This randomized phase II trial studies how well bevacizumab with or without radiation therapy works in treating patients with recurrent glioblastoma. Monoclonal antibodies, such as bevacizumab, can block tumor growth in different ways. Some block the ability of tumor cells to grow and spread. Others find tumor cells and help kill them or carry cancer-killing substances to them. Specialized radiation therapy that delivers a high dose of radiation directly to the tumor may kill more tumor cells and cause less damage to normal tissue. It is not yet know whether bevacizumab is more effective with or without radiation therapy in treating patients with recurrent glioblastoma