Central Nervous System Disease in Childhood Acute Lymphoblastic Leukemia: Prognostic Factors and Results of Treatment

(years) revealed that isolated CNS relapse had occurred in 70 children (9.0%). Of these 70 patients, 12 out of 142 children (8.5%) had initially received irradiation and 58 out of 628 children (9.2%) only chemotherapy as CNS-prophylaxis. There was a significant higher risk for boys (12%) than for girls (6%) to relapse in the CNS compartment. Unfavorable prognostic factors for survival after isolated CNS relapse were short duration of first remission and male sex. In high-risk patients after an isolated CNS relapse, there was no difference in prognosis related to treatment with or without irradiation as initial CNS prophylaxis.