Safety and Efficacy of Radiofrequency Ablation of Thyroid Nodules-Expanding Treatment Options in the United States

Abstract

Context: Radiofrequency ablation (RFA) has only recently gained popularity in the United States for treatment of thyroid nodules (TNs), with a limited number of patients having undergone the procedure in this country.

Objective: To evaluate the safety and efficacy of RFA of TNs performed in an outpatient setting in the United States.

Methods: This is a retrospective, single-center study of 53 patients who underwent RFA of 58 TNs between November 2018 and January 2021. The reduction in volume of nodule, cosmetic and symptomatic improvement, effect on thyroid function, and complications following RFA were assessed.

Results: Eleven out of 53 patients were excluded from the analysis. A total of 47 benign TNs (23 nonfunctioning thyroid nodules [NFTNs] and 24 autonomously functioning thyroid nodules [AFTNs]), were assessed after RFA. The median reduction in volume was 70.8% after a median follow-up period of 109 days, with symptomatic and cosmetic improvement (P < 0.0001). Compared with larger nodules, smaller nodules had greater volume reduction (P = 0.0266). RFA improved thyrotropin (TSH) in AFTNs (P value = 0.0015) and did not affect TSH in NFTNs (P value = 0.23). There were no major complications; however, 1 patient had self-limited local bleeding and another had transient voice change that recovered in 6 months.

Conclusion: RFA is a safe and efficacious treatment for symptomatic NFTNs and AFTNs in our population and is especially effective for smaller nodules. RFA should be considered an alternative for TNs in patients who cannot or do not want to undergo surgery.

Keywords: autonomously functioning thyroid nodule; radiofrequency ablation; thyroid nodules.

Figure 1.

Ultrasonographic image (transverse view) of radiofrequency ablation electrode in thyroid nodule. White arrow pointing towards electrode inserted in the middle part of the thyroid nodule (TN) using the ‘trans-isthmic’ approach (from medial to lateral) with tip surrounded by hyperechoic area indicating ablated zone. In this approach, the electrode tip points away from the trachea (T) limiting heat exposure to the recurrent laryngeal nerve located between the trachea (T) and the inferior pole of the thyroid lobe. Inserting the electrode from medial to lateral, rather than lateral to medial also avoids the neurovascular bundle. Abbreviations: ACSM, anterior cervical strap muscles; CCA, common carotid artery.

Figure 2.

Change in volume over time in nonfunctioning thyroid nodules (NFTN) after radiofrequency ablation (RFA). Each line represents an individual nodule; Time 0 days indicates the day of the RFA procedure, with the length of the line representing length of follow-up period. Each circle represents a point in time where volume of the nodule was measured by ultrasonography, and the points are connected by lines to give an approximate rate of volume reduction. A, Change in volume of NFTNs with initial volumes of less than 20 mL. B, Change in volume of NFTNs with initial volumes of more than 20 mL.

Figure 3.

Change in volume over time in autonomously functioning thyroid nodules (AFTN) after radiofrequency ablation (RFA). Each line represents an individual nodule; Time 0 days indicates the day of the RFA procedure, with the length of the line representing length of follow-up. Each circle represents a point in time where volume of the nodule was measured by ultrasonography, and the points are connected by lines to give an approximate rate of volume reduction. A, Change in volume of AFTNs with initial volumes of less than 20 mL. B, Change in volume of AFTNs with initial volumes of more than 20 mL.

Figure 4.

Change in volume over time of incidental thyroid nodules that did not undergo radiofrequency ablation (RFA). Each line represents an individual nodule; Time 0 days indicates the day RFA was performed on the contralateral nodule, with the length of the line representing length of follow-up. Each circle represents a point in time where volume of the nodule was measured by ultrasonography, and the points are connected by lines to give an approximate rate of volume reduction. A, Change in volume of incidental thyroid nodules in patients who underwent RFA of nodules with initial volume <20 mL. B, Change in volume of incidental thyroid nodules in patients who underwent RFA of nodules with initial volume >20 mL.