Oxaliplatin in Treating Children With Recurrent or Refractory Medulloblastoma, Supratentorial Primitive Neuroectodermal Tumor, or Atypical Teratoid Rhabdoid Tumor

DISEASE CHARACTERISTICS: Histologically confirmed medulloblastoma, supratentorial primitive neuroectodermal tumor (including pineoblastomas and ependymoblastomas), or atypical teratoid rhabdoid tumor Recurrent or refractory disease Measurable disease by radiography Patients with positive cerebrospinal fluid cytology or linear leptomeningeal disease are eligible PATIENT CHARACTERISTICS: Age 21 and under Performance status Karnofsky 50-100% OR Lansky 50-100% Life expectancy Not specified Hematopoietic Absolute neutrophil count at least 1,000/mm^3 Platelet count at least 100,000/mm^3 (transfusion independent) Hemoglobin at least 8.0 g/dL (RBC transfusions allowed) Hepatic Bilirubin no greater than 1.5 times normal ALT less than 2.5 times normal Renal Creatinine no greater than 1.5 times normal OR Creatinine clearance or radioisotope glomerular filtration rate at least 70 mL/min Cardiovascular Shortening fraction at least 27% by echocardiogram OR Ejection fraction at least 50% by MUGA Pulmonary No dyspnea at rest No exercise intolerance Pulse oximetry greater than 94% Other No uncontrolled infection No active graft-versus-host disease No uncontrolled seizure disorders Seizure disorders well controlled with anticonvulsants allowed Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception PRIOR CONCURRENT THERAPY: Biologic therapy At least 2 weeks since prior growth factors At least 6 months since prior allogeneic stem cell transplantation No concurrent colony-stimulating factors during the first course of study No concurrent immunomodulating agents Chemotherapy At least 3 weeks since prior myelosuppressive therapy (6 weeks for nitrosoureas) and recovered No other concurrent anticancer chemotherapy Endocrine therapy If concurrent corticosteroids necessary for intracranial pressure, must be on stable or decreasing dose for at least 1 week prior to study No other concurrent corticosteroids Radiotherapy At least 2 weeks since prior local palliative radiotherapy (small port) to symptomatic metastatic sites At least 3 months since prior craniospinal radiotherapy No concurrent palliative radiotherapy Recovered from prior radiotherapy Surgery Not specified Other No other concurrent anticancer or experimental drugs