Chemotherapy Followed by Peripheral Stem Cell Transplantation in Treating Children With Newly Diagnosed Brain Tumor

DISEASE CHARACTERISTICS: * Histologically confirmed malignant, newly diagnosed brain tumor Regimen A: * Posterior fossa medulloblastoma/primitive neuroectodermal tumor (PNET): * All stages, under 3 years at diagnosis OR * High stage (local residual tumor postoperatively and/or neuraxis or extraneural dissemination), 3-10 years at diagnosis * Supratentorial PNET, pineoblastoma, cerebral neuroblastoma, ependymoblastoma, medulloepithelioma, medullomyoblastoma: * All stages, under 10 years at diagnosis * Brainstem PNET: * All stages, irrespective of extent of resection, under 10 years at diagnosis * Ependymoma or anaplastic ependymoma: * All stages, any location (except primary spinal cord ependymoma), under 3 years at diagnosis OR * Local residual tumor postoperatively and/or neuraxis dissemination, any location, 3-10 years at diagnosis * Supratentorial ependymoma: * All stages, irrespective of extent of resection, under 10 years at diagnosis, excluding gross totally resected (confirmed by postoperative MRI) low grade ependymoma not invading the ventricular system * Metastatic retinoblastoma: * Previously untreated (except for cryosurgery or laser surgery), under 10 years at presentation of metastatic disease * Primary atypical teratoid/rhabdoid tumors of the CNS: * Under 10 years at diagnosis * Choroid plexus carcinoma: * Incompletely resected, all sites, under 10 years at diagnosis Regimen C: * Anaplastic astrocytoma, glioblastoma multiforme, a…