Abstract #0282

Acute Effects of Bevacizumab on Glioblastoma Vascularity Assessed with DCE-MRI and Relation to Patient Survival

Weiting Zhang¹, Teri N. Kreisl¹, Jeff Solomon², Richard C. Reynolds³, Danial R. Glen³, Robert W. Cox³, Howard A. Fine¹, John A. Butman⁴

¹Neuro-Oncology Branch, National Cancer Institute, NIH, Bethesda, MD, USA; ²Medical Numerics, Inc., Germantown, MD, USA; ³National Institute of Mental Health, NIH, USA; ⁴Radiology and Imaging Sciences, Clinial Center, NIH, USA

DCE-MRI was used to monitor the acute effects of Bevacizumab on physiologic measures of tumor vascularity, such as blood brain barrier permeability, represented as Ktrans. In addition, we relate these to progression free survival (PFS) and to overall survival (OS). Bevacizumab dramatically reduces Ktrans (46%) and enhancing tumor volume (39%) in recurrent GBMs within 96-hour of a single dose. However, tumors in which Bevacizumab resulted in larger decreases in Ktrans did not demonstrate an improved survival over those with smaller reductions in Ktrans. GBMs with larger baseline enhancing tumor volume and greater baseline Ktrans both predicted poorer PFS and OS.