Irinotecan Plus Carmustine in Treating Patients With Recurrent Primary Malignant Glioma

DISEASE CHARACTERISTICS: Histologically proven recurrent primary malignant glioma Measurable recurrent or residual primary central nervous system neoplasm confirmed by MRI PATIENT CHARACTERISTICS: Age: 18 and over Performance Status: Karnofsky 60-100% Hematopoietic: Hematocrit greater than 29% Absolute neutrophil count greater than 1,500/mm3 Platelet count greater than 125,000/mm3 Hepatic: SGOT less than 1.5 times upper limit of normal (ULN) Bilirubin less than 1.5 times ULN Renal: Creatinine less than 1.5 mg/dL BUN less than 25 mg/dL Pulmonary: DLCO at least 60% Other: Not pregnant Fertile patients must use effective contraception PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: At least 6 weeks since prior chemotherapy No prior irinotecan or carmustine treatment failure No more than 1 prior chemotherapy regimen Endocrine therapy: Patients taking corticosteroids must be on a stable dose for at least 1 week prior to study and the dose should not escalate over entry dose level Radiotherapy: At least 6 weeks since prior radiotherapy Surgery: At least 3 weeks since prior surgical resection Other: No concurrent medication that may interfere with study results