NIMG-74. RESPONSE ASSESSMENT AFTER DOSE-ESCALATED RADIOTHERAPY: IMAGING PROTOCOL OF A MULTICENTER PHASE III TRIAL ON INTRAOPERATIVE RADIOTHERAPY IN NEWLY DIAGNOSED GLIOBLASTOMA (INTRAGO-II;ARO2016-1;AG-NRO-03)

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi146-vi146
Author(s):  
Whitney Pope ◽  
Kevin Petrecca ◽  
Alexander Radbruch ◽  
Frank Giordano ◽  
Keyword(s):  
Cerebral Blood Volume ◽  
Intraoperative Radiotherapy ◽  
Response Assessment ◽  
Phase Iii ◽  
Dynamic Susceptibility ◽  
Dynamic Susceptibility Contrast ◽  
Radiological Progression ◽  
Imaging Protocol ◽  
Phase Iii Trial ◽  
Post Irradiation

Abstract BACKGROUND Reliable response assessment of irradiated glioblastomas remains challenging. In an attempt to better distinguish post-therapeutic alterations (such as reactive gliosis, pseudoprogression and radionecrosis) from tumor progression, especially after (local) RT dose escalation as performed in the multinational INTRAGO-II trial, we modified the classical RANO criteria and developed a protocol and workflow for uniform assessment of post-irradiation tumor response. METHODS INTRAGO-II is a multinational randomized phase III trial (9 nations, 19 centers) that evaluates the benefit of intraoperative radiotherapy (IORT) with 20-30 Gy to the tumor bed after resection of glioblastoma in addition to standard of care (NCT02685605). Within this trial, advanced imaging is mandatory in addition to standard sequences and measurements (such as the sum of the products of perpendicular diameters, SPD). Specifically, the acquisition of dynamic susceptibility contrast (DSC) sequences as well as the calculation of the normalized relative cerebral blood volume (rCBV) is required. All local assessments are subjected to a central neuroradiology read, which is conclusive. The key modifications to RANO are that (i) an ≥25% increase SPD of the target lesions should be associated with a rCBV≥1 of at least one lesion to be considered radiological progression, (ii) new enhancing lesions should become measurable before they can constitute to radiological progression, (iii) rCBV is normalized against normal appearing white matter from the contralateral brain by reference ROI (with a minimal sphere size of 5x5mm) and (iv) confirmatory scans are mandatory for defining progressive disease. CONCLUSION/SUMMARY We present an imaging protocol based on updated RANO that accounts for post-irradiation image alterations. Funding: Carl Zeiss Meditec AG, Germany and MedWave Medical Imaging BV; Registered with ClinicalTrials.gov, number NCT02685605.

scholarly journals The effect of carotid artery stenting on capillary transit time heterogeneity in patients with carotid artery stenosis

2018 ◽  
Vol 3 (3) ◽  
pp. 263-271 ◽  
Author(s):  
Ethem M Arsava ◽  
Mikkel B Hansen ◽  
Berkan Kaplan ◽  
Ahmet Peker ◽  
Rahsan Gocmen ◽  
...  
Keyword(s):  
Carotid Artery ◽  
Transit Time ◽  
Carotid Artery Stenting ◽  
Cerebral Blood Volume ◽  
Mean Transit Time ◽  
Oxygen Extraction Fraction ◽  
Consecutive Series ◽  
Dynamic Susceptibility ◽  
Dynamic Susceptibility Contrast ◽  
Vascular Events

Introduction Carotid revascularisation improves haemodynamic compromise in cerebral circulation as an additional benefit to the primary goal of reducing future thromboembolic risk. We determined the effect of carotid artery stenting on cerebral perfusion and oxygenation using a perfusion-weighted MRI algorithm that is based on assessment of capillary transit-time heterogeneity together with other perfusion and metabolism-related metrics. Patients and methods A consecutive series of 33 patients were evaluated by dynamic susceptibility contrast perfusion-weighted MRI prior to and within 24 h of the endovascular procedure. The level of relative change induced by stenting, and relationship of these changes with respect to baseline stenosis degree were analysed. Results Stenting led to significant increase in cerebral blood flow ( p < 0.001), and decrease in cerebral blood volume ( p = 0.001) and mean transit time ( p < 0.001); this was accompanied by reduction in oxygen extraction fraction ( p < 0.001) and capillary transit-time heterogeneity ( p < 0.001), but an overall increase in relative capillary transit-time heterogeneity (RTH: CTH divided by MTT; p = 0.008). No significant change was observed with respect to cerebral metabolic rate of oxygen. The median volume of tissue with MTT > 2s decreased from 24 ml to 12 ml ( p = 0.009), with CTH > 2s from 29 ml to 19 ml ( p = 0.041), and with RTH < 0.9 from 61 ml to 39 ml ( p = 0.037) following stenting. These changes were correlated with the baseline degree of stenosis. Discussion: Stenting improved the moderate stage of haemodynamic compromise at baseline in our cohort. The decreased relative transit-time heterogeneity, which increases following stenting, is probably a reflection of decreased functional capillary density secondary to chronic hypoperfusion induced by the proximal stenosis. Conclusion: Carotid artery stenting, is not only important for prophylaxis of future vascular events, but also is critical for restoration of microvascular function in the cerebral tissue.

Attempts to improve absolute quantification of cerebral blood flow in dynamic susceptibility contrast magnetic resonance imaging: a simplified T1-weighted steady-state cerebral blood volume approach

2007 ◽  
Vol 48 (5) ◽  
pp. 550-556 ◽  
Author(s):  
R. Wirestam ◽  
L. Knutsson ◽  
J. Risberg ◽  
S. Börjesson ◽  
E.-M. Larsson ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Steady State ◽  
Water Exchange ◽  
Cerebral Blood Volume ◽  
Dynamic Susceptibility ◽  
Resonance Imaging ◽  
Dynamic Susceptibility Contrast ◽  
Dsc Mri ◽  
Contrast Magnetic Resonance ◽  
Susceptibility Contrast

Background: Attempts to retrieve absolute values of cerebral blood flow (CBF) by dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) have typically resulted in overestimations. Purpose: To improve DSC-MRI CBF estimates by calibrating the DSC-MRI-based cerebral blood volume (CBV) with a corresponding T1-weighted (T1W) steady-state (ss) CBV estimate. Material and Methods: 17 volunteers were investigated by DSC-MRI and 133Xe SPECT. Steady-state CBV calculation, assuming no water exchange, was accomplished using signal values from blood and tissue, before and after contrast agent, obtained by T1W spin-echo imaging. Using steady-state and DSC-MRI CBV estimates, a calibration factor K = CBV(ss)/CBV(DSC) was obtained for each individual. Average whole-brain CBF(DSC) was calculated, and the corrected MRI-based CBF estimate was given by CBF(ss) = K×CBF(DSC). Results: Average whole-brain SPECT CBF was 40.1±6.9 ml/min·100 g, while the corresponding uncorrected DSC-MRI-based value was 69.2±13.8 ml/min·100 g. After correction with the calibration factor, a CBF(ss) of 42.7±14.0 ml/min·100 g was obtained. The linear fit to CBF(ss)-versus-CBF(SPECT) data was close to proportionality ( R = 0.52). Conclusion: Calibration by steady-state CBV reduced the population average CBF to a reasonable level, and a modest linear correlation with the reference 133Xe SPECT technique was observed. Possible explanations for the limited accuracy are, for example, large-vessel partial-volume effects, low post-contrast signal enhancement in T1W images, and water-exchange effects.

Predicting 1p/19q codeletion status using diffusion-, susceptibility-, perfusion-weighted, and conventional MRI in IDH-mutant lower-grade gliomas

2020 ◽  
pp. 028418512097362
Author(s):  
Xiefeng Yang ◽  
Yu Lin ◽  
Zhen Xing ◽  
Dejun She ◽  
Yan Su ◽  
...  
Keyword(s):  
Predictive Value ◽  
Operating Characteristic ◽  
Cerebral Blood Volume ◽  
Characteristic Curve ◽  
Lower Grade ◽  
Dynamic Susceptibility ◽  
Dynamic Susceptibility Contrast ◽  
Conventional Mri ◽  
Susceptibility Contrast ◽  
Sensitivity Specificity

Background Isocitrate dehydrogenase (IDH)-mutant lower-grade gliomas (LGGs) are further classified into two classes: with and without 1p/19q codeletion. IDH-mutant and 1p/19q codeleted LGGs have better prognosis compared with IDH-mutant and 1p/19q non-codeleted LGGs. Purpose To evaluate conventional magnetic resonance imaging (cMRI), diffusion-weighted imaging (DWI), susceptibility-weighted imaging (SWI), and dynamic susceptibility contrast perfusion-weighted imaging (DSC-PWI) for predicting 1p/19q codeletion status of IDH-mutant LGGs. Material and Methods We retrospectively reviewed cMRI, DWI, SWI, and DSC-PWI in 142 cases of IDH mutant LGGs with known 1p/19q codeletion status. Features of cMRI, relative ADC (rADC), intratumoral susceptibility signals (ITSSs), and the value of relative cerebral blood volume (rCBV) were compared between IDH-mutant LGGs with and without 1p/19q codeletion. Receiver operating characteristic curve and logistic regression were used to determine diagnostic performances. Results IDH-mutant and 1p/19q non-codeleted LGGs tended to present with the T2/FLAIR mismatch sign and distinct borders ( P < 0.001 and P = 0.038, respectively). Parameters of rADC, ITSSs, and rCBVmax were significantly different between the 1p/19q codeleted and 1p/19q non-codeleted groups ( P < 0.001, P = 0.017, and P < 0.001, respectively). A combination of cMRI, SWI, DWI, and DSC-PWI for predicting 1p/19q codeletion status in IDH-mutant LGGs resulted in a sensitivity, specificity, positive predictive value, negative predictive value, and an AUC of 80.36%, 78.57%, 83.30%, 75.00%, and 0.88, respectively. Conclusion 1p/19q codeletion status of IDH-mutant LGGs can be stratified using cMRI and advanced MRI techniques, including DWI, SWI, and DSC-PWI. A combination of cMRI, rADC, ITSSs, and rCBVmax may improve the diagnostic performance for predicting 1p/19q codeletion status.

scholarly journals Multicentre study of perfusion magnetic resonance imaging in paediatric brain tumours

2019 ◽  
Vol 21 (Supplement_4) ◽  
pp. iv10-iv10 ◽  
Author(s):  
Stephanie Withey ◽  
Lesley MacPherson ◽  
Adam Oates ◽  
Stephen Powell ◽  
Jan Novak ◽  
...  
Keyword(s):  
Contrast Agent ◽  
Brain Tumours ◽  
Cerebral Blood Volume ◽  
Perfusion Magnetic Resonance Imaging ◽  
Low Grade ◽  
Dynamic Susceptibility ◽  
High Grade ◽  
Dynamic Susceptibility Contrast ◽  
Perfusion Studies ◽  
Paediatric Brain Tumours

Abstract Studies in adults have shown that brain tumour perfusion correlates with grade. These studies are dominated by gliomas grade II to IV which are rare in children. The standard method, Dynamic Susceptibility Contrast MRI, provides estimates of relative cerebral blood volume (rCBV) but contrast agent leakage affects rCBV accuracy. The majority of perfusion studies have been conducted at single centres and variation in acquisition protocols makes the generalizability of results questionable. The aim of this study was to compare leakage-corrected rCBV with grade in paediatric brain tumours at multiple centres. Scans were analysed from 85 patients at 4 centres on 6 scanners prior to treatment. MRI protocols varied between centres. Histological diagnoses including grade were obtained. Whole-tumour median rCBV was significantly higher in the 45 high grade than the 40 low grade tumours (2.54 ± 1.63 ml/100ml vs 1.68 ± 1.36 ml/100ml, p=0.010). Low grade tumours, particularly pilocytic astrocytomas (grade I), displayed more contrast agent leakage consistent with their appearance on contrast enhanced images and required more leakage correction than high grade tumours. This finding differs from that in adults where contrast agent uptake is usually associated with higher grade. A cut-off of 1.70 ml/100ml for rCBV gave sensitivity and specificity of 76% and 65% respectively for discriminating grade. In summary, perfusion MRI can be used to help distinguish between low and high grade paediatric brain tumours. This finding is robust across multiple centres and acquisition protocols but correction should be made for leakage of contrast agent from the vessels.

scholarly journals Clinical Applications of Contrast-Enhanced Perfusion MRI Techniques in Gliomas: Recent Advances and Current Challenges

2017 ◽  
Vol 2017 ◽  
pp. 1-27 ◽  
Author(s):  
Junfeng Zhang ◽  
Heng Liu ◽  
Haipeng Tong ◽  
Sumei Wang ◽  
Yizeng Yang ◽  
...  
Keyword(s):  
Brain Tumors ◽  
Imaging Techniques ◽  
Malignant Gliomas ◽  
Response Assessment ◽  
Clinical Applications ◽  
Vascular Pathology ◽  
Molecular Characteristics ◽  
Dynamic Susceptibility ◽  
Dynamic Susceptibility Contrast ◽  
Contrast Enhanced

Gliomas possess complex and heterogeneous vasculatures with abnormal hemodynamics. Despite considerable advances in diagnostic and therapeutic techniques for improving tumor management and patient care in recent years, the prognosis of malignant gliomas remains dismal. Perfusion-weighted magnetic resonance imaging techniques that could noninvasively provide superior information on vascular functionality have attracted much attention for evaluating brain tumors. However, nonconsensus imaging protocols and postprocessing analysis among different institutions impede their integration into standard-of-care imaging in clinic. And there have been very few studies providing a comprehensive evidence-based and systematic summary. This review first outlines the status of glioma theranostics and tumor-associated vascular pathology and then presents an overview of the principles of dynamic contrast-enhanced MRI (DCE-MRI) and dynamic susceptibility contrast-MRI (DSC-MRI), with emphasis on their recent clinical applications in gliomas including tumor grading, identification of molecular characteristics, differentiation of glioma from other brain tumors, treatment response assessment, and predicting prognosis. Current challenges and future perspectives are also highlighted.

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