Efficacy of 7 versus 10 mm Active Tips in Thyroid Radiofrequency Ablation for Benign Nodules

Radiofrequency ablation (RFA) is an effective treatment modality for benign thyroid nodules, but several factors can influence the extent of volume reduction. This study compares the effectiveness of 7- versus 10-mm active tips in terms of volume reduction rate (VRR), defined as the percentage decrease in nodule volume after RFA over 12 months.

This retrospective longitudinal cohort study was conducted at an academic U.S. institution from December 2021 to November 2024, and included patients who underwent RFA performed by a single endocrinologist. Patients with benign thyroid nodules were included; those with thyroid cancer or parathyroid adenoma were excluded.

We identified 35 patients; females were 91.4%, with a mean age of 50.6 ± 17.5 years. The active tips used were 7 mm (n = 22) and 10 mm (n = 13). The initial nodule volumes were stratified in 3 groups: <10 mL (45.5% and 46.2%), 10 to 20 mL (27.3% and 23.1%), and ≥20 mL (27.3% and 30.8%), respectively. Volume measurements were conducted at baseline and at 1, 3, 6, and 12 months post-RFA.Comparing VRR with 7- versus 10-mm active tips across the whole cohort showed significant differences at 1 month (47.1 ± 24.7% vs 27.3 ± 28.8%, P = 0.044), 3 months (74.1 ± 20.1% vs 52.0 ± 20.0%, P = 0.035), 6 months (74.6 ± 19.0% vs 54.6 ± 13.6%, P = 0.016), and 12 months (85.9 ± 22.4% vs 59.3 ± 20.0%, P = 0.031), respectively. Ablation duration was 51.9 [24.2-71.2] and 40.0 [18.2-72.3] seconds, respectively, P = 0.436. Delivered energy was 1.1 [0.5-1.5] and 1.7 [0.8-4.0] KJ, respectively, P = 0.350.

In thyroid RFA, the 7-mm active tip can achieve better VRRs than the 10-mm tip.