[Thyroxine therapy in benign thyroid nodules]

Levothyroxine (LT4) treatment in benign thyroid nodules is a controversial management. The favorable response varies between 10-60%, being, in some studies, comparable between treated and untreated groups. The aim of this study was to evaluate the response of uninodular goiter at the LT4 treatment, in comparison with untreated patients. The study group (S) included 53 patients diagnosed with nodular goiter, treated with LT4 for 1 year. 26 patients with nodular goiter, age and sex-matched, untreated, constituted the control group (C). All patients were from a minor iodine deficient area. The including criteria were euthyroidism, single nodule, solid (ultrasonography), cold (Scintigraphy), and benign (FNAB). After 1 year mean nodular volume had a significant decrement in both groups, higher in group S (35%: from 7.8 to 5.2 mL, p = 0.0098) than in group C (25%: from 8.4 to 5.9 mL, p = 0.026). Linear regression showed a slight correlation between the nodular decrement and the initial volume (r = 0.23): the responders percentage was higher in nodules with a volume < 5 ml than in those with volume > 5 ml (51.5% vs o 19.6%, p < 0.0001). The evolution of treated nodules seamed to be better than of the untreated ones, but the differences were only slightly significant. We believe that the evolution of thyroid nodules under LT4 treatment can be influenced by the iodine supply, since in most of the studies from minor iodine deficiency regions (Europe, South America) the response is better than in regions with sufficient iodine supply (North America). Knowing the potential side effects of LT4 therapy, this kind of management of benign thyroid nodules should be reserved to selected cases.