- Maintenance: Treatment is given as a 12-week course for 6 courses (girls) or 11 courses (boys). Patients receive the assigned oral steroid twice a day on days 1-5, 29-33, and 57-61 of each course, vincristine IV on days 1, 29, and 57 of each course, and the assigned oral thiopurine daily during each course. Methotrexate IT is administered to girls on day 1 of each course and on day 84 of course 6, while boys receive 1 dose on day 1 of course 11. Patients also receive oral methotrexate on days 8, 15, 22, 29, 36, 43, 50, 57, 64, 71, and 78 of each course.