Bevacizumab in the Radiation Treatment of Recurrent Malignant Glioma

This is a pilot study. The goal of this study is to test whether Bevacizumab is safe enough in patients with brain tumors so that a larger study can be conducted. This study will also give us some information about whether the combination of Bevacizumab and radiation has potential to become an effective treatment for regrowing brain tumors. Bevacizumab is an experimental drug that blocks a molecule called VEGF that is found in high amounts in malignant gliomas. VEGF promotes the growth of blood vessels that bring nutrients to tumor cells. In studies with laboratory animals, Bevacizumab slowed the growth of several different types of human cancer cells by blocking the effects of VEGF. There is also evidence that Bevacizumab enhances the effects of radiation on tumor cell