Bevacizumab and carboplatin increase survival and asymptomatic tumor volume in a glioma model

To evaluate effcacy and MRI fndings after intravenous bevacizumab and/or carboplatin in a human glioma animal model, we randomized male nude rats with intracerebral UW28 human glioma xenografts to four groups: (1) controls (n 5 9), (2) bevacizumab 10 mg/kg (n 5 6), (3) carboplatin 200 mg/m² (n 5 6), and (4) bevacizumab 1 carboplatin (n 5 6). MRI was performed on the day of treatment (day 7-10) and 1 week later, and rats were followed for survival. Dynamic MRI was done in three controls and three rats treated with bevacizumab with or without carboplatin before and 24 h after treatment. Median overall survival (OS) was as follows: group 1, 16 days; group 2, 23 days; group 3, 22 days; group 4, 36 days. OS was signifcantly longer in group 4 than in group 1 (p 5 0.0011), group 2 (p 5 0.0014), and group 3 (p 5 0.0015), and rats had signifcantly larger tumors. No objective tumor responses were observed on MR images at 1 week after treatment; however, after bevacizumab, dynamic MRI showed reduced gadolinium enhancement intensity and increased time to peak, consistent with