PATIENT CHARACTERISTICS: Age: Under 18 Performance status: Not specified Life expectancy: Greater than 12 weeks Hematopoietic: Grade 4 cytopenias allowed Grade 3 marrow hypoplasia allowed Hepatic: Not specified Renal: No renal dysfunction worse than grade 3 Cardiovascular: No cardiac dysfunction worse than grade 2 Pulmonary: No pulmonary dysfunction worse than grade 2 Other: No neurologic dysfunction worse than grade 2 Hearing deficit allowed