Chemotherapy and Stem Cell Transplantation in Treating Children With Central Nervous System Cancer

OBJECTIVES: * Determine the feasibility of administering an outpatient protocol comprising high-dose carboplatin with autologous stem cell support and etoposide in pediatric patients with primary central nervous system malignancies. * Determine the maximum tolerated dose of carboplatin when administered in this regimen in these patients. * Determine the toxicity of this regimen in these patients. OUTLINE: This is dose-escalation study of carboplatin. Patients receive filgrastim (G-CSF) IV once daily for 6 days followed by a maximum of 5 apheresis sessions. If the target number of peripheral blood stem cells is not achieved, some patients receive G-CSF and undergo apheresis as above after a 2-week rest. At least 3 days after completion of G-CSF, patients receive high-dose carboplatin IV over 1 hour on day 1, stem cell reinfusion on day 3, G-CSF subcutaneously on days 4-18 and 43-61, and oral etoposide 3 times daily on days 21-42. Treatment continues for a maximum of 4 courses in the absence of disease progression or unacceptable toxicity. Cohorts of 3-6 patients receive escalating doses of carboplatin until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 2 of 3 or 2 of 6 patients experience dose-limiting toxicity. Patients are followed monthly for 1 year and then annually thereafter. PROJECTED ACCRUAL: A total of 3-15 patients will be accrued for this study.