Holmium Ho 166 DOTMP Followed by Peripheral Stem Cell Transplantation in Treating Patients With Metastatic Ewing's Sarcoma or Rhabdomyosarcoma That Has Spread to the Bone

DISEASE CHARACTERISTICS: Histologically confirmed Ewing's sarcoma family of tumors or rhabdomyosarcoma with bone metastases Refractory to conventional therapy OR Responsive to conventional therapy with osseous metastases at diagnosis that are extensive enough to preclude concurrent radiotherapy to all sites Soft tissue, pulmonary, and/or bone marrow metastases in addition to cortical bone allowed Extraosseous sites of disease allowed if amenable to surgical resection or external beam radiotherapy No patients under 10 years old with embryonal rhabdomyosarcoma Adequate peripheral blood stem cells stored At least 2,500,000 CD34+ cells/kg No impending bone fracture or spinal cord compression PATIENT CHARACTERISTICS: Age: 12 and over Performance status: 0-2 Life expectancy: At least 2 months Hematopoietic: Absolute neutrophil count at least 1,000/mm^3 Platelet count at least 75,000/mm^3 (transfusion independent) Hemoglobin at least 10.0 g/dL (RBC transfusion allowed) Hepatic: Bilirubin no greater than 1.5 times normal SGOT no greater than 2.5 times normal Renal: Radioisotope glomerular filtration rate, iothalamate clearance, or creatinine clearance at least 60 mL/min Other: No uncontrolled infection Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception PRIOR CONCURRENT THERAPY: Biologic therapy: Recovered from prior immunotherapy At least 3 months since prior bone marrow or peripheral blood stem cell transplantation (6 months for total body irradiation conditioning) and recovered At least 1 week since prior cytokines No immunomodulators during and for at least 4 weeks after study No concurrent cytokines Chemotherapy: At least 3 weeks since prior chemotherapy (6 weeks for nitrosoureas) and recovered No more than 3 prior systemic chemotherapy regimens No systemic chemotherapy during and for at least 4 weeks after study Endocrine therapy: Not specified Radiotherapy: See Disease Characteristics See Biologic therapy Recovered from prior radiotherapy No prior maximum tolerable radiotherapy (greater than 30 Gy) to the spinal cord No prior therapeutic doses of bone-seeking radiopharmaceutical (e.g., samarium Sa 153 lexidronam pentasodium EDTMP) No radiotherapy during and for at least 4 weeks after study Local radiotherapy to any tumor site allowed provided at least 1 evaluable lesion is untreated Surgery: See Disease Characteristics No surgical resection of all bone metastases evaluable by PET during and for 1 month after study Other: At least 4 weeks since prior bisphosphonates