Inclusion Criteria

DISEASE CHARACTERISTICS: Histologically confirmed malignant glioma determined from prior
stereotactic biopsy or cytoreductive surgery for removal of a supratentorial brain tumor
Unilateral supratentorial tumor, measuring at least 1 cm, as determined by CT scan or MRI
No more than 1 focus of tumor and no tumor crossing the midline Surgical treatment
indicated at baseline evaluation Received prior definitive (greater than 5,000 cGy)
external beam radiotherapy more than 3 months ago Evidence of progression At time of tumor
resection and Gliadel wafers implantation: Intraoperative pathological diagnosis on frozen
section or squash preparation of malignant glioma OR Glioblastoma multiforme or anaplastic
astrocytoma on permanent sections from a prior surgery and an intraoperative pathological
diagnosis on frozen section or squash preparation of tumor, glioma, or malignant glioma
(not necrosis)

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 60-100% Life
expectancy: At least 60 days Hematopoietic: Absolute neutrophil count at least 1,500/mm3
Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater than 1.5 mg/dL
Transaminases no greater than 4 times upper limit of normal Renal: Creatinine no greater
than 1.7 mg/dL Other: Not pregnant or nursing Negative pregnancy test Fertile patients
must use effective contraception for 1 year after surgery No other concurrent significant
life threatening disease No known hypersensitivity to nitrosoureas No other malignancy in
past five years except curatively treated carcinoma in situ of the cervix or basal cell
carcinoma of the skin

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: At least 4 weeks
since prior chemotherapy (6 weeks for nitrosoureas) and recovered No other concurrent
chemotherapy during first 56 days of study Endocrine therapy: No concurrent dexamethasone
as an antiemetic Radiotherapy: See Disease Characteristics Surgery: See Disease
Characteristics