Dexamethasone 20 mg/m2/day PO or IV Days 1-6.Cytarabine 2 grams/m2, 3-hour IV infusion every 12 hours Days 1-2. Etoposide 100 mg/m2, 1-hour IV infusion every 12 hours Days 3-5. Intrathecal methotrexate+hydrocortisone+cytarabine (ITMHA) Day 5; PEG-asparaginase 3,000 units/m2 IV Day 6