Radiation therapy has been widely applied for cancer treatment. Childhood acute 
lymphocytic leukemia (ALL), characterized by frequent central nervous system 
involvement, is a well documented disease for the effect of prophylactic 
cranio-spinal irradiation. Irradiation, however, acts as an oncogenic factor as 
a delayed effect and it is rare that glioblastoma multiforme develops during the 
remission period of ALL. We experienced a pediatric radiation-induced GBM 
patient which developed during the remission period of ALL, who were primarily 
treated with chemotherapeutic agents and brain radiation therapy for the 
prevention of central nervous system (CNS) relapse. Additionally, we reviewed 
the related literature regarding on the effects of brain irradiation in 
childhood and on the prognosis of radiation induced GBM.