OBJECTIVES: I. Estimate the maximum tolerated dose of total bone marrow irradiation (TMI) that can be administered as planned consolidation utilizing autologous peripheral blood stem cell support following local radiotherapy (if indicated) and prior busulfan, melphalan, and thiotepa. II. Examine the efficacy of this dual transplant approach for high-risk patients with Ewing's sarcoma, peripheral primitive neuroectodermal tumor, or rhabdomyosarcoma in first complete remission or greater.