Transient Hypothyroidism-Reply

In Reply.—  Following radioactive iodine therapy for toxic diffuse goiter (TDG), hypothyroidism may occur early or late, and may be transient or permanent. We recently reported an incidence of transient hypothyroidism of 11% in patients with TDG who were treated with 10 mCi of sodium iodide I 131.¹ This is similar to the incidence of transient hypothyroidism found by Volpé et al after they reviewed more than 500 cases at the Toronto General Hospital from 1950 to 1958.² Our data suggested that any patient with a persistent goiter who develops hypothyroidism within four months of therapy with¹³¹I should be suspected of having only transient hypothyroidism. I would agree with Dr Wortsman that there may be a larger population of patients that has transient hypothyroidism. We did not stop thyroid replacement in those hypothyroid patients whose goiter disappeared after treatment with¹³¹I. It certainly is conceivable