DISEASE CHARACTERISTICS:

• Histologically confirmed intracranial malignant glioma

  • Original low-grade glioma histology allowed provided there is subsequent histologic confirmation of malignant glioma

• Any of the following diagnoses:

  • Glioblastoma multiforme
  • Gliosarcoma
  • Anaplastic astrocytoma
  • Anaplastic oligodendroglioma
  • Anaplastic mixed oligoastrocytoma
  • Malignant astrocytoma not otherwise specified

• Recurrent disease

  • Must have failed prior radiotherapy

    • Must have confirmation of true progressive disease (rather than radiation necrosis) based upon either positron emission tomography or thallium scanning, MR spectroscopy, or surgical documentation of disease if radiographic recurrence is within the high-dose radiation field (for patients who underwent prior interstitial brachytherapy or stereotactic radiosurgery)

• Prior recent resection of recurrent or progressive tumors allowed if all of the following criteria are met:

  • Recovered from prior surgery
  • Evaluable disease after resection

• Unequivocal evidence of tumor progression by MRI

  • Steroid dose must be stable for ≥ 5 days prior to MRI

PATIENT CHARACTERISTICS:

• Karnofsky performance status 60-100%
• Life expectancy > 8 weeks
• WBC ≥ 3,000/mm³
• Absolute neutrophil count ≥ 1,500/mm³
• Platelet count ≥ 100,000/mm³
• Hemoglobin ≥ 10 g/dL (transfusion allowed)
• AST < 2.5 times upper limit of normal (ULN)
• Bilirubin < 2.5 times ULN
• Creatinine < 1.5 mg/dL OR creatinine clearance ≥ 60 mL/min
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during and for 1 month after completion of study treatment
• No significant medical illness that would preclude study treatment
• No history of other cancer (except nonmelanoma skin cancer or carcinoma in situ of the cervix) unless disease is in complete remission and off all therapy for ≥ 1 year
• No active infection or serious intercurrent medical illness
• No disease that will obscure toxicity or dangerously alter drug metabolism
• Able to undergo MRI scan and receive contrast agents for perfusion scanning

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• Recovered from prior therapy
• At least 28 days since prior cytotoxic therapy
• At least 14 days since prior vincristine
• At least 42 days since prior nitrosoureas
• At least 21 days since prior procarbazine
• At least 7 days since prior interferon, tamoxifen, thalidomide, isotretinoin, or other noncytotoxic agents (radiosensitizer does not count)
• At least 14 days since prior noncytotoxic investigational agents
• At least 42 days since prior radiotherapy
• No prior cisplatin, carboplatin, oxaliplatin, or platinum-containing analogue
• No concurrent prophylactic filgrastim (G-CSF) or sargramostim (GM-CSF)
• No other concurrent anticancer therapy (including chemotherapy, radiotherapy, hormonal therapy, or immunotherapy)
• No other concurrent investigational drugs