Low Dose Radiation Therapy for Glioblastoma Multiforme

All patients will receive 0.5 Gy of radiation therapy twice daily. This study will include a safety run-in component. If \> 33% of patients in the initial cohort of 6 experience grade 3 or greater hematologic toxicity according to the NCI Common Toxicity Criteria version 4, then a dose reduction will occur following the schedule listed below.

All patients will receive temozolomide (150 to 200 mg per square meter for 5 days during each 28 day cycle) for a total of 1 year or until the time of disease progression.