QUANTITATIVE MRI OF GLIOBLASTOMA RESPONSEBruce Rosen, MD, PhD

Athinoula A. Martinos Center for Biomedical Imaging, MGH

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Future Plans/UpcomingTrials

Reproducibility of MR parameters in tumors

Improving resolution through advances in acquisition and image processing

Two-fold slice acceleration with similar SNR allowed for a significant increase in slice coverage of the brain during DSC-MRI. The protocol achieved good

results perfusion imaging

Comparison of the FOVs in standard and SMS DSC MRI. (1) Standard DSC, (2) SMS DSC, and (3) SMS DSC after eliminating the tissues out of standard DSC FOV. B: Labels of automatically generated healthy anatomical regions overlaid on MPRAGE image.

Representative GE CBV maps generated from standard (first row) and SMS (second row) DSC images for subjects 1, 2, and 3 (from left to right).

Vessel Architecture Imaging (VAI)

Vessel architectural imaging in a healthy volunteer. (a–d) Simultaneously acquired gradient-echo (GE) (a) and spin-echo (SE) (b) contrast enhanced relaxation rate images (c) in slow-inflow areas the spin-echo signal peaks earlier than the gradient-echo signal, resulting in a counterclockwise vortex (d). The contrast agent–induced relaxation rates in c and d are scaled relative to their baseline rates and will change with mean transit time.

VAI during anti-angiogenic therapy (a) anatomical MRI and VAI of a subject with recurrent glioblastoma at baseline (day −1)and at day 28 after therapy onset. (b) Vessel architecture in tumor edge, tumor center and reference tissue at baseline and day 28.

(c) KM survival curves show prolonged survival for responding subjects compared to nonresponding subjects (relative decrease in voxels with a clockwise vessel vortex direction.)

Preliminary multimodal analysis of vasogenic edema in GBM patients treated with anti-angiogenic therapy suggests distance from T1-Gd a good predictor tumor

boundary

Response to anti-angiogenic therapy for 2 patients. The VE corresponds to the responsive voxels (blue). The non responsive voxels are tumor related (red).

Radiotherapy plans for two different patients. CTV1 (blue) and CTV2 (green) are overlaid on the T2 FLAIR image. The dose distributions based on CTV1 and CTV2 are overlaid on the CT image

“Upsampling” algorithms improves resolution of DCE imaging by incorporating high resolution anatomical scan

Upsampling of BrainWeb T2W images with 5 mm slice thickness. First row: upsampling using NN, spline, and SSIP methods. Second row: upsampling using the proposed method, original HR T2W image, and HR T1W image used for upsampling.

DCE-MRI upsampling. Columns 1 to 3: images before and after upsampling, and the original image, showing time points 10 (first row, before contrast arrival) and 100 (second row, after contrast arrival). Columns 4 to 6: parametric maps (ktrans, first row; AUC, second row) from images before and after upsampling and the original image

Phase II clinical trial of TivozanibAvastin in combination with daily

temozolomide chemotherapy to look at tumor drug delivery

Phase II trial of patient specific tumor vaccination

Tumor perfusion and oxygenation

Clinical Applications of new models of Dynamic Susceptibility Contrast MRI

Scatter and Bland-Altman plots of GE CBV (SMS vs. standard)

Machine Learning based tissue classification for adaptive radiation

therapy treatment planning

Available MRI modalitiesused to define features.

Prediction for4 methods,one patient per panel. The tumor infiltration inred, the VE in blue, prediction inin white.

Our double baseline scans indicate that DWI, DSC and DCE produce biomarkers with high reproducibility within the tumor :Data will be shared in TCIADSC - CBFDSC - CBF DCE - KDCE - Ktranstrans

DWI - ADCDWI - ADC ICC Recommendations

DSC 0.96 Normalization

DCE 0.86 T1 mapping, R2* correction

DTI 0.942

Registration, ROI important