Intrathecal Radioimmunotherapy, Radiation Therapy, and Chemotherapy After Surgery in Treating Patients With Medulloblastoma

INCLUSION CRITERIA: Patients must have histologic proof of medulloblastoma reviewed by the Department of Pathology at the Memorial Sloan-Kettering Cancer Center. Patients must begin study prescribed therapy within 42 days of neurosurgical resection of the tumor Age ≥ 3-years-old. Post-operative head MRI must confirm ≤ 1.5 cm2 of residual tumor is present. Head and spine MRI and lumbar CSF cytology must not show any definitive evidence of leptomeningeal dissemination (Chang stage M-0). Examinations evaluating extra-neural sites will not be mandated, but any performed for clinical indications must be free of metastatic disease. No prior RT or chemotherapy for the medulloblastoma is permitted Patients must have adequate CSF flow (defined as lack of compartmentalization) on an 111-Indium DTPA flow study. Patients must have adequate organ function as defined by: Hepatic: total bilirubin < 2.0 mg/dl, AST < 3 x the upper limit of normal. Renal: Calculated creatinine clearance or nuclear GFR ≥ 70 ml/min/1.73 m^2. The patient, or for minors, a parent or legal guardian, must give informed written consent indicating they are aware of the investigational nature of this study. EXCLUSION CRITERIA: Unable to start study prescribed therapy within 42 days of neurosurgical resection of the tumor Age less than 3 years > 1.5 cm2 residual tumor on post-operative head MRI Evidence of leptomeningeal dissemination on head or spine MRI or CSF cytology positivity Evidence of extra-neural metastases Prior radiation therapy or chemotherapy for the medulloblastoma Inadequate CSF flow on 111-Indium DTPA flow study Patients with signs or symptoms suggestive of increased intracranial pressure (headache, emesis, ocular paresis) will not be eligible until they are cleared by neurology and/or neurosurgery. Pregnancy Total bilirubin ≥ 2.0 mg/dl AST ≥ 3 x the upper limit of normal Creatinine clearance and GFR < 70 ml/min/1.73 m^2