10220-ni-9 prediction of an effect of eliminating high intensity areas on flair imaging after one-shot bevacizumab for glioblastoma

Abstract PURPOSE Bevacizumab (BEV) demonstrates an affect of alleviating high intensity areas (HIA) on FLAIR imaging in glioblastoma, although it shows differences between patients. We investigated prediction factors of alleviating HIA after one-shot BEV. METHODS Twenty patients with glioblastoma enrolled in this study. MRI including arterial spin labeling (ASL) were performed before and after administrating BEV (one-shot at 10 mg/kg). From eliminating volume of HIA on FLAIR between before and after BEV, we assessed the eliminating rates (1-pre-volume/post-volume%). All patients were divided into two groups, either less or more than the mean of the eliminating rate. We compared results of plausible factors before BEV, including HIA volume, enhancing volume on T1WI with contrast media, tumor locations, presence of central necrosis, and CBF T/N on ASL, between two groups. RESULTS The mean of the eliminating rate of HIA volume on FLAIR between before and after BEV was 40.7%. Between two groups less than and more than eliminating rate of 40.7%. only CBF T/N at a large region of interest surrounding entire tumor showed a significant difference, which patients with larger eliminating rate showed smaller CBF T/N. CONCLUSION The results in this study suggested a possibility that CBF T/N on ASL is a predction factor of alleviating HIA after one-shot BEV. CBF T/N on ASL has been reported to correlates to the amount of expression of VEGF. In patients with smaller CBF T/N, the VEGF-neutralizing effect from one-shot BEV is likely to be relatively high.