COMPARISON OF THREE METHODS OF CENTRAL-NERVOUS-SYSTEM PROPHYLAXIS IN CHILDHOOD ACUTE LYMPHOBLASTIC LEUKÆMIA

A retrospective comparison was made of three methods of central-nervous-system prophylaxis in childhood acute lymphoblastic leukæmia; (1) intrathecal methotrexate only; (2) intermediate-dose methotrexate infusion and intrathecal methotrexate and; (3) 2400 rads cranial irradiation and intrathecal methotrexate. The incidence of primary meningeal relapse was statistically significantly lower in both standard-risk patients (age >24 months and ≤120 months white-cell count 120 months and/or white-cell count >20 000) whose central-nervous-system prophylaxis included cranial irradiation. The disease-free and overall survival of irradiated increased-risk patients was significantly better than that of unirradiated increased-risk patients. The disease-free survival of standard-risk patients who received intermediate-dose methotrexate was statistically superior to that of the remaining standard-risk patients. There were no significant differences in overall survival between the three groups of standard-risk patients.