Thyroid Research Thyroid Research Archive Nodular Goiter

Thyroxine therapy does not reduce the size of benign solitary thyroid nodules

(November 2002)

The background of the study. Patients with a benign solitary thyroid nodule are often treated with thyroxine (T4) to reduce the size of the nodule, but the efficacy of this treatment is uncertain.

How the study was done. The literature was searched to identify trials of T4 therapy in patients with a solitary thyroid nodule detected by palpation and proven to be benign by fine-needle aspiration biopsy. The patients were randomly assigned to take T4 or placebo for at least six months. Thyroid-nodule size was evaluated repeatedly by ultrasonography.

The results of the study. Six trials of T4 therapy in patients with a benign solitary thyroid nodule met the inclusion criteria and were therefore included in the analysis. The six trials included 346 patients (313 women, 33 men; age range, 34 to 48 years). At base line, the characteristics of the patients in the T4-treatment and control groups were similar. The duration of treatment ranged from 6 to 12 months, and the doses of T4 ranged from 1.5 to 3 µg/kg.

Overall, the volume of the thyroid nodule was reduced by more than 50 percent in 22 percent of the T4-treated patients and in 10 percent in the control patients; in only one trial was the difference statistically significant. The mean nodule volume was similar in both groups at the end of each trial in all but one trial.

The conclusions of the study. T4 therapy for 6 to 12 months does not result in a substantial decrease in nodule size in patients with a solitary thyroid nodule.

The original article. Castro MR, Caraballo PJ, Morris JC. Effectiveness of thyroid hormone suppressive therapy in benign solitary thyroid nodules: a meta-analysis. J Clin Endocrinol Metab 2002;87:4154-9.