Patients with CNS involvement receive a third course of treatment: C) etoposide IV over 1 hour on days 36-40, ifosfamide IV over 1 hour on days 36-40, oral dexamethasone twice daily on days 36-40, and G-CSF SQ or IV over 30 minutes beginning on day 41 and continuing until blood counts recover. Patients with CNS involvement receive a total of 7 courses of treatment (A-B-C-A-B-A-B).