H17089: Treatment of Patients with Newly Diagnosed Medulloblastoma, Supratenterorial Primitive Neuroectodermal Tumor, or Atypical Teratoid Rhabdoid Tumor (SJMB03): This study uses high dose chemotherapy and radiation combined with autologous stem cell transplantation to treat patients with medulloblastoma (and related diseases). The study will also be looking at genetic markers to look at how those markers correlate with treatment outcomes.