Evaluation of Antiangiogenic Effect Using Arterial Spin Labeling Perfusion MR Imaging in Rat Glioblastoma Model Treated with Bevacizumab

Abstract

Background and Purpose– I evaluated the antiangiogenic effect of bevacizumab in a rat glioblastoma (GBM) model based on arterial spin labeling (ASL) perfusion MR imaging compared to dynamic susceptibility contrast (DSC) perfusion MR imaging with histopathology. Materials and Methods– The protocol was approved by the institutional animal care and use committee. DSC and ASL perfusion MR imaging were performed using a 9.4 T MR scanner in nude rats with GBM. Rats were randomly assigned in the following three groups: control, 3-days treatment, and 10-days treatment. One-way analysis of variances was used to compare perfusion parameters (e.g. normalized cerebral blood volume [nCBV] from DSC MR imaging, and normalized cerebral blood flow [nCBF] based on DSC MR imaging and ASL MR imaging) with microvessel area (MVA) on histology Pearsons correlations between perfusion parameters and MVA were determined. Results– MVA showed the consistent decrease with significant differences for the control, 3-days treatment, and 10-days treatment (P < 0.001). Consistent decreases with significant differences were also revealed in all perfusion parameters (P < 0.05 for all). In addition, nCBV and nCBF from DSC, and nCBF from ASL strongly correlated with MVA (R2 = 0.830, 0.755, and 0.739, respectively, P < 0.001 for all). Conclusions– nCBF based on ASL has the potential to be used to evaluate the effect of antiangiogenic therapy on GBMs treated with bevacizumab with strong correlation with MVA.