PATIENT CHARACTERISTICS: Age: 3 to 21 Performance status: Karnofsky or Lansky 50-100% Life expectancy: Not specified Hematopoietic: Absolute neutrophil count at least 1,000/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin less than 2.0 mg/dL ALT no greater than 5 times upper limit of normal Renal: Creatinine or GFR normal for age