Purpose: This study aimed to evaluate the effectiveness of ultrasound (US)-guided radiofrequency ablation (RFA) treatment of benign thyroid nodules in consecutive large number series. To find out whether there is any difference according to the nature of the nodules, nodules were subdivided into two groups of predominantly solid vs. predominantly cystic lesions.
Methods: We retrospectively analyzed clinical data of thyroid nodules receiving percutaneous RFA treatment in our institution. We subdivided data into two groups according to the nodule's sonographic characteristics. We defined therapeutic success as a volume reduction rate >50% at 6 months post-RFA. The second ablation was performed in case where <50% VRR was achieved at 6 months. The primary endpoint was to identify factors prognosticating response to RFA treatment.
Results: A total of 1000 patients with 1619 thyroid nodules received US-guided RFA treatment. A volume reduction of >50% (therapeutic success) after the first ablation was 78.9% vs. 78.2% (p = 0.439) and 91.4% vs. 93.4% (p = 0.148) after the final ablation for predominantly cystic vs. predominantly solid lesions, respectively, with comparable post-interventional morbidity. RFA sessions were more frequent in the solid group than in the cystic group. Small volume of thyroid nodule (<4 mL) was the only factor significantly associated with therapeutic success in the multivariate analysis (OR 1.848; 95% CI 1.537-2.789, p = 0.030).
Conclusion: RFA was effective in reducing the volume of benign thyroid nodules volume with non-inferior result in PS group comparing to PC group and can be considered a principal treatment method for treating benign thyroid nodules, including cystic nodules.
Keywords: Benign thyroid nodule; Nature of thyroid nodule; Radiofrequency ablation; Therapeutic success; Volume reduction.