Treatment schema and events according to the treatment arm. COP: cyclophosphamide (300 mg/m2, day 1), Oncovin (vincristine; 1 mg/m,2 day 1), prednisone (60 mg/m2/d, days 1-7), plus intrathecal methotrexate (IT MTX, day 1); COPADM: cyclophosphamide (1.5 g/m2 in COPADM1, 3 g/m2 in COPADM2), Oncovin (2 mg/m2, day 1), prednisone (60 mg/m2/d, days 1-7), Adriamycin (doxorubicin; 60 mg/m2, day 2), high-dose (HD) MTX (3 g/m2 in 3-h infusion, day 1, plus leucovorin rescue starting at hour 24 until serum MTX level is less than 1 × 10−7 M) plus IT MTX, day 2 and day 6. CYM: cytarabine (100 mg/m2 in continuous infusion, days 2-6, plus IT cytarabine, day 6), HD MTX (3 g/m2 in 3-h infusion, day 1, plus leucovorin rescue, plus IT MTX, day 2). M1: cyclophosphamide (1 g/m2), Oncovin (2 mg/m2, day 1), prednisone (60 mg/m2/d, days 1-7), Adriamycin (60 mg/m2, day 2), HD MTX (3 g/m2 in 3-h infusion, day 1, plus leucovorin rescue starting at hour 24) plus IT MTX, day2. IT: intrathecal injections: all are with hydrocortisone and age-adjusted. Oncovin: max 2 mg.
