LEVOTHYROXINE SUPPRESSIVE THERAPY IS PARTIALLY EFFECTIVE IN TREATING PATIENTS WITH BENIGN, SOLID THYROID-NODULES AND MULTINODULAR GOITERS

We prospectively evaluated the effect of thyrotropin (TSH)-suppressive therapy with levothyroxine (LT4) on the size of a benign, solitary, s olid nodule and multinodular goiter in a relatively low iodine intake area. In this study, 101 euthyroid subjects with a benign, solitary, p redominantly solid nodule (n = 54) confirmed by biopsy or multinodular goiter (n = 47) received 200 mu g of levothyroxine daily as a single morning tablet for 12 months. Thirty-five receiving no therapy were co nsidered as controls (solitary nodules, n = 20, multinodular, n = 15). Patients were admitted to the study after evaluation of thyroid bioch emical parameters (thyroxine [T-4], free thyroxine [FT4], triiodothyro nine [T-3], thyrotropin [TSH], and thyroglobulin [Tg]), thyroid scanni ng, ultrasound examination, and fine-needle aspiration biopsy. Every 3 months, thyroid function tests and every 6 months ultrasound examinat ions were repeated. Twelve months later 20 of 54 (37.1%) patients with single, solid nodules had 50% or more regression of the nodular volum e (responders). Eleven of 54 (20.3%) patients had more than 20%, but l ess than 49.9% reduction of nodular volume (partial responders). Nonre sponders were 23 of 54 (42.5%). One-third of subjects with multinodula r goiter had 50% or more regression of the glandular volume, whereas 4 6.8% were considered as nonresponsive. The mean serum Tg levels decrea sed significantly only in responders with solitary nodular disease or multinodular goiter. In the control group only 1 patient (5% of total) with a solitary nodule had a 50% reduction in the nodular volume. Fiv e others had a partial response (<49%, >20% reduction). None of the pa tients with multinodular goiter had a significant reduction (>50%) of the combined nodular volumes. We concluded that LT4 may be effective, among other factors, in arresting the growth or in reducing the volume of relatively small, benign, solitary, solid thyroid nodules or the c ombined nodular volume of multinodular goiter.