LEUKEMIA AFTER RADIOIODINE THERAPY FOR HYPERTHYROIDISM.

In a group of 650 patients with hyperthyroidism treated with radioiodine between 1945 and 1961, two cases of leukemia occurred. In one patient the diagnosis of chronic lymphatic leukemia was made three years after the I(131) therapy. Acute or subacute myelomonocytic leukemia developed in the other patient after an interval of 14 years. However, no conclusions can be drawn regarding a possible causal relationship between such therapy and the subsequent occurrence of leukemia. With passage of time, an ever increasing number of cases of leukemia can be expected in such patients on the basis of natural occurrence alone.