• Event-free survival rate at 1 year [ Designated as safety issue: No ]
  

• Feasibility and safety [ Designated as safety issue: Yes ]
  
• Toxicity [ Designated as safety issue: Yes ]
  
• Neuropsychological and neuroendocrine effects [ Designated as safety issue: No ]
  
• Incidence of atypical teratoid and/or rhabdoid tumor [ Designated as safety issue: No ]
  

OBJECTIVES:

• Compare the efficacy of cyclophosphamide, vincristine, cisplatin, and etoposide followed by second-look surgery and focal conformal radiotherapy vs combination therapy administered on POG 9233 in terms of event-free survival rates in children with nonmetastatic medulloblastoma or posterior fossa primitive neuroectodermal tumor.
• Assess the feasibility and safety of this treatment regimen in these patients.
• Determine the acute and chronic toxicities of this regimen in these patients.
• Determine the neuropsychological and neuroendocrine effects of this regimen in these patients.
• Determine the incidence of atypical teratoid/rhabdoid tumor in these patients.

OUTLINE: This is a multicenter study.

Patients receive induction chemotherapy consisting of vincristine IV on days 1, 8, and 15; cisplatin IV over 6 hours on day 1; cyclophosphamide IV over 30 minutes on day 2; and oral etoposide daily on days 2-22. Treatment repeats every 28 days for a total of 4 courses.

After completion of induction chemotherapy, patients with residual disease undergo a second resection.

Within 4 weeks after completion of induction chemotherapy or second resection, patients receive focal conformal radiotherapy daily, 5 days a week, for 6 weeks.

Four weeks after completion of radiotherapy, patients receive alternating treatments of maintenance chemotherapy. Patients receive vincristine IV on days 1, 8, and 15 and cyclophosphamide IV over 30 minutes on day 1 of courses 1, 3, 5, and 7 and oral etoposide daily on days 1-21 of courses 2, 4, 6, and 8. Treatment continues every 28 days for 8 courses.

Patients are followed every 3 months for 1 year, every 4 months for 1 year, every 6 months for 1 year, and then annually thereafter.

PROJECTED ACCRUAL: A total of 65 patients will be accrued for this study.

DISEASE CHARACTERISTICS:

• Histologically confirmed primary medulloblastoma or posterior fossa primitive neuroectodermal tumor

  • Prior definitive tumor resection within 6 weeks of study
• No evidence of metastases

PATIENT CHARACTERISTICS:

Age:

• 8 months to 3 years

Performance status:

• Not specified

Life expectancy:

• Not specified

Hematopoietic:

• Hemoglobin at least 10 g/dL
• Absolute neutrophil count at least 1,500/mm3
• Platelet count at least 100,000/mm3

Hepatic:

• AST less than 2.5 times normal
• Bilirubin less than 1.5 mg/dL

Renal:

• Creatinine less than 1.2 mg/dL OR
• Creatinine clearance greater than 70 mL/min

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• No prior chemotherapy

Endocrine therapy:

• Not specified

Radiotherapy:

• No prior radiotherapy

Surgery:

• See Disease Characteristics