Carmustine Followed By Surgery in Treating Patients With Recurrent Supratentorial Malignant Glioma or Metastatic Brain Neoplasm

DISEASE CHARACTERISTICS: * Histologically confirmed recurrent supratentorial malignant glioma with clear evidence of progression by MRI * Glioblastoma multiforme * Anaplastic ependymoma * Anaplastic astrocytoma * Anaplastic oligodendroglioma OR * Metastatic tumor to the brain other than melanoma * Planned resection of tumor (must be first surgery for recurrent disease) * Tumor volume of each tumor component or residual tumor must be at least 4 cm3 and no greater than 33.4 cm3 * Tumor shape and surrounding structure(s) unlikely to cause an irregular distribution of the injected study drug * Tumor is spherical, spheroid, or ovoid * No tumors shaped into 3 or more components (e.g., multicentric or multilobulated) * No tumors extending into the ventricular system * Tumor has an intact stroma (i.e., tumor mass not partially incised or punctured) * Central necrosis and/or central cystic areas allowed if an enhancing rim with a thickness of more than 5 mm is present * No tumors in the following locations of the brain: * Brainstem (pons or medulla) * Midbrain (mesencephalon) * Primary sensorimotor cortex in the dominant hemisphere * Within 1.5 cm of the optic chiasm, either optic nerve, or any other cranial nerve PATIENT CHARACTERISTICS: Age: * 18 to 75 Performance status: * Karnofsky 60-100% Life expectancy: * Not specified Hematopoietic: * Absolute neutrophil count at least 1,500/mm\^3 * Platelet count at least 100,000/mm\^3 * No evidence of bleeding diathesis Hepatic: * Bilirubin no greater than 2.0 mg/dL * SGOT and SGPT no greater than 2.5 times normal Renal: * Creatinine no greater than 2.0 mg/dL OR * Creatinine clearance at least 40 mL/min OR * BUN no greater than 30 mg/dL Other: * No active uncontrolled infection * Afebrile (37.5 degrees C) unless fever due to tumor * No other unstable or severe medical condition * No complicating medical or psychiatric problem that would preclude study * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception PRIOR CONCURRENT THERAPY: Biologic therapy: * Not specified Chemotherapy: * At least 4 weeks since prior systemic chemotherapy (6 weeks for nitrosoureas, mitomycin, or Gliadel wafers) and recovered * No anti-tumor chemotherapy within 12 weeks after study drug unless tumor volume increases by more than 25% by MRI Endocrine therapy: * Not specified Radiotherapy: * At least 4 weeks since prior radiotherapy and recovered * No prior intracranial brachytherapy * No anti-tumor radiotherapy within 12 weeks after study drug unless tumor volume increases by more than 25% by MRI Surgery: * See Disease Characteristics * Prior surgery allowed * No anti-tumor surgery within 12 weeks after study drug Other: * No concurrent anticoagulants * No other concurrent investigational agents