Radiofrequency versus microwave ablation for non-functioning benign thyroid nodules: a single-institution comparative cohort study.

PURPOSE: Thermal ablation (TA) has emerged as an alternative to surgery in selected patients with benign thyroid nodules, achieving substantial nodule volume reduction with improved cosmesis and lower risk of post-procedural hypothyroidism than thyroidectomy. However, comparative data from North American practice remain limited. We compared the efficacy and safety of radiofrequency ablation (RFA) and microwave ablation (MWA) for non-functioning benign thyroid nodules.

METHODS

In this single-institution comparative cohort, 224 patients with 291 nodules underwent RFA and 47 patients with 60 nodules underwent MWA for non-functioning benign thyroid nodules (2019-2025). Nodule volume, volume reduction ratio (VRR), symptoms, cosmesis, and complications were compared between the modalities over a 12-month follow-up period.

RESULTS

Baseline volumes were larger in the MWA cohort (median 29.0 vs. 16.6 mL, p = 0.004). Median VRR reached 77.8% (RFA) and 70.8% (MWA) by 12 months, with no significant between-group difference at any timepoint. After adjustment for baseline volume, estimated mean volume did not differ significantly between modalities. Final nodule volume tracked closely with baseline volume across volume groups. Median symptom and cosmesis scores improved for each group post-ablation. Complication rates were low and similar between groups, the most common being periprocedural pain (15.6% RFA, 12.8% MWA).

CONCLUSION

RFA and MWA achieved comparable volume reduction, symptom improvement, and complication rates for non-functioning benign thyroid nodules.