled tracer was injected 4 h after an injection of Z2395-TCO. At 1 h post injection, the tumor uptake of 111In-tetrazine and 177Lu-tetrazine was ca. 2-fold higher than the renal uptake. Pretargeting provided more than a 56-fold reduction of renal uptake of 111In in comparison with direct targeting.

    Conclusion:

    The feasibility of affibody-based bioorthogonal chemistry-mediated pretargeting was demonstrated. The use of pretargeting provides a substantial reduction of radiometal accumulation in kidneys, creating preconditions for palliative radionuclide therapy.

  • 34.
    Altai, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Tsourma, M.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology. Dept Immunol Genet & Pathol, Uppsala, Sweden..
    Mitran, Bogdan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform. Preclin PET Platform, Uppsala, Sweden..
    Honarvar, Hadis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science. Dept Immunol Genet & Pathol, Uppsala, Sweden..
    Perols, A.
    KTH, Div Prot Technol, Stockholm, Sweden..
    Robillard, M.
    Tagworks Pharmaceut, Eindhoven, Netherlands..
    Rossin, R.
    Tagworks Pharmaceut, Eindhoven, Netherlands..
    ten Hoeve, W.
    Syncom BV, Groningen, Netherlands..
    Sandström, Mattias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Karlstrom, A. Eriksson
    KTH, Div Prot Technol, Stockholm, Sweden..
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Affibody-based bioorthogonal chemistry-mediated radionuclide pretargeting: proof-of-principle2015In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 42, no S1, p. S246-S246Article in journal (Other academic)
  • 35.
    Altai, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Westerlund, K.
    KTH, Div Prot Technol, Stockholm, Sweden..
    Velletta, J.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology.
    Honarvar, Hadis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Eriksson-Karlström, A.
    KTH, Div Prot Technol, Stockholm, Sweden..
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Comparative evaluation of Lu-177-HP2 and In-111-HP2, secondary agents for affibody-based PNA-mediated radionuclide pretargeting2016In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 43, p. S237-S237Article in journal (Refereed)
  • 36.
    Altai, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Westerlund, Kristina
    KTH Royal Inst Technol, Div Prot Technol, Sch Biotechnol, Stockholm, Sweden..
    Velletta, Justin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology.
    Mitran, Bogdan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Honarvar, Hadis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science.
    Eriksson Karlström, Amelie
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology.
    Evaluation of affibody molecule-based PNA-mediated radionuclide pretargeting: Development of an optimized conjugation protocol and 177Lu labeling2017In: Nuclear Medicine and Biology, ISSN 0969-8051, E-ISSN 1872-9614, Vol. 54, p. 1-9Article in journal (Refereed)
    Abstract [en]

    Introduction: We have previously developed a pretargeting approach for affibody-mediated cancer therapy based on PNA-PNA hybridization. In this article we have further developed this approach by optimizing the production of the primary agent, Z(HER2.342)-SR-HP1, and labeling the secondary agent, HP2, with the therapeutic radionuclide Lu-177. We also studied the biodistribution profile of Lu-177-HP2 in mice, and evaluated pretargeting with Lu-177-HP2 in vitro and in vivo.

    Methods: The biodistribution profile of Lu-177-HP2 was evaluated in NMRI mice and compared to the previously studied In-111-HP2. Pretargeting using Lu-177-HP2 was studied in vitro using the HER2-expressing cell lines BT-474 and SKOV-3, and in vivo in mice bearing SKOV-3 xenografts.

    Results and conclusion: Using an optimized production protocol for Z(HER2:342)-SR-HP1 the ligation time was reduced from 15 h to 30 min, and the yield increased from 45% to 70%. Lu-177-labeled HP2 binds specifically in vitro to BT474 and SKOV-3 cells pre-treated with Z(HER2:342)-SR-HP1.Lu-177-HP2 was shown to have a more rapid blood clearance compared to In-111-HP2 in NMRI mice, and the measured radioactivity in blood was 0.22 +/- 0.1 and 0.68 +/- 0.07%ID/g for Lu-177- and In-111-HP2, respectively, at 1 h p.i. In contrast, no significant difference in kidney uptake was observed (4.47 +/- 1.17 and 3.94 +/- 0.58%ID/g for Lu-177- and In-111-HP2, respectively, at I h p.i.). Co-injection with either Gelofusine or lysine significantly reduced the kidney uptake for Lu-177-HP2 (1.0 +/- 0.1 and 1.6 +/- 0.2, respectively, vs. 2.97 +/- 0.87%ID/g in controls at 4 h p.i.). Lu-177-HP2 accumulated in SKOV-3 xenografts in BALB/C nu/nu mice when administered after injection of Z(HER2:342)-SR-HP1. Without pre-injection of Z(HER2:342)-SR-HP1, the uptake of Lu-177-HP2 was about 90-fold lower in tumor (0.23 +/- 0.08 vs. 20.7 +/- 3.5%ID/g). The tumor-to-kidney radioactivity accumulation ratio was almost 5-fold higher in the group of mice pre-injected with Z(HER2:342)-SR-HP1. In conclusion, (177)LuHP2 was shown to be a promising secondary agent for affibody-mediated tumor pretargeting in vivo.

  • 37.
    Altai, Mohamed
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Wållberg, Helena
    Honarvar, Hadis
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Strand, Joanna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Varasteh, Zohreh
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Sandström, Mattias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Medical Radiation Sciences. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Löfblom, John
    Larsson, Erik
    Strand, Sven-Erik
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Medical Physics.
    Ståhl, Stefan
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    188Re-ZHER2:V2, a promising affibody-based targeting agent against HER2-expressing tumors: preclinical assessment2014In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 55, no 11, p. 1842-1848Article in journal (Refereed)
    Abstract [en]

    Affibody molecules are small (7 kDa) nonimmunoglobulin scaffold proteins with favorable tumor-targeting properties. Studies concerning the influence of chelators on biodistribution of 99mTc-labeled Affibody molecules demonstrated that the variant with a C-terminal glycyl-glycyl-glycyl-cysteine peptide–based chelator (designated ZHER2:V2) has the best biodistribution profile in vivo and the lowest renal retention of radioactivity. The aim of this study was to evaluate 188Re-ZHER2:V2 as a potential candidate for radionuclide therapy of human epidermal growth factor receptor type 2 (HER2)–expressing tumors.

    Methods:

    ZHER2:V2 was labeled with 188Re using a gluconate-containing kit. Targeting of HER2-overexpressing SKOV-3 ovarian carcinoma xenografts in nude mice was studied for a dosimetry assessment.

    Results:

    Binding of 188Re-ZHER2:V2 to living SKOV-3 cells was demonstrated to be specific, with an affinity of 6.4 ± 0.4 pM. The biodistribution study showed a rapid blood clearance (1.4 ± 0.1 percentage injected activity per gram [%ID/g] at 1 h after injection). The tumor uptake was 14 ± 2, 12 ± 2, 5 ± 2, and 1.8 ± 0.5 %IA/g at 1, 4, 24, and 48 h after injection, respectively. The in vivo targeting of HER2-expressing xenografts was specific. Already at 4 h after injection, tumor uptake exceeded kidney uptake (2.1 ± 0.2 %IA/g). Scintillation-camera imaging showed that tumor xenografts were the only sites with prominent accumulation of radioactivity at 4 h after injection. Based on the biokinetics, a dosimetry evaluation for humans suggests that 188Re-ZHER2:V2 would provide an absorbed dose to tumor of 79 Gy without exceeding absorbed doses of 23 Gy to kidneys and 2 Gy to bone marrow. This indicates that future human radiotherapy studies may be feasible.

    Conclusion:

    188Re-ZHER2:V2 can deliver high absorbed doses to tumors without exceeding kidney and bone marrow toxicity limits.

  • 38.
    Andersson, Camilla
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Johansson, Birgitta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Experimental and Clinical Oncology. Uppsala Univ, Oncol, Uppsala, Sweden..
    Patient experience of 18F-FDG-PET/CT in a mask fixation2016In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 43, p. S666-S666Article in journal (Refereed)
  • 39.
    Andersson, Camilla
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Johansson, Birgitta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Experimental and Clinical Oncology.
    Wassberg, Cecilia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Johansson, Silvia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Experimental and Clinical Oncology.
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Wikehult, Björn
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Patient Experience of an 18F-FDG-PET/CT Examination:: Need for Improvements in Patient Care2015In: Journal of Radiology Nursing, ISSN 1546-0843, Vol. 34, no 2, p. 100-108Article in journal (Refereed)
    Abstract [en]

    The aims of this study were to investigate the patients' knowledge about and experience of an 18F-fluoro-deoxy-glucose (FDG)-positron emission tomography (PET)/computed tomography (CT) examination and to investigate the self-reported feelings of stress, level of physical activity, and health-related quality of life (HRQoL) and to find out if this was related to how they experienced the examination. A cross-sectional survey was used to collect information on 198 patients with known or suspected malignancy. As many as 32% to 63% were satisfied with the nursing staff, the communication, and the professional skills. Most patients did not know beforehand what an FDG-PET/CT examination was. The HRQoL, level of perceived stress, and physical activity were relatively low. A better HRQoL, lower level of perceived stress, and a higher level of physical activity were correlated to a more positive experience and higher education to more knowledge about the examination (p < .01–.05). The information before the examination needs to be improved. The results may be used to improve patient care and optimize imaging procedures.

  • 40.
    Andersson, Camilla
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Johansson, Birgitta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Experimental and Clinical Oncology.
    Wassberg, Cecilia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Johansson, Silvia
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Experimental and Clinical Oncology.
    Sundin, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Ahlström, Häkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Assessment of Whether Patients' Knowledge, Satisfaction, and Experience Regarding Their 18F-Fluoride PET/CT Examination Affects Image Quality.2016In: Journal of Nuclear Medicine Technology, ISSN 0091-4916, E-ISSN 1535-5675, Vol. 44, no 1, p. 21-5Article in journal (Refereed)
    Abstract [en]

    The aim of this study was to investigate patients’ previous knowledge, satisfaction and experience regarding a (18F)-fluoride positron emission tomography / computed tomography examination ((18F)-fluoride PET/CT) and to explore whether experienced discomfort during the examination or pain was associated with reduced image quality. A further aim was to explore whether patients’ health-related quality of life (HRQoL) was associated with their satisfaction and experiences of the examination. Methods: Fifty consecutive patients with a histopathological diagnosis of prostate cancer who were scheduled for (18F)-fluoride PET/CT were asked to participate in the study, which was performed between November 2011 and April 2013. A questionnaire was used to collect information regarding the patients’ previous knowledge and experience of the examination. Image quality assessment was performed according to an arbitrary scale. The EORTC-QLQ-C30 and QLQ-PR25 were used to assess HRQoL. Results: Forty-six patients (96%) completed the questionnaires. Twenty-six per cent of participants did not know at all what a (18F)-fluoride PET/CT examination was. The majority (52-70%) were to a very high degree satisfied with the care provided by the nursing staff but less satisfied with the information given prior to the examination. The image quality was similar in patients who were exhausted or claustrophobic during the examination and those who were not. No correlations between HRQoL and the participants’ experience of (18F)-fluoride PET/CT were found. Conclusion: The majority of participants were satisfied with the care provided by the nursing staff, but there is still room for improvement especially regarding the information prior to the examination. Long examination time may be strenuous, for the patient but there was no difference in image quality between patients who felt discomfort during the examination or pain and those who did not.

  • 41.
    Andersson, Camilla
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Trampal Pulido, Carlos
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Johansson, Birgitta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Experimental and Clinical Oncology.
    Effects of web-based information on patient satisfaction and image quality in patients undergoing an 18F-FDG PET/CT examination: a randomized controlled trial2018In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 45, no Suppl 1, p. S783-S784Article in journal (Other academic)
  • 42.
    Andersson, Camilla
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Trampal Pulido, Carlos
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Johansson, Birgitta
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology.
    Randomized Controlled Trial Examining Effects of Web-Based Information on Patient Satisfaction and Image Quality in 18F-FDG PET/CT Examinations2019In: Journal of Nuclear Medicine Technology, ISSN 0091-4916, E-ISSN 1535-5675, no 1, p. 36-46Article in journal (Refereed)
    Abstract [en]

    Our aim was to compare the effect that having access, versus not having access, to web-based patient information on 18F-FDG PET/CT has on image quality and on patient satisfaction with their care during and knowledge about the examination, as well as to explore whether patients utilized and were satisfied with the web-based information.

    Methods: We recruited 148 patients between October 2015 and December 2016 and randomly assigned them to a standard-care group or an intervention group. Both groups received standard information about the 18F-FDG PET/CT examination, but the intervention group also received access to web-based information. A questionnaire was used to evaluate patient satisfaction with, knowledge about, and discomfort during the examination, and a masked assessment of image quality was conducted.

    Results: Overall satisfaction was high in both groups. The lowest satisfaction was with information about how the patients would receive the results of the examination. More patients in the intervention group than in the standard-care group knew how the 18F-FDG PET/CT examination would be conducted. Descriptive data suggest that image quality was slightly better in the intervention group than in the standard-care group, but none of the outcomes significantly differed between the groups. However, several obstacles were encountered during recruitment that led to insufficient power to detect differences. Also, only 54 of 75 patients (72%) in the intervention group utilized the web-based information. However, those who did utilize the information were satisfied with it and found it helpful.

    Conclusion: The effects of web-based information need to be investigated in a larger sample of patients. Having access to improved information before undergoing 18F-FDG PET/CT may help patients prepare for and undergo the examination. It may also improve image quality. However, this possibility needs to be investigated using image quality as the primary outcome. The results may be used to improve patient information and care and thereby optimize the 18F-FDG PET/CT procedure.

  • 43.
    Andersson, Jennie
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Rosestedt, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Asplund, Veronika
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Yavari, Nazila
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    In Vitro Therapy Modeling of HER2 Targeting Therapy in Disseminated Prostate Cancer2014In: International Journal of Oncology, ISSN 1019-6439, Vol. 45, no 5, p. 2153-2158Article in journal (Refereed)
    Abstract [en]

    Prostate cancer (PCa) is the most common cancer type among men. Treatments against advanced PCa are limited and in many cases only palliative. In a later, androgent independent, stage of PCa androgen receptors can be activated without interaction with ligand, i.e., by receptors of tyrosine kinase (RTK) family in the outlaw pathway. Human epidermal growth factor receptors HER2 and EGFR belong to RTK-family. HER2 is one of the main actors in the outlaw pathway with EGFR as the preferable heterodimerizing partner. We hypothesized that information on HER2 expression in advanced PCa could be useful for selection of patients for anti-RTK therapy and monitoring of therapy response. A panel of PCa cell lines (LNCap, PC3, DU-145) was subjected to a 8-week treatment using drugs influencing the RTK: trastuzumab (anti‑HER2), 17-DMAG (Hsp90 inhibitor), alone or in combination, and their HER2 and EGFR expressions were compared with non-treated cells. Treatment with trastuzumab decreased proliferation of LNCap and DU-145 cell lines, while 17-DMAG and trastuzumab/17‑DMAG combination affected all three cell lines. HER2 expression was significantly increased in PC3 cells, the most resistant cell line. On the contrary, in responding cells (LNCap and DU-145) HER2 expression decreased, accompanied by increased EGFR expression. However, additional treatment of cells with cetuximab (anti‑EGFR) did not give any additive effect to trastuzumab. In this study the response to anti-RTK therapy proved to vary between different PCa cell lines. We have demonstrated that RTK targeting treatments may affect the phenotypic profile of PCa tumor cells that correlates with therapy outcome. Observation of such changes during treatment could be used for monitoring and an improved therapy outcome.

  • 44. Andersson, Jesper L
    et al.
    Sundin, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Radiology. Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Section of Nuclear Medicine and PET.
    Valind, Sven
    A method for coregistration of PET and MR brain images1995In: Journal of Nuclear Medicine, ISSN 0161-5505, E-ISSN 1535-5667, Vol. 36, no 7, p. 1307-1315Article in journal (Refereed)
    Abstract [en]

    Combining MRI morphological data with functional PET data offers significant advantages in research as well as in many clinical situations. Automatic methods are needed, however, to coregister the data from the two modalities.

    METHODS:

    Simulated PET images were created by simple and automatic segmentation of MR images followed by the assignment of different uptake values to various tissue types. The simulated PET images were registered to actual PET images using a pixel-by-pixel, PET-PET registration method. The transformation matrix was then applied to the MR images. The method was used to register MRI data to PET transmission scans and emission scans obtained with FDG, nomifensine and raclopride. Validation was performed by comparing the results to those obtained by matching internal points manually defined in both volumes.

    RESULTS:

    Emission and transmission PET images were successfully registered to MR data. Comparison to the manual method indicated a registration accuracy on the order of 1-2 mm in each direction. No difference in accuracy between the different tracers was found. The error sensitivity for the method's assumptions seemed to be sufficiently low to allow complete automation of the method.

    CONCLUSION:

    We present a rapid, robust and fully automated method to register PET and MR brain images with sufficient accuracy for most clinical applications.

  • 45.
    Andersson, Jonathan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences.
    Water–fat separation in magnetic resonance imaging and its application in studies of brown adipose tissue2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Virtually all the magnetic resonance imaging (MRI) signal of a human originates from water and fat molecules. By utilizing the property chemical shift the signal can be separated, creating water- and fat-only images. From these images it is possible to calculate quantitative fat fraction (FF) images, where the value of each voxel is equal to the percentage of its signal originating from fat. In papers I and II methods for water–fat signal separation are presented and evaluated.

    The method in paper I utilizes a graph-cut to separate the signal and was designed to perform well even for a low signal-to-noise ratio (SNR). The method was shown to perform as well as previous methods at high SNRs, and better at low SNRs.

    The method presented in paper II uses convolutional neural networks to perform the signal separation. The method was shown to perform similarly to a previous method using a graph-cut when provided non-undersampled input data. Furthermore, the method was shown to be able to separate the signal using undersampled data. This may allow for accelerated MRI scans in the future.

    Brown adipose tissue (BAT) is a thermogenic organ with the main purpose of expending chemical energy to prevent the body temperature from falling too low. Its energy expending capability makes it a potential target for treating overweight/obesity and metabolic dysfunctions, such as type 2 diabetes. The most well-established way of estimating the metabolic potential of BAT is through measuring glucose uptake using 18F-fludeoxyglucose (18F-FDG) positron emission tomography (PET) during cooling. This technique exposes subjects to potentially harmful ionizing radiation, and alternative methods are desired. One alternative method is measuring the BAT FF using MRI.

    In paper III the BAT FF in 7-year olds was shown to be negatively associated with blood serum levels of the bone-specific protein osteocalcin and, after correction for adiposity, thigh muscle volume. This may have implications for how BAT interacts with both bone and muscle tissue.

    In paper IV the glucose uptake of BAT during cooling of adult humans was measured using 18F-FDG PET. Additionally, their BAT FF was measured using MRI, and their skin temperature during cooling near a major BAT depot was measured using infrared thermography (IRT). It was found that both the BAT FF and the temperature measured using IRT correlated with the BAT glucose uptake, meaning these measurements could be potential alternatives to 18F-FDG PET in future studies of BAT.

    List of papers
    1. Water-fat separation incorporating spatial smoothing is robust to noise
    Open this publication in new window or tab >>Water-fat separation incorporating spatial smoothing is robust to noise
    2018 (English)In: Magnetic Resonance Imaging, ISSN 0730-725X, E-ISSN 1873-5894, Vol. 50, p. 78-83, article id S0730-725X(18)30040-7Article in journal (Refereed) Published
    Abstract [en]

    PURPOSE: To develop and evaluate a noise-robust method for reconstruction of water and fat images for spoiled gradient multi-echo sequences.

    METHODS: The proposed method performs water-fat separation by using a graph cut to minimize an energy function consisting of unary and binary terms. Spatial smoothing is incorporated to increase robustness to noise. The graph cut can fail to find a solution covering the entire image, in which case the relative weighting of the unary term is iteratively increased until a complete solution is found. The proposed method was compared to two previously published methods. Reconstructions were performed on 16 cases taken from the 2012 ISMRM water-fat reconstruction challenge dataset, for which reference reconstructions were provided. Robustness towards noise was evaluated by reconstructing images with different levels of noise added. The percentage of water-fat swaps were calculated to measure performance.

    RESULTS: At low noise levels the proposed method produced similar results to one of the previously published methods, while outperforming the other. The proposed method significantly outperformed both of the previously published methods at moderate and high noise levels.

    CONCLUSION: By incorporating spatial smoothing, an increased robustness towards noise is achieved when performing water-fat reconstruction of spoiled gradient multi-echo sequences.

    Keywords
    Chemical shift imaging, Dixon, Graph cuts, Multi-scale, Quadratic pseudo-Boolean optimization, Water-fat separation
    National Category
    Radiology, Nuclear Medicine and Medical Imaging
    Identifiers
    urn:nbn:se:uu:diva-347450 (URN)10.1016/j.mri.2018.03.015 (DOI)000434750700011 ()29601865 (PubMedID)
    Funder
    Swedish Research Council, 2016-01040
    Available from: 2018-04-03 Created: 2018-04-03 Last updated: 2019-08-14Bibliographically approved
    2. Separation of water and fat signal in whole-body gradient echo scans using convolutional neural networks
    Open this publication in new window or tab >>Separation of water and fat signal in whole-body gradient echo scans using convolutional neural networks
    2019 (English)In: Magnetic Resonance in Medicine, ISSN 0740-3194, E-ISSN 1522-2594, Vol. 82, no 3, p. 1177-1186Article in journal (Refereed) Published
    Abstract [en]

    Purpose: To perform and evaluate water–fat signal separation of whole‐body gradient echo scans using convolutional neural networks.

    Methods: Whole‐body gradient echo scans of 240 subjects, each consisting of 5 bipolar echoes, were used. Reference fat fraction maps were created using a conventional method. Convolutional neural networks, more specifically 2D U‐nets, were trained using 5‐fold cross‐validation with 1 or several echoes as input, using the squared difference between the output and the reference fat fraction maps as the loss function. The outputs of the networks were assessed by the loss function, measured liver fat fractions, and visually. Training was performed using a graphics processing unit (GPU). Inference was performed using the GPU as well as a central processing unit (CPU).

    Results: The loss curves indicated convergence, and the final loss of the validation data decreased when using more echoes as input. The liver fat fractions could be estimated using only 1 echo, but results were improved by use of more echoes. Visual assessment found the quality of the outputs of the networks to be similar to the reference even when using only 1 echo, with slight improvements when using more echoes. Training a network took at most 28.6 h. Inference time of a whole‐body scan took at most 3.7 s using the GPU and 5.8 min using the CPU.

    Conclusion: It is possible to perform water–fat signal separation of whole‐body gradient echo scans using convolutional neural networks. Separation was possible using only 1 echo, although using more echoes improved the results.

    Keywords
    Dixon, convolutional neural network, deep learning, magnetic resonance imaging, neural network, water-fat separation
    National Category
    Radiology, Nuclear Medicine and Medical Imaging
    Identifiers
    urn:nbn:se:uu:diva-382933 (URN)10.1002/mrm.27786 (DOI)000485077600026 ()31033022 (PubMedID)
    Funder
    Swedish Research Council, 2016-01040
    Available from: 2019-05-07 Created: 2019-05-07 Last updated: 2019-10-15Bibliographically approved
    3. MRI estimates of brown adipose tissue in children - Associations to adiposity, osteocalcin, and thigh muscle volume
    Open this publication in new window or tab >>MRI estimates of brown adipose tissue in children - Associations to adiposity, osteocalcin, and thigh muscle volume
    Show others...
    2019 (English)In: Magnetic Resonance Imaging, ISSN 0730-725X, E-ISSN 1873-5894, Vol. 58, p. 135-142Article in journal (Refereed) Published
    Abstract [en]

    Context: Brown adipose tissue is of metabolic interest. The tissue is however poorly explored in children.

    Methods: Sixty-three 7-year old subjects from the Swedish birth-cohort Halland Health and Growth Study were recruited. Care was taken to include both normal weight and overweight children, but the subjects were otherwise healthy. Only children born full term were included. Water-fat separated whole-body MRI scans, anthropometric measurements, and measurements of fasting glucose and levels of energy homeostasis related hormones, including the insulin-sensitizer osteocalcin, were performed. The fat fraction (FF) and effective transverse relaxation time (T-2(star)) of suspected brown adipose tissue in the cervical-supraclavicular-axillary fat depot (sBAT) and the FFs of abdominal visceral (VAT) and subcutaneous adipose tissue (SAT) were measured. Volumes of sBAT, abdominal VAT and SAT, and thigh muscle volumes were measured.

    Results: The FF in the sBAT depot was lower than in VAT and SAT for all children. In linear correlations including sex and age as explanatory variables, sBAT FF correlated positively with all measures of adiposity (p < 0.01), except for VAT FF and weight, positively with sBAT T-2* (p = 0.036), and negatively with osteocalcin (p = 0.017). When adding measures of adiposity as explanatory variables, sBAT FF also correlated negatively with thigh muscle volume (p < 0.01).

    Conclusions: Whole-body water-fat MRI of children allows for measurements of sBAT. The FF of sBAT was lower than that of VAT and SAT, indicating presence of BAT. Future studies could confirm whether the observed correlations corresponds to a hormonally active BAT.

    Place, publisher, year, edition, pages
    ELSEVIER SCIENCE INC, 2019
    Keywords
    Brown adipose tissue, Magnetic resonance imaging, Adiposity, Osteocalcin, Muscle volume, Quantitative MRI
    National Category
    Radiology, Nuclear Medicine and Medical Imaging
    Identifiers
    urn:nbn:se:uu:diva-380416 (URN)10.1016/j.mri.2019.02.001 (DOI)000461412300018 ()30742901 (PubMedID)
    Funder
    Swedish Research Council, 2013-3013Swedish Research Council, 2016-01040Region Västra Götaland
    Available from: 2019-04-02 Created: 2019-04-02 Last updated: 2019-08-14Bibliographically approved
    4. Estimating the cold-induced brown adipose tissue glucose uptake rate measured by 18F-FDG PET using infrared thermography and water-fat separated MRI
    Open this publication in new window or tab >>Estimating the cold-induced brown adipose tissue glucose uptake rate measured by 18F-FDG PET using infrared thermography and water-fat separated MRI
    Show others...
    2019 (English)In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, article id 12358Article in journal (Refereed) Published
    Abstract [en]

    Brown adipose tissue (BAT) expends chemical energy to produce heat, which makes it a potential therapeutic target for combating metabolic dysfunction and overweight/obesity by increasing its metabolic activity. The most well-established method for measuring BAT metabolic activity is glucose uptake rate (GUR) measured using 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET). However, this is expensive and exposes the subjects to potentially harmful radiation. Cheaper and safer methods are warranted for large-scale or longitudinal studies. Potential alternatives include infrared thermography (IRT) and magnetic resonance imaging (MRI). The aim of this study was to evaluate and further develop these techniques. Twelve healthy adult subjects were studied. The BAT GUR was measured using 18F-FDG PET during individualized cooling. The temperatures of the supraclavicular fossae and a control region were measured using IRT during a simple cooling protocol. The fat fraction and effective transverse relaxation rate of BAT were measured using MRI without any cooling intervention. Simple and multiple linear regressions were employed to evaluate how well the MRI and IRT measurements could estimate the GUR. Results showed that both IRT and MRI measurements correlated with the GUR. This suggest that these measurements may be suitable for estimating the cold-induced BAT GUR in future studies.

    Keywords
    brown adipose tissue, 18F-FDG positron emission tomography, infrared thermography, magnetic resonance imagingm PET/MRI, water–fat signal separation
    National Category
    Radiology, Nuclear Medicine and Medical Imaging
    Research subject
    Radiology
    Identifiers
    urn:nbn:se:uu:diva-390410 (URN)10.1038/s41598-019-48879-7 (DOI)000482564800014 ()31451711 (PubMedID)
    Funder
    Swedish Research Council, 2016-01040Swedish Heart Lung Foundation, 2170492EXODIAB - Excellence of Diabetes Research in Sweden
    Available from: 2019-08-09 Created: 2019-08-09 Last updated: 2019-10-18Bibliographically approved
  • 46.
    Andersson, Jonathan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Antaros Med, Mölndal, Sweden.
    Kullberg, Joel
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Antaros Med, Mölndal, Sweden.
    Separation of water and fat signal in whole-body gradient echo scans using convolutional neural networks2019In: Magnetic Resonance in Medicine, ISSN 0740-3194, E-ISSN 1522-2594, Vol. 82, no 3, p. 1177-1186Article in journal (Refereed)
    Abstract [en]

    Purpose: To perform and evaluate water–fat signal separation of whole‐body gradient echo scans using convolutional neural networks.

    Methods: Whole‐body gradient echo scans of 240 subjects, each consisting of 5 bipolar echoes, were used. Reference fat fraction maps were created using a conventional method. Convolutional neural networks, more specifically 2D U‐nets, were trained using 5‐fold cross‐validation with 1 or several echoes as input, using the squared difference between the output and the reference fat fraction maps as the loss function. The outputs of the networks were assessed by the loss function, measured liver fat fractions, and visually. Training was performed using a graphics processing unit (GPU). Inference was performed using the GPU as well as a central processing unit (CPU).

    Results: The loss curves indicated convergence, and the final loss of the validation data decreased when using more echoes as input. The liver fat fractions could be estimated using only 1 echo, but results were improved by use of more echoes. Visual assessment found the quality of the outputs of the networks to be similar to the reference even when using only 1 echo, with slight improvements when using more echoes. Training a network took at most 28.6 h. Inference time of a whole‐body scan took at most 3.7 s using the GPU and 5.8 min using the CPU.

    Conclusion: It is possible to perform water–fat signal separation of whole‐body gradient echo scans using convolutional neural networks. Separation was possible using only 1 echo, although using more echoes improved the results.

  • 47.
    Andersson, Jonathan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Antaros Med, Molndal, Sweden.
    Kullberg, Joel
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Antaros Med, Molndal, Sweden.
    Water-fat separation incorporating spatial smoothing is robust to noise2018In: Magnetic Resonance Imaging, ISSN 0730-725X, E-ISSN 1873-5894, Vol. 50, p. 78-83, article id S0730-725X(18)30040-7Article in journal (Refereed)
    Abstract [en]

    PURPOSE: To develop and evaluate a noise-robust method for reconstruction of water and fat images for spoiled gradient multi-echo sequences.

    METHODS: The proposed method performs water-fat separation by using a graph cut to minimize an energy function consisting of unary and binary terms. Spatial smoothing is incorporated to increase robustness to noise. The graph cut can fail to find a solution covering the entire image, in which case the relative weighting of the unary term is iteratively increased until a complete solution is found. The proposed method was compared to two previously published methods. Reconstructions were performed on 16 cases taken from the 2012 ISMRM water-fat reconstruction challenge dataset, for which reference reconstructions were provided. Robustness towards noise was evaluated by reconstructing images with different levels of noise added. The percentage of water-fat swaps were calculated to measure performance.

    RESULTS: At low noise levels the proposed method produced similar results to one of the previously published methods, while outperforming the other. The proposed method significantly outperformed both of the previously published methods at moderate and high noise levels.

    CONCLUSION: By incorporating spatial smoothing, an increased robustness towards noise is achieved when performing water-fat reconstruction of spoiled gradient multi-echo sequences.

  • 48.
    Andersson, Jonathan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Lundström, Elin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Engström, Mathias
    GE Healthcare.
    Lubberink, Mark
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Antaros Medical.
    Kullberg, Joel
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Antaros Medical.
    Estimating the cold-induced brown adipose tissue glucose uptake rate measured by 18F-FDG PET using infrared thermography and water-fat separated MRI2019In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 9, article id 12358Article in journal (Refereed)
    Abstract [en]

    Brown adipose tissue (BAT) expends chemical energy to produce heat, which makes it a potential therapeutic target for combating metabolic dysfunction and overweight/obesity by increasing its metabolic activity. The most well-established method for measuring BAT metabolic activity is glucose uptake rate (GUR) measured using 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET). However, this is expensive and exposes the subjects to potentially harmful radiation. Cheaper and safer methods are warranted for large-scale or longitudinal studies. Potential alternatives include infrared thermography (IRT) and magnetic resonance imaging (MRI). The aim of this study was to evaluate and further develop these techniques. Twelve healthy adult subjects were studied. The BAT GUR was measured using 18F-FDG PET during individualized cooling. The temperatures of the supraclavicular fossae and a control region were measured using IRT during a simple cooling protocol. The fat fraction and effective transverse relaxation rate of BAT were measured using MRI without any cooling intervention. Simple and multiple linear regressions were employed to evaluate how well the MRI and IRT measurements could estimate the GUR. Results showed that both IRT and MRI measurements correlated with the GUR. This suggest that these measurements may be suitable for estimating the cold-induced BAT GUR in future studies.

  • 49.
    Andersson, Jonathan
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
    Roswall, Josefine
    Hallands Hosp Halmstad, Dept Pediat, Halmstad, Sweden;Univ Gothenburg, Sahlgrenska Acad, Inst Clin Sci, Dept Pediat, Gothenburg, Sweden.
    Kjellberg, Emma
    Univ Gothenburg, Sahlgrenska Acad, Inst Clin Sci, Dept Pediat, Gothenburg, Sweden.
    Ahlström, Håkan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Antaros Med, Molndal, Sweden.
    Dahlgren, Jovanna
    Univ Gothenburg, Sahlgrenska Acad, Inst Clin Sci, Dept Pediat, Gothenburg, Sweden.
    Kullberg, Joel
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology. Antaros Med, Molndal, Sweden.
    MRI estimates of brown adipose tissue in children - Associations to adiposity, osteocalcin, and thigh muscle volume2019In: Magnetic Resonance Imaging, ISSN 0730-725X, E-ISSN 1873-5894, Vol. 58, p. 135-142Article in journal (Refereed)
    Abstract [en]

    Context: Brown adipose tissue is of metabolic interest. The tissue is however poorly explored in children.

    Methods: Sixty-three 7-year old subjects from the Swedish birth-cohort Halland Health and Growth Study were recruited. Care was taken to include both normal weight and overweight children, but the subjects were otherwise healthy. Only children born full term were included. Water-fat separated whole-body MRI scans, anthropometric measurements, and measurements of fasting glucose and levels of energy homeostasis related hormones, including the insulin-sensitizer osteocalcin, were performed. The fat fraction (FF) and effective transverse relaxation time (T-2(star)) of suspected brown adipose tissue in the cervical-supraclavicular-axillary fat depot (sBAT) and the FFs of abdominal visceral (VAT) and subcutaneous adipose tissue (SAT) were measured. Volumes of sBAT, abdominal VAT and SAT, and thigh muscle volumes were measured.

    Results: The FF in the sBAT depot was lower than in VAT and SAT for all children. In linear correlations including sex and age as explanatory variables, sBAT FF correlated positively with all measures of adiposity (p < 0.01), except for VAT FF and weight, positively with sBAT T-2* (p = 0.036), and negatively with osteocalcin (p = 0.017). When adding measures of adiposity as explanatory variables, sBAT FF also correlated negatively with thigh muscle volume (p < 0.01).

    Conclusions: Whole-body water-fat MRI of children allows for measurements of sBAT. The FF of sBAT was lower than that of VAT and SAT, indicating presence of BAT. Future studies could confirm whether the observed correlations corresponds to a hormonally active BAT.

  • 50. Andersson, K. G.
    et al.
    Varasteh, Zohreh
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Rosestedt, Maria
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    Malm, M.
    Sandström, Mattias
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Medical Radiation Sciences.
    Tolmachev, Vladimir
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Radiology, Oncology and Radiation Science, Biomedical Radiation Sciences.
    Lofblom, J.
    Stahl, S.
    Orlova, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Preclinical PET Platform.
    111In-labeled NOTA-conjugated Affibody molecules for visualization of HER3 expression in malignant tumors2014In: European Journal of Nuclear Medicine and Molecular Imaging, ISSN 1619-7070, E-ISSN 1619-7089, Vol. 41, no S2, p. S311-S311, article id OP681Article in journal (Other academic)
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