Whole-Body Radiation Therapy, Systemic Chemotherapy, and High-Dose Chemotherapy Followed By Stem Cell Rescue in Treating Patients With Poor-Risk Ewing Sarcoma

adult supratentorial primitive neuroectodermal tumor (pnet), ewing sarcoma of bone, extraosseous ewing sarcoma, metastatic ewing sarcoma/peripheral primitive neuroectodermal tumor, recurrent childhood supratentorial primitive neuroectodermal tumor, recurrent ewing sarcoma/peripheral primitive neuroectodermal tumor, untreated childhood supratentorial primitive neuroectodermal tumor, interventional, na