PATIENT CHARACTERISTICS: Age: Under 18 Performance status: WHO 0-2 Play-performance scale at least 60% Life expectancy: Not specified Hematopoietic: Not specified Hepatic: Bilirubin less than 2.5 times normal Renal: Creatinine less than 2.5 times normal Cardiovascular: No symptoms of cardiac failure No decline of ejection fraction by more than 20% of the lower limit of normal Shortening fraction at least 25% Other: No psychological, familial, sociological or geographical condition that would hamper compliance No uncontrolled infection