Post-radiation treatment Two to four weeks after completing radiation you will have a brain MRI scan. Beginning four weeks after radiation ends, the study drug and temozolomide will begin. The study drug (Avastin) will be administered by IV infusion (through a vein) every 2 weeks. Temozolomide will be taken orally for five consecutive days of every 28 days. In other words, you will receive two intravenous infusions of Avastin and five days of temozolomide every 28 days. This constitutes a treatment cycle. These cycles will continue indefinitely. The dose of Avastin will be based upon your weight during screening and will remain the same throughout the study. The temozolomide dose during radiation will be based on your height and weight at screening. During the study phase, temozolomide will be dosed according to your height and weight at the beginning of each treatment cycle. The dose may be delayed for up to four weeks if your blood counts are low. If temozolomide still cannot be given because your blood counts are low for longer than four weeks, the temozolomide will be stopped but the Avastin may still be continued.