EFFICACY AND SAFETY OF RADIOFREQUENCY ABLATION VERSUS ETHANOL ABLATION

Objectives: Multinodular goiter is the most common thyroid disease in Mongolia. Recent guidelines suggest that a nodule without clinical symptoms should be treated with watchful waiting however, some patients require treatment because of cosmetic problems or symptoms. The main treatment remainssurgical resection, however, minimally invasive alternatives are being investigated. Ethanol ablation (EA), laser ablation, microwave ablation, and radiofrequency ablation (RFA) are safe and effective techniques for the treatment of nodular goiter. This retrospective review evaluates two widely used methods of ablation in Mongolia, ethanol ablation (EA) methods and RFA. Our objective is to compare volume reduction of single-session EA and RFA for thyroid nodules of different compositions and sizes. Materials and Methods: This retrospective study was approved by the Research Ethics Committee of the Mongolian National University of Medical Sciences and informed consent was obtained from all patients before EA and RFA. From January 2019 to January 2020, 50 patients with nodular goiter who underwent RFA (mean age 45.74 ±12.45 years) and 50 patients treated with sonography (US)-guided EA (mean age 36.52 ±9.61 years) were enrolled in this study. Nodules were assessed prior to treatment and at 1, 3, 6, and 12 months follow-up. Nodule volume, symptomatic and cosmetic assessmentscores were recorded at each time point. The primaryendpoint was the volume reduction ratio (percentage) at 1, 3, 6, and 12-month follow-ups. Secondary endpoints included therapeutic success rate, improvement of symptoms and cosmetic problems, and a number of major complications. Results: For the primary outcome of nodule volume reduction, in the RFA and EA groups, the absolute volume reductions at the 12-month follow-up were 62.8±13.2% (50) and 55.8±0.0% (n = 50) respectively. The treatment outcomes are summarized in Tables 3, 4, 5, and 6 and Figures 1, 2, 3, 4, 5, and 6. In RFA group, the mean volume reductions at the 1, 3, 6 and 12-month follow-ups were 33.0±11.0% (n = 50), 44.7± 17.0% (n = 50), 57.3± 14.7% (n = 50), and 62.8± 13.2% (n = 50), respectively. In EA group, the mean volume reductions at the 1, 3, 6 and 12-month follow-ups were 18.3±0.0% (n = 50), 30.5±0.0% (n = 50), 42.5±0.0% (n = 50), and 55.8±0.0% (n = 50), respectively. Conclusion: The purpose of this article is to review the current evidence relating to image-guided ablation of thyroid disease with a focus on clinical outcomes and complication rates for patients treated with this minimally invasive approach. EA may be appropriate as the first-line treatment modality for cystic thyroid nodules, which has comparable therapeutic efficacy to, but is less expensive than, RF ablation.