Radiation Therapy Followed by Carmustine in Treating Patients Who Have Supratentorial Glioblastoma Multiforme

DISEASE CHARACTERISTICS: * Histologically confirmed supratentorial glioblastoma multiforme by surgical biopsy or resection within 5 weeks of study * Postoperative residual contrast enhancing tumor and resection tumor cavity together no greater than 60 mm in maximum diameter * No well-differentiated or anaplastic astrocytomas or multifocal glioma * No tumors originating in the brainstem * No residual tumor within 10 mm of optic chiasm * No recurrent glioblastoma multiforme PATIENT CHARACTERISTICS: Age: * Not specified Performance status: * Zubrod 0-1 Life expectancy: * Not specified Hematopoietic: * Hemoglobin greater than 9 g/dL * Absolute neutrophil count greater than 1,500/mm\^3 * Platelet count greater than 100,000/mm\^3 Hepatic: * Bilirubin less than 2.0 mg/dL * Serum glutamate pyruvate transaminase (SGPT) or serum glutamate oxaloacetate transaminase (SGOT) less than 2 times normal Renal: * Creatinine less than 1.8 mg/dL * Blood urea nitrogen (BUN) less than 30 mg/dL Pulmonary: * Chest x-ray normal OR * Diffusion capacity of lung for carbon monoxide (DLCO) greater than 60% predicted Other: * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * Neurologic functional status 0-3 * No other prior malignancy within the past 5 years except carcinoma in situ of the cervix or bladder, ductal carcinoma in situ of the breast, or nonmelanomatous skin cancer PRIOR CONCURRENT THERAPY: Biologic therapy: * Not specified Chemotherapy: * Not specified Endocrine therapy: * Concurrent steroids allowed Radiotherapy: * Not specified Surgery: * See Disease Characteristics Other: * Concurrent anticonvulsants allowed