A PROSPECTIVE RANDOMIZED TRIAL OF LEVOTHYROXINE SUPPRESSIVE THERAPY FOR SOLITARY THYROID-NODULES

OBJECTIVE We examined the effects of L-thyroxine therapy versus placeb o over a 12-month period on volume of solitary thyroid nodules. DESIGN Prospective randomized clinical trial; placebo and control groups fol lowed for one year in three centres. PATIENTS One hundred and one euth yroid patients with single palpable colloid thyroid nodules. MEASUREME NTS Serum thyroid hormones, TSH, thyroglobulin, anti-thyroglobulin and anti-thyroid peroxidase antibodies measured at the first visit and af ter 2, 6 and 12 months; nodule volume and contralateral thyroid lobe t hickness measured by ultrasound in double blind fashion; nodule diamet er measured by palpation every 6 months. RESULTS In the treatment grou p the nodule volume measured by ultrasound decreased progressively but not significantly; in the placebo group no changes were demonstrated. The number of nodules which decreased in size was however significant ly larger in the treatment group. None of the initial parameters was p redictive for the response. In the treatment group the nodule size ass essed by palpation showed a significant decrease after 12 months when compared to baseline. CONCLUSIONS In non-endemic areas TSH suppression induces nodule volume reduction measured by ultrasound which, althoug h not significant, seems to be progressive and occurring only in a sub group of patients. Significant palpatory nodule reduction is probably related to decreased thickness of the surrounding thyroid tissue still responsive to TSH.