- Determine the 2-year event-free survival (EFS) and overall survival (OS) of pediatric patients with previously untreated nondisseminated medulloblastoma (< 4 years of age), disseminated medulloblastoma (< 10 years of age), or noncerebellar primitive neuroectodermal tumors (PNET) (disseminated or non-disseminated) treated with induction chemotherapy followed by consolidation with myeloablative chemotherapy and autologous hematopoietic stem cell rescue.