Multi-Parametric Imaging of Tumor Treatment Response to VEGF Blockade

Benjamin A. Hoff¹, Mahaveer S. Bhojani², Alnawaz Rehemtulla², Brian D. Ross¹, Craig J. Galban¹

This study investigates permeability and diffusion-weighted imaging as surrogate biomarkers of tumor response to anti-angiogenic therapy. Vascular permeability, and plasma volume fractions and apparent diffusion coefficient (ADC) maps were acquired pre and post treatment initiation of VEGF-Trap, an anti-angiogenic agent, or vehicle in a rodent glioma model. Permeability parameters dropped significantly following treatment, whereas ADC, an indirect measure of cellularity, remained unchanged. Confirmed by histology, tumor cellularity were consistent between groups, whereas, vascular disruption was visible in treated animals resulting in a drop in cell proliferation as determined by ki-67.