Using MRI scans to predict tumor margin propagation in GBM under immunotherapy

Rafael R Bravo

Moffitt Cancer Center

"Using MRI scans to predict tumor margin propagation in GBM under immunotherapy"

An active area of GBM research is identifying how properties of the brain tissue around the tumor as detected by MRI impact tumor growth and treatment response. Such information could be useful in determining surgical margins and optimizing patient specific treatment selection. To answer this question, we developed a tumor margin propagating algorithm in which the margin growth or shrinking rate can be locally accelerated or slowed according to T1, T1-post, T2, ADC, and FLAIR scan values. We measured how well the growing/shrinking tumor margin starting from a patient scan overlaps with the tumor margin from the subsequent patient scan with these local rate adjustments. We applied this approach to MRI sequences from 32 patients treated with hypofractionated stereotactic radiotherapy, bevacizumab and pembrolizumab at Moffitt Cancer Center. We found that the tumors tend have affinity for high-FLAIR regions in most cases, and that tumors that are growing tend to have affinity for high-T1 regions, and tumors that are shrinking tend to avoid high-T1 regions. Once our findings from this project are fully developed, they may assist future modeling efforts to predict tumor proliferation and response to immunotherapy in GBM.
Additional authors: Harshan Ravi (MD Anderson Cancer Center); Jefferey West (Moffitt Cancer Center); Mark Robertson-Tessi (Moffitt Cancer Center); Raghunand Natarajan (Moffitt Cancer Center); Robert Gatenby (Moffitt Cancer Center); Alexander Anderson (Moffitt Cancer Center)

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