Inclusion Criteria

DISEASE CHARACTERISTICS: Histologically proven recurrent glioblastoma or anaplastic
astrocytoma Stereotactically accessible, enhancing mass no greater than 50 mL total volume
by MRI No significant mass effect Recent craniotomy allowed No anaplastic
oligodendroglioma No tumors of the brainstem, cerebellum, or both hemispheres No diffuse
subependymal or CSF disease If on stable or increasing dose of steroid, must have evidence
of increasing contrast enhancement by MRI or CT scan Prior external beam radiotherapy
required

PATIENT CHARACTERISTICS: Age: Over 18 Performance status: Karnofsky 60-100% Life
expectancy: Not specified Hematopoietic: Absolute neutrophil count greater than 1500/mm3
Platelet count greater than 100,000/mm3 Hemoglobin greater than 9.5 g/dL Hepatic:
Bilirubin less than 2 mg/dL AST and ALT less than 2 times upper limit of normal (ULN)
PT/PTT no greater than ULN Renal: Creatinine less than 2 mg/dL Other: Not pregnant
Negative pregnancy test Fertile patients must use effective contraception No systemic
diseases to cause unacceptable anesthetic/operative risk No active infection requiring
treatment No unexplained febrile illness

PRIOR CONCURRENT THERAPY: Biologic therapy: No concurrent blood or platelet transfusions
Chemotherapy: At least 4 weeks since prior chemotherapy Endocrine therapy: See Disease
Characteristics Radiotherapy: See Disease Characteristics At least 4 weeks since prior
radiotherapy Surgery: See Disease Characteristics Medically able to undergo surgery Other:
No other concurrent investigational agents