Compensated 131I-therapy of solitary autonomous thyroid nodules: effect on thyroid size and early hypothyroidism.

Thyroid function and thyroid gland volume, ultrasonically determined, were investigated in 27 hyperthyroid patients with solitary autonomous thyroid nodules before and during one year after 131I-treatment. Total thyroid volume decreased gradually from 40.9 +/- 3.5 ml (mean +/- SEM) before treatment to 23.9 +/- 1.8 ml (P less than 0.001) at 3 months after 131I-treatment. No further change was observed. All but two patients received only one dose of 131I, and in spite of a significant decrease also of the non-adenoma side of the gland, none became hypothyroid. We conclude that 131I-therapy has an important place in the treatment of solitary autonomous thyroid nodules since all our patients became euthyroid within 3 months, only 2 of 27 patients needed more than one dose of 131I, no cases of hypothyroidism occurred, and thyroid volume was substantially decreased.