PATIENT CHARACTERISTICS: Age: Under 22 Performance status: Not specified Hematopoietic: See Disease Characteristics Hepatic: Bilirubin no greater than 1.5 times normal AST or ALT less than 4.0 times normal Renal: Creatinine no greater than 1.5 times normal OR Creatinine clearance or GFR greater than 70 mL/min per 1.73 square meters or GFR in equivalent institutional normal range Cardiovascular: Shortening fraction greater than 27% by echocardiogram or in institutional normal range OR Ejection fraction greater than 47% by radionuclide angiogram