DISEASE CHARACTERISTICS:

• Histologically proven recurrent or refractory pediatric solid tumor
• Bone marrow metastases allowed

PATIENT CHARACTERISTICS:

Age:

• 1 to 30

Performance status:

• 0-2

Life expectancy:

• At least 2 months

Hematopoietic:

• Absolute neutrophil count at least 1,000/mm3
• Platelet count at least 100,000/mm3 (transfusion independent)
• Hemoglobin at least 10 g/dL (RBC transfusion allowed)

Hepatic:

• Bilirubin no greater than 1.5 times normal
• SGOT no greater than 2.5 times normal

Renal:

• Adequate renal function as defined by one of the following:

  • GFR by creatinine clearance
  • Radioisotope GFR
  • Iothalamate at least 70 mL/min

Cardiovascular:

• Adequate cardiac function as defined by one of the following:

  • Ejection fraction at least 55% by MUGA
  • Fractional shortening at least 28% by echocardiogram

Neurologic:

• Adequate CNS function as defined by:

  • Seizure disorder, if present, controlled by anticonvulsants
  • CNS toxicity no greater than grade 2

Other:

• No uncontrolled infections
• Not pregnant or nursing
• No allergy to platinum compounds
• No history of allergy to etoposide (unless mobilization phase not required)

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Recovered from prior immunotherapy
• At least 1 week since prior cytokines
• At least 3 months since prior bone marrow or peripheral blood stem cell transplantation
• No concurrent immunomodulator
• No concurrent cytokines

Chemotherapy:

• At least 3 weeks (6 for nitrosourea) since prior chemotherapy and recovered
• No prior thiotepa
• No other concurrent chemotherapy

Endocrine therapy:

• Not specified

Radiotherapy:

• Recovered from prior radiotherapy
• At least 6 months since prior total body irradiation conditioning
• No concurrent radiotherapy to greater than 10% of total liver, lung, or bone marrow

Surgery:

• Not specified