Early second radiofrequency ablation treatment gave rise to significantly greater nodule shrinkage at 12 months than single-session treatment for large-volume benign thyroid nodules

Abstract

<h3>Introduction</h3><p>Radiofrequency ablation (RFA) is an effective nonsurgical treatment for symptomatic benign thyroid nodules. Large-volume nodules (≥20-mL) often require 2 or more radiofrequency ablation sessions to achieve desirable shrinkage but the optimal interval between sessions remains unknown. We hypothesized that early (within 6 months) retreatment could improve nodule shrinkage. This study compared the 12-month volume reduction rate (VRR) and complications between single-session radiofrequency ablation and 2-session radiofrequency ablation within 6 months for large benign thyroid nodules.</p><h3>Methods</h3><p>Consecutive patients with cytologically proven benign thyroid nodules ≥20 mL undergoing radiofrequency ablation were prospectively assigned to undergo either single-session (group 1) or 2-session radiofrequency ablation within 6 months (group 2). All were followed up for at least 12 months after the initial radiofrequency ablation. Volume reduction rate was calculated as (baseline − current volume)/baseline volume × 100%. Complications were documented.</p><h3>Results</h3><p>Out of 67 nodules ≥20 mL that underwent radiofrequency ablation, 43 nodules (group 1: <em>n</em> = 23, group 2: <em>n</em> = 20) from 42 patients were analyzed. Both groups had comparable baseline nodule volumes (33.2 ± 14.9 mL vs 34.3 ± 12.5 mL) and clinical parameters (<em>P</em> > .05). The 6-month volume reduction rate was comparable (65.7 ± 13.2% vs 68.6 ± 13.3%, <em>P</em> = .264) but the 12-month volume reduction rate was significantly greater in group 2 (65.9 ± 17.1% vs 75.6 ± 11.5%, <em>P</em> = .019). Group 2 nodules continued to shrink from 6 to 12 months (<em>P</em> = .012), whereas group 1 nodules did not (<em>P</em> = .503). Two-session radiofrequency ablation within 6 months was the only significant factor associated with a 12-month volume reduction rate of ≥75% (odds ratio 4.375, 95% confidence interval 1.210–15.812, <em>P</em> = .024). No vocal cord paresis or hematoma requiring reoperation occurred.</p><h3>Conclusion</h3><p>Early retreatment with 2-session radiofrequency ablation within 6 months was safe and led to significantly greater nodule shrinkage at 12 months than single-session radiofrequency ablation.</p>