Inclusion Criteria

DISEASE CHARACTERISTICS:

- Must be undergoing a diagnostic/therapeutic craniotomy for biopsy/resection of
recurrent or newly diagnosed (or presumed) cerebral anaplastic astrocytoma or
glioblastoma multiforme

- Patients undergoing stereotactic biopsy or partial resection are eligible

PATIENT CHARACTERISTICS:

Age:

- 18 and over

Performance status:

- SWOG 0-2 OR

- Karnofsky 60-100%

Hematopoietic:

- WBC at least 3,500/mm3

- Absolute neutrophil count at least 1,800/mm3

- Platelet count at least 125,000/mm3

- Hemoglobin at least 9 g/dL

Hepatic:

- Bilirubin less than 1.5 mg/dL

- SGOT less than 2 times upper limit of normal

Renal:

- Creatinine less than 1.5 mg/dL OR

- Creatinine clearance greater than 70 mL/min

Cardiovascular:

- No cardiovascular illnesses that cannot be adequately controlled with

- appropriate therapy or would increase risk, e.g.:

- Severe cardiac disease such as uncontrolled arrhythmias or conduction

- defects

- Major problems with edema (e.g., residual leg swelling from deep venous

- thrombosis)

- Recent coronary artery disease

- Poorly controlled hypertension (systolic pressure greater than 180 mm Hg,

- diastolic pressure greater than 110 mm Hg)

Other:

- No other medical illnesses that cannot be adequately controlled with

- appropriate therapy or would increase risk, e.g.:

- Major problems with edema (e.g., Cushing's syndrome)

- Major psychiatric illness

- No other malignancy requiring active therapy

- Not pregnant or nursing

- Fertile patients must us effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- Not specified

Chemotherapy:

- Must have failed or received no prior treatment with a nitrosourea,

- procarbazine, or temozolomide

- No prior O6-benzylguanine

- At least 4 weeks since prior chemotherapy and recovered

Endocrine therapy:

- Not specified

Radiotherapy:

- At least 6 weeks since prior radiotherapy

- No prior radiotherapy to greater than 10-20% of bone marrow

Other:

- No concurrent therapy for any other malignancy

- At least 2 weeks since other prior investigational drug