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

Inclusion Criteria: * Patients who have De novo glioblastoma multiforme, anaplastic astrocytoma, anaplastic oligodendrogliomas, mixed anaplastic oligoastrocytomas, gliosarcoma of the Brain, not involving the brain stem or optics chiasm, diagnosed following biopsy or tumor removal. * Age \> 18 years * Given written consent * Adequate bone marrow reserve(hemoglobin \> 10 grams, Absolute neutrophil count \> 1500 / mm3, platelets \> 100,000/ mm3) * Normal renal function(BUN \< 24 mg/dL, Creatinine \< 1.3 mg/dL) * Normal liver function(Total Bilirubin \< 1.5 mg/dL, SGPT/ALT \< 60 U/L) Exclusion Criteria: * Have a Karnofsky score of \< 60 \[Appendix B\] or age \< 18 years. * Prior chemotherapy and/or radiotherapy of their glioblastomamultiforme, anaplastic astrocytoma, anaplastic oligodendrogliomas, mixed anaplastic oligoastrocytomas, gliosarcoma. * Tumors located in the brainstem or optic chiasm. * Prior radiation therapy to the brain * Prior chemotherapy within the past 6 weeks.