Long-Term Efficacy of a Single Session of RFA for Benign Thyroid Nodules

A Longitudinal 5-Year Observational Study

Maurilio Deandrea; Pierpaolo Trimboli; Francesca Garino; Alberto Mormile; Gabriella Magliona; Maria Josefina Ramunni; Luca Giovanella; Piero Paolo Limone


J Clin Endocrinol Metab. 2019;104(9):3751-3756. 

In This Article

Abstract and Introduction


Context: Radiofrequency ablation (RFA) of benign thyroid nodules has been gaining consensus. However, no solid information on its long-term efficacy is available.

Objective: To analyze the long-term results of single-session RFA.

Design: Retrospective longitudinal observational study.

Setting: Primary care center.

Patients or Other Participants: Adult outpatients who underwent a single-session RFA and posttreatment follow-up of least 3 years.

Intervention: Ultrasound-guided RFA was performed after local anesthesia by "moving-shot" technique. RFA was performed with a median power of 55W and a median time of 14 minutes with an internally cooled 18-gauge electrode with an active 10-mm tip.

Main Outcome Measures: Objective (trend of nodule volume) and subjective (compressive and cosmetic concerns) response to RFA were evaluated. Continuous variables were analyzed by the Wilcoxon and ANOVA test and their correlations by using the Spearman test. Categorical variables were compared by Pearson χ 2 test.

Results: Two hundred and fifteen patients were included. An early significant reduction of nodule volume was found at 1 year, lasting up to 5 years. A 67% nodule shrinkage was observed at the end of the observation period. The best response was recorded in nodules below 10 mL (79% reduction early and 81% at 5 years). Patients' symptoms were significantly reduced.

Conclusions: This study, by demonstrating a durable shrinkage of benign thyroid nodules treated by RFA with an improvement of subjective symptoms, establishes the reliability of RFA as alternative to surgery in the management of thyroid nodules, thus representing a remarkable novelty for clinical practice.


Surgery has traditionally been the only treatment of benign thyroid lesions causing neck compressive symptoms. Indeed, this strategy rapid resolves local symptoms and discomfort. However, thyroid surgical interventions lead to a nonnegligible rate (7% to 19%) of mild to severe complications, depending on the extent of the operation (lobectomy vs total thyroidectomy).[1]

Therefore, several nonsurgical therapies for benign thyroid nodules have been proposed; these techniques have shown encouraging results and are being adopted worldwide.[2–22] Percutaneous ethanol injection is considered the treatment of choice for recurrent cystic nodules[3–5] but is not as effective for solid lesions. For the latter type of lesion, laser and radiofrequency have been used, with excellent results;[6–20] the efficacy and the safety of high-intensity focused ultrasounds and microwave therapy are unproven.[21,22] Therefore, laser thermal ablation and radiofrequency ablation (RFA) are the most widely used nonsurgical treatments of benign solid thyroid nodules, but few data are available on their long-term efficacy.

For laser thermal ablation, some studies have reported outcomes at 3 to 5 years, with a volume reduction of up to 50%.[19,20,23] RFA was introduced after laser ablation; most published articles have reported the results at 6 to 12 months, showing a volume reduction of about 50% to 85%.[6–17] Few studies have evaluated long-term results; those published have had a 2- to 4-year follow-up, although they differ in terms of number of treatment sessions, baseline ultrasound features, and final volume shrinkage. Therefore, although data in the literature show that RFA rapidly shrink nodules, the long-term persistence of the shrinkage must be confirmed in a larger series. Thus, we sought to evaluate the long-term effects of a single RFA session on both volume reduction and improvement in clinical symptoms in a large number of benign thyroid nodules, followed for >3 years after the procedure, in a region where goiter is endemic.