Skeletal Effects Following 224Ra Injections Into Humans

Abstract

Repeated injections of 224Ra into German patients have produced tooth breakage, growth retardation, benign exostoses, and malignant bone sarcomas. Tooth breakage was most frequent in adolescents 1120 yr old at 224Ra injection. Growth retardation and exostoses were most frequent in the very young children and were not induced in adults. Bone sarcomas have occurred in 54 of the 897 traced patients of known and unknown dose, with appearance times ranging from 3.5 to 22 yr after 1st 224Ra injection. For patients of known dose and injection span, bone sarcomas occurred in 35 of 204 juveniles (1110 rad average skeletal dose and 11 months average injection span), and in 13 of 612 adults (210 rad average skeletal dose and 6 months average injection span). For equal injection spans, the juveniles were only slightly more sensitive per rad than the adults to 224Ra-induced bone sarcomas. The incidence of bone sarcomas from a given dose of 224Ra increased as the span of the injection series increased, and this effect in humans has been confirmed in the Neuherberg mice.