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  • 1.
    Nordström, Jonny
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi. Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska och farmaceutiska vetenskapsområdet, centrumbildningar mm, Centrum för klinisk forskning, Gävleborg.
    Kero, Tanja
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi. Medical Imaging Centre, Uppsala University Hospital, Uppsala, Sweden.
    Harms, Hendrik Johannes
    Department of Nuclear Medicine and PET Centre, Aarhus University Hospital, Aarhus, Denmark.
    Widström, Charles
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi. Medical Physics, Uppsala University Hospital, Uppsala, Sweden.
    Flachskampf, Frank
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för medicinska vetenskaper, Kardiologi.
    Sörensen, Jens
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi. Medical Imaging Centre, Uppsala University Hospital, Uppsala, Sweden.
    Lubberink, Mark
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi. Medical Physics, Uppsala University Hospital, Uppsala, Sweden.
    Calculation of left ventricular volumes and ejection fraction from dynamic cardiac-gated 15O-water PET/CT: 5D-PET2017Inngår i: EJNMMI Physics, ISSN 2197-7364, E-ISSN 2191-219X, Vol. 4, nr 1, s. 26-, artikkel-id 26Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    BACKGROUND: Quantitative measurement of myocardial blood flow (MBF) is of increasing interest in the clinical assessment of patients with suspected coronary artery disease (CAD). (15)O-water positron emission tomography (PET) is considered the gold standard for non-invasive MBF measurements. However, calculation of left ventricular (LV) volumes and ejection fraction (EF) is not possible from standard (15)O-water uptake images. The purpose of the present work was to investigate the possibility of calculating LV volumes and LVEF from cardiac-gated parametric blood volume (V B) (15)O-water images and from first pass (FP) images. Sixteen patients with mitral or aortic regurgitation underwent an eight-gate dynamic cardiac-gated (15)O-water PET/CT scan and cardiac MRI. V B and FP images were generated for each gate. Calculations of end-systolic volume (ESV), end-diastolic volume (EDV), stroke volume (SV) and LVEF were performed with automatic segmentation of V B and FP images, using commercially available software. LV volumes and LVEF were calculated with surface-, count-, and volume-based methods, and the results were compared with gold standard MRI.

    RESULTS: Using V B images, high correlations between PET and MRI ESV (r = 0.89, p < 0.001), EDV (r = 0.85, p < 0.001), SV (r = 0.74, p = 0.006) and LVEF (r = 0.72, p = 0.008) were found for the volume-based method. Correlations for FP images were slightly, but not significantly, lower than those for V B images when compared to MRI. Surface- and count-based methods showed no significant difference compared with the volume-based correlations with MRI. The volume-based method showed the best agreement with MRI with no significant difference on average for EDV and LVEF but with an overestimation of values for ESV (14%, p = 0.005) and SV (18%, p = 0.004) when using V B images. Using FP images, none of the parameters showed a significant difference from MRI. Inter-operator repeatability was excellent for all parameters (ICC > 0.86, p < 0.001).

    CONCLUSION: Calculation of LV volumes and LVEF from dynamic (15)O-water PET is feasible and shows good correlation with MRI. However, the analysis method is laborious, and future work is needed for more automation to make the method more easily applicable in a clinical setting.

  • 2.
    Sjögreen Gleisner, Katarina
    et al.
    Lund Univ, Dept Med Radiat Phys, Clin Sci Lund, Lund, Sweden..
    Spezi, Emiliano
    Cardiff Univ, Sch Engn, Cardiff, S Glam, Wales..
    Solny, Pavel
    Charles Univ Prague, Motol Univ Hosp, Dept Nucl Med & Endocrinol, Fac Med 2, Prague, Czech Republic..
    Minguez Gabina, Pablo
    Gurutzeta Cruces Univ Hosp, Dept Med Phys & Radiat Protect, Baracaldo, Spain..
    Cicone, Francesco
    Sapienza Univ Rome, Dept Surg & Med Sci & Translat Med, St Andrea Hosp, Nucl Med, Rome, Italy..
    Stokke, Caroline
    Oslo Univ Hosp, Dept Diagnost Phys, Oslo, Norway..
    Chiesa, Carlo
    Fdn IRCCS Ist Nazl Tumori, Div Nucl Med, Milan, Italy..
    Paphiti, Maria
    Pammakaristos Hosp, Dept Med Phys, Athens, Greece..
    Brans, Boudewijn
    Univ Hosp, Dept Nucl Med, Ghent, Belgium.;Univ Hosp, PET Ctr, Ghent, Belgium..
    Sandström, Mattias
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Tipping, Jill
    Christie NHS Fdn Trust, Nucl Med, Manchester, Lancs, England..
    Konijnenberg, Mark
    Erasmus MC, Dept Nucl Med, Rotterdam, Netherlands..
    Flux, Glenn
    Royal Marsden Hosp, Dept Phys, Sutton, Surrey, England.;Inst Canc Res, Sutton, Surrey, England..
    Variations in the practice of molecular radiotherapy and implementation of dosimetry: results from a European survey2017Inngår i: EJNMMI Physics, ISSN 2197-7364, E-ISSN 2191-219X, Vol. 4, artikkel-id 28Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Currently, the implementation of dosimetry in molecular radiotherapy (MRT) is not well investigated, and in view of the Council Directive (2013/59/Euratom), there is a need to understand the current availability of dosimetry-based MRT in clinical practice and research studies. The aim of this study was to assess the current practice of MRT and dosimetry across European countries.

    Methods: An electronic questionnaire was distributed to European countries. This addressed 18 explicitly considered therapies, and for each therapy, a similar set of questions were included. Questions covered the number of patients and treatments during 2015, involvement of medical specialties and medical physicists, implementation of absorbed dose planning, post-therapy imaging and dosimetry, and the basis of therapy prescription.

    Results: Responses were obtained from 26 countries and 208 hospitals, administering in total 42,853 treatments. The most common therapies were I-131-NaI for benign thyroid diseases and thyroid ablation of adults. The involvement of a medical physicist (mean over all 18 therapies) was reported to be either minority or never by 32% of the responders. The percentage of responders that reported that dosimetry was included on an always/majority basis differed between the therapies and showed a median value of 36%. The highest percentages were obtained for Lu-177-PSMA therapy (100%), Y-90 microspheres of glass (84%) and resin (82%), I-131-mIBG for neuroblastoma (59%), and I-131-NaI for benign thyroid diseases (54%). The majority of therapies were prescribed based on fixed-activity protocols. The highest number of absorbed-dose based prescriptions were reported for Y-90 microsphere treatments in the liver (64% and 96% of responses for resin and glass, respectively), I-131-NaI treatment of benign thyroid diseases (38% of responses), and for I-131-mIBG treatment of neuroblastoma (18% of responses).

    Conclusions: There is a wide variation in MRT practice across Europe and for different therapies, including the extent of medical-physicist involvement and the implementation of dosimetry-guided treatments.

  • 3.
    Sousa, João M.
    et al.
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi. Uppsala Univ Hosp, PET Ctr, Uppsala, Sweden.
    Appel, Lieuwe
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi. Uppsala Univ Hosp, Med Imaging Ctr, Uppsala, Sweden.
    Engström, Mathias
    GE Healthcare, MR Appl Sci Lab, Waukesha, WI USA.
    Papadimitriou, Stergios
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Neurologi.
    Nyholm, Dag
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för neurovetenskap, Neurologi.
    Larsson, Elna-Marie
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi. Uppsala Univ Hosp, Med Imaging Ctr, Uppsala, Sweden.
    Ahlström, Håkan
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi. Uppsala Univ Hosp, Med Imaging Ctr, Uppsala, Sweden.
    Lubberink, Mark
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi. Uppsala Univ Hosp, Dept Med Phys, Uppsala, Sweden.
    Evaluation of zero-echo-time attenuation correction for integrated PET/MR brain imaging-comparison to head atlas and 68Ge-transmission-based attenuation correction2018Inngår i: EJNMMI Physics, ISSN 2197-7364, E-ISSN 2191-219X, Vol. 5, nr 20Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: MRI does not offer a direct method to obtain attenuation correction maps as its predecessors (stand-alone PET and PET/CT), and bone visualisation is particularly challenging. Recently, zero-echo-time (ZTE) was suggested for MR-based attenuation correction (AC). The aim of this work was to evaluate ZTE- and atlas-AC by comparison to 68Ge-transmission scan-based AC.

    Nine patients underwent brain PET/MR and stand-alone PET scanning using the dopamine transporter ligand 11C-PE2I. For each of them, two AC maps were obtained from the MR images: an atlas-based, obtained from T1-weighted LAVA-FLEX imaging with cortical bone inserted using a CT-based atlas, and an AC map generated from proton-density-weighted ZTE images. Stand-alone PET 68Ge-transmission AC map was used as gold standard. PET images were reconstructed using the three AC methods and standardised uptake value (SUV) values for the striatal, limbic and cortical regions, as well as the cerebellum (VOIs) were compared. SUV ratio (SUVR) values normalised for the cerebellum were also assessed. Bias, precision and agreement were calculated; statistical significance was evaluated using Wilcoxon matched-pairs signed-rank test.

    Results: Both ZTE- and atlas-AC showed a similar bias of 6–8% in SUV values across the regions. Correlation coefficients with 68Ge-AC were consistently high for ZTE-AC (r 0.99 for all regions), whereas they were lower for atlas-AC, varying from 0.99 in the striatum to 0.88 in the posterior cortical regions. SUVR showed an overall bias of 2.9 and 0.5% for atlas-AC and ZTE-AC, respectively. Correlations with 68Ge-AC were higher for ZTE-AC, varying from 0.99 in the striatum to 0.96 in the limbic regions, compared to atlas-AC (0.99 striatum to 0.77 posterior cortex).

    Conclusions: Absolute SUV values showed less variability for ZTE-AC than for atlas-AC when compared to 68Ge-AC, but bias was similar for both methods. This bias is largely caused by higher linear attenuation coefficients in atlas- and ZTE-AC image compared to 68Ge-images. For SUVR, bias was lower when using ZTE-AC than for atlas-AC. ZTE-AC shows to be a more robust technique than atlas-AC in terms of both intra- and inter-patient variability.

  • 4.
    Stokke, Caroline
    et al.
    Oslo Univ Hosp, Dept Diagnost Phys, Oslo, Norway..
    Gabina, Pablo Minguez
    Gurutzeta Cruces Univ Hosp, Dept Med Phys & Radiat Protect, Baracaldo, Spain..
    Solny, Pavel
    Czech Tech Univ, Dept Dosimetry & Applicat Ionizing Radiat, Prague, Czech Republic..
    Cicone, Francesco
    Sapienza Univ Rome, St Andrea Hosp, Dept Surg & Med Sci & Translat Med, Nucl Med, Rome, Italy..
    Sandström, Mattias
    Uppsala universitet, Medicinska och farmaceutiska vetenskapsområdet, Medicinska fakulteten, Institutionen för kirurgiska vetenskaper, Radiologi.
    Gleisner, Katarina Sjögreen
    Lund Univ, Dept Med Radiat Phys, Clin Sci Lund, Lund, Sweden..
    Chiesa, Carlo
    Fdn IRCCS Ist Nazl Tumori, Nucl Med Div, Milan, Italy..
    Spezi, Emiliano
    Cardiff Univ, Sch Engn, Cardiff, S Glam, Wales..
    Paphiti, Maria
    Pammakaristos Hosp, Dept Med Phys, Athens, Greece..
    Konijnenberg, Mark
    Erasmus MC, Dept Radiol & Nucl Med, Rotterdam, Netherlands..
    Aldridge, Matt
    UCL Inst Nucl Med, Nucl Med Radiotherapy Phys, London, England.;UCL Hosp NHS Fdn Trust, London, England..
    Tipping, Jill
    Christie NHS Fdn Trust, Nucl Med, Manchester, Lancs, England..
    Wissmeyer, Michael
    Univ Hosp Geneva, Dept Nucl Med, Geneva, Switzerland..
    Brans, Boudewijn
    Univ Hosp, Dept Nucl Med, Ghent, Belgium.;Univ Hosp, PET Ctr, Ghent, Belgium..
    Bacher, Klaus
    Univ Ghent, Div Med Phys, Dept Basic Med Sci, Ghent, Belgium..
    Kobe, Carsten
    Univ Hosp Cologne, Dept Nucl Med, Cologne, Germany..
    Flux, Glenn
    Royal Marsden Hosp, Joint Dept Phys, Sutton, Surrey, England.;Inst Canc Res, Sutton, Surrey, England..
    Dosimetry-based treatment planning for molecular radiotherapy: a summary of the 2017 report from the Internal Dosimetry Task Force2017Inngår i: EJNMMI Physics, ISSN 2197-7364, E-ISSN 2191-219X, Vol. 4, artikkel-id 27Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The European directive on basic safety standards (Council directive 2013/59 Euratom) mandates dosimetry-based treatment planning for radiopharmaceutical therapies. The directive comes into operation February 2018, and the aim of a report produced by the Internal Dosimetry Task Force of the European Association of Nuclear Medicine is to address this aspect of the directive. A summary of the report is presented. A brief review of five of the most common therapy procedures is included in the current text, focused on the potential to perform patient-specific dosimetry. In the full report, 11 different therapeutic procedures are included, allowing additional considerations of effectiveness, references to specific literature on quantitative imaging and dosimetry, and existing evidence for absorbed dose-effect correlations for each treatment. Individualized treatment planning with tracer diagnostics and verification of the absorbed doses delivered following therapy is found to be scientifically feasible for almost all procedures investigated, using quantitative imaging and/or external monitoring. Translation of this directive into clinical practice will have significant implications for resource requirements. Molecular radiotherapy is undergoing a significant expansion, and the groundwork for dosimetry-based treatment planning is already in place. The mandated individualization is likely to improve the effectiveness of the treatments, although must be adequately resourced.

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