Temozolomide and Radiation Therapy in Treating Patients With Newly Diagnosed Glioblastoma Multiforme or Anaplastic Astrocytoma

OBJECTIVES: Primary * To determine the maximum tolerated dose of temozolomide when given in combination with hypofractionated intensity-modulated conformal stereotactic radiotherapy in patients with newly diagnosed de novo glioblastoma multiforme or anaplastic astrocytoma. Secondary * To determine the time to neuroradiological evidence of tumor recurrence or progression in patients treated with this regimen. * To determine the survival time of patients treated with this regimen. * To determine the time spent in a Karnofsky performance status of 60-100%. OUTLINE: This is a dose-escalation study of temozolomide. Beginning 1-3 weeks following surgery or biopsy, patients receive oral temozolomide once daily for 5 weeks. Beginning 1 week after starting temozolomide, patients also undergo hypofractionated intensity-modulated conformal stereotactic radiotherapy once daily 5 days a week for 3 weeks. After completion of study treatment, patients are followed at 1 month, 2 months, and 3 months, and then every 3 months thereafter.