Dynamic-susceptibility Contrast Agent MRI Measures of Relative Cerebral Blood Volume Predict Response to Bevacizumab in Recurrent High-Grade Glioma

Neuro Oncol. 2014 Jun;16(6):880-8. doi: 10.1093/neuonc/not216. Epub 2014 Jan 15.

Abstract

Background: The anti-VEGF antibody, bevacizumab, is standard treatment for patients with recurrent glioblastoma. In this setting, traditional anatomic MRI methods such as post-contrast T1-weighted and T2-weighted imaging are proving unreliable for monitoring response. Here we evaluate the prognostic significance of pre- and posttreatment relative cerebral blood volume (rCBV) derived from dynamic susceptibility contrast MRI to predict response to bevacizumab.

Methods: Thirty-six participants with recurrent high-grade gliomas who underwent rCBV imaging 60 days before and 20-60 days after starting bevacizumab treatment were enrolled. Tumor regions of interest (ROIs) were determined from deltaT1 maps computed from the difference between standardized post and precontrast T1-weighted images. Both pre- and posttreatment rCBV maps were corrected for leakage and standardized (stdRCBV) to a consistent intensity scale. The Kaplan-Meier method was used to determine if either the pre- or post-bevacizumab stdRCBV within the tumor ROI was predictive of overall survival (OS) or progression free survival (PFS).

Results: The OS was significantly longer if either the pre- (380d vs 175d; P=.0024) or posttreatment stdRCBV (340d vs 186d; P = .0065) was <4400. The posttreatment stdRCBV was also predictive of PFS (167d vs 78d; P = .0006). When the stdRCBV values were both above versus both below threshold, the OS was significantly worse (100.5d vs 395d; P < .0001). With a 32.5% decrease in stdRCBV, the risk of death was reduced by about 68% but increased by 140% with a 29% increase in stdRCBV.

Conclusions: Standardized rCBV is predictive of OS and PFS in patients with recurrent high-grade brain tumor treated with bevacizumab.

Keywords: DSC; MRI; bevacizumab; brain tumor; perfusion; rCBV.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Angiogenesis Inhibitors / therapeutic use*
  • Antibodies, Monoclonal, Humanized / therapeutic use*
  • Bevacizumab
  • Brain Neoplasms / blood supply
  • Brain Neoplasms / drug therapy*
  • Cerebral Cortex / blood supply*
  • Contrast Media
  • Female
  • Glioblastoma / blood supply
  • Glioblastoma / drug therapy*
  • Humans
  • Image Processing, Computer-Assisted
  • Magnetic Resonance Imaging / methods*
  • Male
  • Middle Aged
  • Prognosis
  • Survival Analysis

Substances

  • Angiogenesis Inhibitors
  • Antibodies, Monoclonal, Humanized
  • Contrast Media
  • Bevacizumab