DISEASE CHARACTERISTICS:

• Histologically confirmed supratentorial malignant glioma

  • Recurrent or progressive disease
• Amenable to gross total resection, clinically indicated partial resection, or biopsy

• Tumor must have a single solid portion at least 1 cm and no greater than 5 cm in maximum diameter

  • No tumor crossing midline

    • Tumors invading the corpus callosum that do not extend beyond to midline or into the contralateral hemisphere allowed
  • No more than 1 focus of tumor
  • No tumors involving the brainstem or cerebellum
  • No tumor dissemination (i.e., subependymal or leptomeningeal)
• Must be on steroids ≥ 3 days prior to surgery
• Must have received prior external beam radiotherapy (tumor dose at least 45 Gy) and completed therapy at least 8 weeks before study entry
• No impending herniation, including midline shift greater than 0.5 cm
• No requirement for immediate palliative treatment

PATIENT CHARACTERISTICS:

Age

• 3 to 21

Performance status

• Karnofsky 60-100% (patients over 16 years of age) OR
• Lansky 60-100% (patients age 16 and under)

Life expectancy

• Not specified

Hematopoietic

• Absolute neutrophil count at least 1,500/mm^3
• Platelet count at least 100,000/mm^3*
• Hemoglobin at least 9 g/dL* NOTE: *Transfusion independent

Hepatic

• ALT and AST less than 2.5 times upper limit of normal (ULN)
• PT and PTT no greater than ULN

Renal

• Creatinine less than 1.5 times normal OR
• Glomerular filtration rate greater than 70 mL/min

Other

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during and for at least 30 days after study participation
• No uncontrolled seizures
• No active infection requiring treatment
• No unexplained febrile illness
• No known or suspected allergies to local anesthetics
• No systemic disease or other condition that may be associated with unacceptable anesthetic/operative risk and/or that would preclude study completion
• No other malignancy within the past 5 years except curatively treated carcinoma in situ or basal cell skin cancer

PRIOR CONCURRENT THERAPY:

Biologic therapy

• At least 8 weeks since prior hematopoietic stem cell transplantation

Chemotherapy

• At least 6 months since prior polifeprosan 20 with carmustine implant (Gliadel® wafer)
• At least 4 weeks since prior cytotoxic chemotherapy (6 weeks for nitrosoureas and 2 weeks for vincristine)
• At least 2 weeks since prior non-cytotoxic chemotherapy
• No other prior intracerebral chemotherapy
• No concurrent chemotherapy

Endocrine therapy

• Concurrent steroids allowed

Radiotherapy

• See Disease Characteristics
• No prior focal radiotherapy (e.g., gamma knife radiosurgery, stereotactic radiosurgery, or brachytherapy)
• No concurrent radiotherapy

Surgery

• Not specified

Other

• Recovered from prior therapy
• At least 4 weeks since prior anticancer investigational agents
• No prior localized antitumor therapy for malignant glioma
• No other concurrent investigational agent
• No other concurrent anticancer (including alternative anticancer medicines/treatment) agent or therapy