Late effects of I-131 therapy in the United States

The strengths of the study described in this paper were the high location and response rates, the relatively long follow-up time (long at least for studies of I-131, which did not receive widespread use until the early 1950s), and the careful validation of cancer diagnoses. The major weaknesses included the relatively small number of exposed patients and relatively low organ doses, which resulted in a low statistical power for detecting excess risks, especially for uncommon cancers such as leukemia. Questions such as the comparison of I-131 with x irradiation for cancer induction rates could not be addressed because of the small number of cases and the lack of good individual organ dosimetry. The authors hope to overcome these shortcomings by expanding the present effort in the United States and possibly in Europe