The role of irradiation in central nervous system treatment and prophylaxis for acute lymphoblastic leukemia.

The results of central nervous system (CNS) treatment with craniocervical irradiation and intrathecal methotrexate in 117 children with ALL achieved at the Joint Center for Radiation Therapy. The Children's Hospital Medical Center, and The Sidney Farber Cancer Center are presented. A classification related to meningeal disease which correlated with prognosis is presented and the patients are analyzed within these groups. Of 80 patients classified in the most favorable groups (I and II), no child has suffered primary CNS relapse. Of the remaining 37 patients in less favorable groups (III, IV, and V), eight patients have experienced CNS relapse, five following or in conjunction with bone marrow relapse. The technical features of irradiation are reviewed and related to success of the treatment.