Comparison of the Therapeutic Efficacy and Technical Outcomes between Conventional Fixed Electrodes and Adjustable Electrodes in the Radiofrequency Ablation of Benign Thyroid Nodules

Jae Ho Shin; Minkook Seo; Min Kyoung Lee; So Lyung Jung

doi:10.3348/kjr.2023.0577

Comparison of the Therapeutic Efficacy and Technical Outcomes between Conventional Fixed Electrodes and Adjustable Electrodes in the Radiofrequency Ablation of Benign Thyroid Nodules

Korean J Radiol. 2024 Feb;25(2):199-209. doi: 10.3348/kjr.2023.0577.

Authors

Jae Ho Shin^{1

2}, Minkook Seo³, Min Kyoung Lee⁴, So Lyung Jung⁵

Affiliations

¹ Department of Radiology, Anam Hospital, Korea University College of Medicine, Seoul, Republic of Korea.
² Department of Radiology, St. Vincent's Hospital, The Catholic University of Korea, Suwon, Republic of Korea.
³ Department of Radiology, Seoul St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea.
⁴ Department of Radiology, Yeouido St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea.
⁵ Department of Radiology, Yeouido St. Mary's Hospital, The Catholic University of Korea, Seoul, Republic of Korea. sljung1@catholic.ac.kr.

Abstract

Objective: This study aimed to compare therapeutic efficacy and technical outcomes between adjustable electrode (AE) and conventional fixed electrode (FE) for radiofrequency ablation (RFA) of benign thyroid nodules.

Materials and methods: Between 2013 and 2021, RFA was performed on histologically proven benign thyroid nodules. For the AE method, AE length ≥ 1 cm with higher power and < 1 cm with lower power were utilized for ablating feeding vessels and nodules, especially those near anatomical structures, respectively. The therapeutic efficacy (volume reduction rate [VRR], complication rate, and regrowth rate) and technical outcomes (total energy delivery, ablated volume/energy, RFA time, and ablated volume/time) of FE and AE were compared. Continuous parameters were compared using a two-sample t-test or Mann-Whitney U test, and categorical parameters were compared using a chi-squared test or Fisher's exact test.

Results: A total of 182 nodules (FE: 92 vs. AE: 90) in 173 patients (mean age ± standard deviation, 47.0 ± 14.7 years; female, 90.8% [157/173]; median follow-up, 726 days [interquartile range, 441-1075 days]) were analyzed. The therapeutic efficacy was comparable, whereas technical outcomes were more favorable for AE. Both electrodes demonstrated comparable overall median VRR (FE: 92.4% vs. AE: 84.9%, P = 0.240) without immediate major complications. Overall regrowth rates were comparable between the two groups (FE: 2.2% [2/90] vs. AE: 1.1% [1/90], P > 0.99). AE demonstrated a shorter median RFA time (FE: 811 vs. AE: 627 seconds, P = 0.009). Both delivered comparable median energy (FE: 42.8 vs. AE: 29.2 kJ, P = 0.069), but AE demonstrated higher median ablated volume/energy and median ablated volume/time (FE: 0.2 vs. AE: 0.3 cc/kJ, P < 0.001; and FE: 0.7 vs. AE: 1.0 cc/min, P < 0.001, respectively).

Conclusion: Therapeutic efficacy between FE and AE was comparable. AE demonstrated better technical outcomes than FE in terms of RFA time, ablated volume/energy, and ablated volume/time.

Keywords: Nodule; Radiofrequency ablation; Thyroid; Ultrasound.

MeSH terms

Catheter Ablation* / methods
Electrodes
Female
Humans
Radiofrequency Ablation* / methods
Retrospective Studies
Thyroid Nodule* / diagnostic imaging
Thyroid Nodule* / pathology
Thyroid Nodule* / surgery
Treatment Outcome