Evaluation of suppressive therapy for cold thyroid nodules with levothyroxine (a double blind placebo controlled clinical trial)

Thyroid nodules are present in up to 50 percent of adults in the fifth decade of their life. Patients are often treated with thyroxine in order to reduce the size of the nodule, but the efficacy of suppressive therapy with thyroxine remains uncertain. In this study, 62 patients with a benign cold thyroid nodule confirmed by biopsy and TC-99m pertechnetate scan, were randomly assigned in a double bline manner to receive placebo (n=30) or levothyroxine (n=32) for two years. High-resolution sonography was used to measure the size of the nodules before and 6,12 and 24 months after treatment. Suppression of thyrotropin release was confirmed in both groups by one session administration of thyrotropin-releasing hormone 1.5 months after treatment and TSH measurements 1.5 months after treatment and then every 3 months. After 24 months of therapy, diameter or volume of the cold nodules in the levothyroxine group did not significantly decrease as compared with the placebo group. We conclude that suppressive therapy with levothyroxine was not effective in reducing the size of thyroid nodule within 24 months, despite effective suppression of thyrotropin release.