Combination Chemotherapy Followed By Peripheral Stem Cell Transplant in Treating Young Patients With Newly Diagnosed Supratentorial Primitive Neuroectodermal Tumors or High-Risk Medulloblastoma

DISEASE CHARACTERISTICS:

• Diagnosis of 1 of the following:

  • High-risk medulloblastoma defined by any of the following:

    • Residual disease > 1.5 cm²
    • Lumbar cerebral spinal fluid cytology positive for tumor cells by analysis of fluid collected either before definitive surgery or ≥ 10 days after definitive surgery unless contraindicated
    • M0 disease in children < 8 months of age at diagnosis
    • M2 or M3 metastatic disease by MRI
    • M4 disease
  • Supratentorial primitive neuroectodermal tumor (PNET) (any M-stage)
  • Anaplastic medulloblastoma regardless of M-stage or residual tumor
  • M0 classic, non-desmoplastic medulloblastoma (R1) with radiographically measurable residual disease < 1.5 cm^2
• MRI evidence of spinal disease
• Tumor must be negative for INI1 gene
• Has undergone definitive surgery within the past 31 days
• No atypical teratoid rhabdoid tumors
• Biological specimens must be available for correlative laboratory studies

PATIENT CHARACTERISTICS:

• Life expectancy > 8 weeks
• Creatinine clearance or radioisotope glomerular filtration rate ≥ 60 mL/min
• Bilirubin ≤ 1.5 times upper limit of normal (ULN)
• AST and ALT < 2 times ULN
• Shortening fraction ≥ 27% by echocardiogram
• Ejection fraction ≥ 47% by radionuclide angiogram
• No evidence of dyspnea at rest
• Pulse oximetry > 94% on room air
• Absolute neutrophil count > 1,000/mm³
• Platelet count > 100,000/mm³ (transfusion independent)
• Hemoglobin > 8 g/dL (RBC transfusions allowed)

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• No prior radiation therapy or chemotherapy
• Prior corticosteroids allowed