Radiation Therapy in Treating Patients With Recurrent Brain Tumors Who Have Undergone Previous Radiation Therapy

PRIMARY OBJECTIVES: I. To estimate the rate of grade 3 or higher central nervous system (CNS) necrosis 6 months after reirradiation of the brain for recurrent tumor. SECONDARY OBJECTIVES: I. To evaluate acute and late toxicities of reirradiation. II. To evaluate longitudinal changes in symptom burden of patients undergoing reirradiation. III. To use Advanced Brain Tumor Imaging (ABTI) to evaluate changes in the brain after reirradiation, including progression, pseudoprogression, and radionecrosis. IV. To estimate progression-free survival (PFS) and overall survival (OS) following reirradiation. OUTLINE: Patients are assigned to 1 of 2 arms based on age. ARM I (Age 0-18 years): Patients undergo radiation therapy with conventional fractionation and dose constraints. Treatment continues for up to 6 weeks in the absence of disease progression or unacceptable toxicity. ARM II (Age \> 18 years): Patients undergo radiation therapy with conventional fractionation and dose constraints. Patients also receive bevacizumab concurrently at the discretion of the treating neuro-oncologist. Treatment continues for up to 6 weeks in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up at 1 month, then every 2 months for 1 year, then every 3 months for 1 year.