Carmustine in Treating Patients With Recurrent Malignant Glioma

DISEASE CHARACTERISTICS: * Pathologically confirmed recurrent malignant glioma for which surgery is indicated * Unilateral, supratentorial, solitary lesion at least 1.0 cm in diameter on contrast-enhanced CT or MRI PATIENT CHARACTERISTICS: Age: * 18 and over Performance status: * Karnofsky 60-100% Life expectancy: * At least 8 weeks Hematopoietic: * WBC at least 3,500/mm\^3 * Platelet count at least 100,000/mm\^3 Hepatic: * Bilirubin, AST, ALT, and alkaline phosphatase less than 2.5 times normal Renal: * Creatinine less than 1.5 times normal * BUN less than 2.5 times normal * Protein no greater than 3 g/dL * No gross hematuria Other: * No hypersensitivity to nitrosoureas * Not pregnant * Fertile patients must use effective contraception * No concurrent life threatening disease PRIOR CONCURRENT THERAPY: Biologic therapy: * No concurrent immunotherapy during first 8 weeks of study Chemotherapy: * At least 4 weeks since chemotherapy (6 weeks since nitrosoureas) * No concurrent chemotherapy during first 8 weeks of study Endocrine therapy: * Not specified Radiotherapy: * Prior definitive external-beam radiotherapy (i.e., at least 5,000 cGy) required * No concurrent radiotherapy or brachytherapy during first 4 weeks of study Surgery: * Prior cytoreductive surgery for supratentorial brain tumor required * Biopsy alone not sufficient Other: * No concurrent investigational therapy during first 8 weeks of study