Abstract
INTRODUCTION: Glioblastoma (GB) is the most common primary brain tumor in adults having an overall survival (OS) ranging from 12–14 months. GB is highly vascularized, partly due to excessive levels of VEGF. Recurrence is the rule in GB, the second line of treatment is antiangiogenics of which Bevacizumab(BVZ) - a humanized monoclonal antibody to the VEGF-A - is the most commonly used antiangiogenic agent in the setting of recurrent glioblastoma (rGB). rCBV has been evaluated as a predictor of response to this therapy using perfusion-weighted MR techniques. METHODS: Patients with rGB according to RANO criteria treated with BVZ with an MRI perfusion with rCBV prior treatment initiation were enrolled. The correlation between rCBV and response was analyzed by correlation coefficient. A cutoff point to identify responders and non-responders to BVZ was determined by ROC curve and OS was evaluated using Kaplan Meier curve and log rank. RESULTS: 31 patients with GB were included. We divided the patients in non-responders (n=17) and responders (n=14), there were differences between the groups (age and KPS). The correlation between the RCBV and the Therapeutic response was r=-0.83, p0.0001 (95% CI -0.918 to -0.675). The ROC curve showed 3.7 as the cutoff value with a sensitivity of 100% and specificity of 94% to predict response to BVZ. We divided the groups into non-responders and responders, with OS of 7.7 months vs 14.4 months respectively, p 0.045 (HR 2.3, 95% CI 1.0192 to 5.6192). CONCLUSIONS: rCBV is a potential biomarker evaluated by MRI that predicts response to treatment in patients who will be treated with Bevacizumab. Bevacizumab treatment is highly cost-effective, and this biomarker would help identify patients that would benefit. This biomarker as predictive/prognostic has been widely used and is currently the most reliable parameter for measuring the response to antiangiogenic treatment.