- Induction therapy: All patients then receive induction therapy (PCV) comprising of oral lomustine on day 1, vincristine IV on days 8 and 29, and oral procarbazine on days 8-21. Treatment repeats every 42 days in the absence of progressive disease or unacceptable toxicity. Patients with prior complete resections receive 3 courses of PCV then proceed to high-dose chemotherapy and transplantation as described below, provided tumor has not recurred. Patients with prior partial resections or biopsies receive 2 courses of PCV and are assessed for response; those who achieve complete response (CR) or major partial response (PR) receive 1 more course of PCV. Patients who achieve partial response or have stable disease receive 2 more courses of PCV and are reassessed.