I-131 AND PEDIATRIC THYROID-CANCER POST-CHERNOBYL - CAUSE AND EFFECT

The association between radiation exposure and subsequent thyroid canc er has been demon strated conclusively in epidemiological studies of c hildren receiving external head and neck x-ray irradiation and in surv ivors of the atomic bomb exposures in Japan. Previous studies, however , have failed to demonstrate any causal association between diagnostic or therapeutic I-131 administration and thyroid cancer risk, although data regarding the pediatric population are scarce. New evidence emer ging since the Chernobyl accident suggests that exposure to I-131 can cause thyroid cancer in children and adolescents, but further epidemio logical studies are required to prove this hypothesis conclusively, Un til the question is settled definitively, clinicians are urged to exer cise due caution when considering the use of I-131 for diagnostic appl ications or when treating hyperthyroid states in individuals younger t han age 20.