Relative cerebral blood volume as response predictor in the treatment of recurrent glioblastoma with anti-angiogenic therapy

Abstract

Abstract Introduction Glioblastoma is one of the most common brain tumors in adult populations, usually carrying a poor prognosis. While several studies have researched the impact of anti-angiogenic therapies, especially anti VEFG treatments in glioblastoma, few have attempted to assess its progress using imaging studies. Purpose We attempted to analyze whether cerebral blood volume (rCBV) from dynamic susceptibility-weighted contrast-enhanced MRI (DSC-MRI) could predict a response in patients with glioblastoma undergoing Bevacizumab (BVZ) treatment. Methods We performed a retrospective study evaluating patients with recurrent glioblastoma receiving anti-angiogenic therapy with BVZ between 2012 and 2017 in our institution. Patients were scheduled for routine MRI at baseline and first month follow up visits. Studies were processed for DSC-MRI, cT1 and FLAIR images, from which relative cerebral blood volume measurements were obtained. We assessed patient response using the Response Assessment in Neuro-Oncology (RANO) working group criteria and overall survival. Results 40 patients were included in the study and were classified as Bevacizumab responders and non-responders. Average rCBV before treatment was 4.5 for both groups and average rCBV was 2.5 for responders and 5.4 for non-responders. ROC curve set a cutoff point of 3.7 for rCBV predictive of response to BVZ. Cox Multivariate analysis only showed rCBV as a predictive factor of OS. Conclusion A statistically significant difference was found in rCBV between patients who responded and those who did not respond to BVZ treatment. rCBV may be a low cost and effective marker to assess response to Bevacizumab treatment in GBM.