- Chemotherapy: Patients receive vincristine IV on days 0, 14, and 28; carboplatin IV over 4 hours on day 0; methotrexate IV continuously over 24 hours on day 14; cyclophosphamide IV over 4 hours on day 28; and cisplatin IV continuously over 48 hours on days 42 and 43. Courses repeat every 56 days (8 weeks) for up to 12 months. Patients who achieve a complete response proceed to observation, as do those achieving a partial response with no tumor present on biopsy. Patients with biopsy proven residual tumors after 12 months of chemotherapy or recurrent tumors that don't have the potential to spread through the cerebrospinal fluid (CSF) proceed to local radiotherapy. Patients with unresponsive disease or progressive disease that has the potential to spread through the CSF proceed to craniospinal radiotherapy.