uu.seUppsala University Publications
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Perfusion MRI of the brain after radiotherapy in patients with glioblastoma – potential and problems
Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Surgical Sciences, Radiology.
2018 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Perfusion Magnetic Resonance Imaging (MRI) is a useful tool in diagnostic evaluation and treatment response assessment in patients with glioblastoma. The standard treatment regimen includes surgical resection, radiotherapy and adjuvant chemotherapy. However, prognosis is poor; relative 5-year survival is 3–5%. Radiotherapy sequelae may have considerable negative effects on the patients’ quality of life. Acute and early delayed radiation-induced injury is primarily considered damage to the cerebral vascular tissue.

 

The general aim of this study was to evaluate how perfusion MRI evaluation, based on contrast agent administration (DSC- and DCE-MRI), is affected by or can be useful to assess radiation-induced changes in normal appearing brain tissue in patients with glioblastoma after radiotherapy.

 

Paper I: Dynamic Susceptibility Contrast (DSC)-MRI is a common perfusion MRI method in clinical practice in patients with glioblastoma. Due to inherent limitations, cerebral blood volume (CBV) and cerebral blood flow (CBF) derived from DSC-MRI are normalized to contralateral normal appearing white matter. Ten patients with glioblastoma were examined. Regional and global normalized CBV and normalized CBF in white and gray matter decreased after radiotherapy, followed by a tendency to recover. The response of nCBV and nCBF was dose-dependent in white matter but not in gray matter. In conclusion, radiotherapy effects on normal appearing white matter can confound treatment evaluation with DSC-MRI in patients with glioblastoma.

 

Paper II: Dynamic Contrast Enhanced (DCE)-MRI may be useful in evaluating radiation-induced damage in normal appearing brain tissue.  DCE-MRI-derived parameters, vascular permeability (Ktrans) and the fractional volume of the extravascular extracellular space (Ve) are potential biomarkers. Twelve patients with glioblastoma were examined. A tendency toward increased Ktrans and Ve was seen, suggesting that these parameters may act as potential biomarkers for acute and early delayed radiation-induced vascular damage

Place, publisher, year, edition, pages
Uppsala: Uppsala universitet, 2018.
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
URN: urn:nbn:se:uu:diva-346814OAI: oai:DiVA.org:uu-346814DiVA, id: diva2:1194647
Presentation
2018-04-13, Akademiska Sjukhuset, Uppsala, 12:00 (Swedish)
Supervisors
Available from: 2018-04-04 Created: 2018-04-03 Last updated: 2020-05-15Bibliographically approved
List of papers
1. Perfusion Magnetic Resonance Imaging Changes in Normal Appearing Brain Tissue after Radiotherapy in Glioblastoma Patients may Confound Longitudinal Evaluation of Treatment Response
Open this publication in new window or tab >>Perfusion Magnetic Resonance Imaging Changes in Normal Appearing Brain Tissue after Radiotherapy in Glioblastoma Patients may Confound Longitudinal Evaluation of Treatment Response
2018 (English)In: Radiology and Oncology, ISSN 1318-2099, E-ISSN 1581-3207, Vol. 52, no 2, p. 143-151Article in journal (Refereed) Published
Abstract [en]

Background: The aim of this study was assess acute and early delayed radiation-induced changes in normal-appearing brain tissue perfusion as measured with perfusion magnetic resonance imaging (MRI) and the dependence of these changes on the fractionated radiotherapy (FRT) dose level.

Patients and methods: Seventeen patients with glioma WHO grade III-IV treated with FRT were included in this prospective study, seven were excluded because of inconsistent FRT protocol or missing examinations. Dynamic susceptibility contrast MRI and contrast-enhanced 3D-T1-weighted (3D-T1w) images were acquired prior to and in average (standard deviation): 3.1 (3.3), 34.4 (9.5) and 103.3 (12.9) days after FRT. Pre-FRT 3D-T1w images were segmented into white- and grey matter. Cerebral blood volume (CBV) and cerebral blood flow (CBF) maps were calculated and co-registered patient-wise to pre-FRT 3D-T1w images. Seven radiation dose regions were created for each tissue type: 0-5 Gy, 5-10 Gy, 10-20 Gy, 20-30 Gy, 30-40 Gy, 40-50 Gy and 50-60 Gy. Mean CBV and CBF were calculated in each dose region and normalised (nCBV and nCBF) to the mean CBV and CBF in 0-5 Gy white- and grey matter reference regions, respectively.

Results: Regional and global nCBV and nCBF in white- and grey matter decreased after FRT, followed by a tendency to recover. The response of nCBV and nCBF was dose-dependent in white matter but not in grey matter.

Conclusions: Our data suggest that radiation-induced perfusion changes occur in normal-appearing brain tissue after FRT. This can cause an overestimation of relative tumour perfusion using dynamic susceptibility contrast MRI, and can thus confound tumour treatment evaluation.

Keywords
malignant gliomas, normal-appearing brain tissue, perfusion MRI, radiation-induced changes
National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:uu:diva-356784 (URN)10.2478/raon-2018-0022 (DOI)000433103400004 ()30018517 (PubMedID)
Funder
Swedish Cancer Society
Available from: 2018-08-07 Created: 2018-08-07 Last updated: 2020-05-15Bibliographically approved
2. Dynamic Contrast-Enhanced Magnetic Resonance Imaging May Act as a Biomarker for Vascular Damage in Normal Appearing Brain Tissue after Radiotherapy in Patients with Glioblastoma
Open this publication in new window or tab >>Dynamic Contrast-Enhanced Magnetic Resonance Imaging May Act as a Biomarker for Vascular Damage in Normal Appearing Brain Tissue after Radiotherapy in Patients with Glioblastoma
Show others...
2018 (English)In: Acta Radiologica Open, ISSN 2058-4601, Vol. 7, no 11Article in journal (Refereed) Published
Abstract [en]

Background: Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is a promising perfusion method and may be useful in evaluating radiation-induced changes in normal-appearing brain tissue.

Purpose: To assess whether radiotherapy induces changes in vascular permeability (Ktrans) and the fractional volume of the extravascular extracellular space (Ve) derived from DCE-MRI in normal-appearing brain tissue and possible relationships to radiation dose given.

Material and Methods: Seventeen patients with glioblastoma treated with radiotherapy and chemotherapy were included; five were excluded because of inconsistencies in the radiotherapy protocol or early drop-out. DCE-MRI, contrast-enhanced three-dimensional (3D) T1-weighted (T1W) images and T2-weighted fluid attenuated inversion recovery (T2-FLAIR) images were acquired before and on average 3.3, 30.6, 101.6, and 185.7 days after radiotherapy. Pre-radiotherapy CE T1W and T2-FLAIR images were segmented into white and gray matter, excluding all non-healthy tissue. Ktrans and Ve were calculated using the extended Kety model with the Parker population-based arterial input function. Six radiation dose regions were created for each tissue type, based on each patient's computed tomography-based dose plan. Mean Ktrans and Ve were calculated over each dose region and tissue type.

Results: Global Ktrans and Ve demonstrated mostly non-significant changes with mean values higher for post-radiotherapy examinations in both gray and white matter compared to pre-radiotherapy. No relationship to radiation dose was found.

Conclusion: Additional studies are needed to validate if Ktrans and Ve derived from DCE-MRI may act as potential biomarkers for acute and early-delayed radiation-induced vascular damages. No dose-response relationship was found.

National Category
Radiology, Nuclear Medicine and Medical Imaging
Identifiers
urn:nbn:se:uu:diva-346813 (URN)10.1177/2058460118808811 (DOI)000450106500001 ()30542625 (PubMedID)
Funder
Swedish Cancer Society
Available from: 2018-03-21 Created: 2018-03-21 Last updated: 2020-03-01Bibliographically approved

Open Access in DiVA

No full text in DiVA

Authority records BETA

Fahlström, Markus

Search in DiVA

By author/editor
Fahlström, Markus
By organisation
Radiology
Radiology, Nuclear Medicine and Medical Imaging

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 367 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf