OUTLINE: Nonrandomized study. Induction: 7-Drug Combination Chemotherapy with Leucovorin Rescue plus Triple Intrathecal Therapy (TIT). Cyclophosphamide, CTX, NSC-26271; Thiotepa, TSPA, NSC-6396; Vincristine, VCR, NSC-67574; Daunorubicin, DNR, NSC-82151; Dexamethasone, DM, NSC-34521; Etoposide, VP-16, NSC-141540; Methotrexate, MTX, NSC-740; with Leucovorin calcium, Citrovorum Factor, CF, NSC-3590; plus TIT: IT MTX; IT Cytarabine, IT ARA-C, NSC-63878; IT Hydrocortisone, IT HC, NSC-10483. Consolidation: 6-Drug Combination Chemotherapy with Leucovorin Rescue plus TIT. ARA-C; VP-16; Asparaginase (E. coli), ASP, NSC-109229; MTX; VCR; Methylprednisolone, MePRDL, NSC-19987; with CF; plus TIT. Reinduction: 7-Drug Combination Chemotherapy with Leucovorin Rescue plus TIT. CTX; TSPA; VCR; DNR; DM; VP-16; MTX; with CF; plus TIT.