High-Dose Melphalan, Total-Body Irradiation, and Peripheral Stem Cell Transplantation in Treating Patients With Multiple Myeloma in First Relapse

DISEASE CHARACTERISTICS: Multiple myeloma confirmed by bone marrow plasmacytosis and with measurable M-component in the serum or urine by immunoelectrophoresis or immunofixation No Stage I myeloma No smoldering multiple myeloma Refractory to or in first relapse following an initial response to VAD (vincristine/doxorubicin/dexamethasone), with relapse defined as any of the following: 50% increase above the lowest remission level of serum or urine M-protein while on therapy 25-50% increase above the lowest remission level of serum or urine M-protein associated with either: Hypercalcemia (greater than 11 mg/dl) Hb decrease of 2 g/dl attributable to increasing marrow plasmacytosis Appearance of new lytic lesions Calcium no greater than 11 mg/dl No myeloma meningitis No plasma cell leukemia

PATIENT CHARACTERISTICS: Age: 18 to 65 Performance status: ECOG 0-2 Hematopoietic: WBC greater than 500 (after G-CSF) Platelets greater than 25,000 Hepatic: Bilirubin no greater than 2.0 mg/dl Renal: Creatinine no greater than 2.0 mg/dl Cardiovascular: No NYHA class II-IV disease Pulmonary: DLCO at least 50% of predicted FVC at least 75% of predicted FEV1 at least 60% of predicted Other: No uncontrolled infection No active fungal infection No fever No prior malignancy within 5 years except: Basal cell skin cancer In situ carcinoma of the cervix No pregnant or nursing women

PRIOR CONCURRENT THERAPY: Biologic therapy: Prior biological response modifiers allowed Chemotherapy: No time limit between cytotoxic therapy and protocol treatment Prior cumulative melphalan dose less than 300 mg Endocrine therapy: Corticosteroids for hypercalcemia allowed Radiotherapy: Prior radiotherapy allowed Prior pelvic radiotherapy allowed, but patients with such therapy are unlikely to have adequate PBSC harvested Surgery: Not specified