Treatment of Graves' Hyperthyroidism with Radioiodine: Results of a Prospective Randomized Study

In this paper, we report the results of a randomized prospective study on radioiodine treatment in patients with Graves' hyperthyroidism. Complete data were obtained in group 1 from 98 patients 6 months after application of a standard activity of 15 mCi (555 MBq) of 131 I and in group 2 from 107 patients who received a target dose of 100 Gy. In group 1, the overall success rate was 71%, but the results in the subgroups clearly were related inversely to the thyroid volume, ranging from 100% in patients with a thyroid volume 60 mL. In contrast, patients who received a target dose of 100 Gy showed very similar results, with success rates of about 40-50% in all but one subgroup. Only patients with a thyroid volume