Inclusion Criteria

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 at least 60%

Hematopoietic:

- Hematocrit greater than 29%

- ANC greater than 1,500/mm^3

- Platelet count greater than 125,000/mm^3

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

Other:

- Not pregnant

- Effective contraceptive method must be used for the duration of the study

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- Not specified

Chemotherapy:

- No prior chemotherapy within 6 weeks of study

- No prior topotecan or carmustine treatment failure

- No more than 1 prior chemotherapy regimen

Endocrine therapy:

- Patients taking corticosteroids must be on stable dose for at least 2 weeks prior to
study and the dose should not escalate over entry level

Radiotherapy:

- No prior radiotherapy within 6 weeks of study

Surgery:

- No prior surgical resection within 3 weeks of study

Other:

- No concurrent medication that may interfere with study results