Inclusion Criteria

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