Patients with stage IV disease with neuromeningeal involvement receive triple intrathecal therapy consisting of methotrexate, cytarabine, and methylprednisolone, then reinduction A for months 1, 2, and 3, then reinduction B for months 4, 5, and 6 (if T cell lymphoma). These patients also receive cerebral irradiation during months 4 and 5. Patients with pre-B cell disease receive cerebral irradiation after intensification therapy.