- Patients with high-risk tumors after surgery are randomized to IVA as in strategy 952 (Arm I) or to 3 weeks of IVA (1 course) as in Strategy 952 followed by CEV and IVE as in Strategy 952 (Arm II). Response is assessed at week 8. Patients with parameningeal disease who are at least 3 years of age proceed to radiotherapy at week 9, regardless of response.