Radioactive iodine therapy for goitrous Hashimoto's thyroiditis

Hashimoto's thyroiditis is an autoimmune disease that can produce marked clinical symptoms when patients have large diffuse goiters.

This retrospective cohort study was designed to evaluate whether radioactive iodine (RAI) is effective for Hashimoto's thyroiditis with a large goiter. Starting in November 1999, 13 Hashimoto's patients with large goiters, whose thyroiditis was refractory to TSH suppression therapy with thyroid hormone administration [two men and 11 women with a mean age of 61.2 +/- 8.9 yr (50-79 yr)], were recruited for the present study. The duration of symptomatic goiter before undergoing RAI was 12.0 +/- 7.9 yr (4-33 yr). Thirteen millicuries of 131I was administered two to six times, at an interval of 1-6 months on an outpatient basis. Thyroid weight was measured ultrasonographically, or by computed tomography if ultrasound was not possible due to the large size of the goiter.

RAI was administered an average of 4.7 +/- 1.4 times (two to six times), with a total dose of 59.8 +/- 17.3 mCi (25.0-78.0 mCi). The observation period was 47.9 +/- 13.4 months (26-66 months) after the first RAI. The average weight of the thyroid gland was 125.3 +/- 57.7 g (42.9-269.4 g) before the first RAI, decreasing significantly to 49.7 +/- 25.8 g (18.3-93.3 g) after the last RAI (P < 0.001, paired Student's t test). The percent reduction from baseline was 58.7 +/- 14.2% (35.7-84.0%). None of the patients showed an increase in goiter size or complained of a pressure sensation after any of the RAI treatments.

RAI is effective in Hashimoto's thyroiditis with a large goiter.