Efficacy and safety of thermal ablation for Bethesda III/IV thyroid nodules: a retrospective study.

Objectives: To evaluate the efficacy and safety of thermal ablation (TA) for the treatment of Bethesda III and IV thyroid nodules.

Materials and methods: A retrospective analysis was conducted on 154 patients with Bethesda III (n = 82) and IV (n = 72) thyroid nodules treated with microwave or radiofrequency ablation between December 2016 and October 2023. Patients were followed for a median of 19 months. Outcomes assessed included nodule volume reduction rate (VRR), complications, and disease progression.

Results: The median VRR at 12 months was 97% (Bethesda III) and 88% (Bethesda IV), increasing to 100% and 96% by 36 months, respectively, with no significant differences between groups. No major complications were encountered, minor complications occurred in 4 patients (4/154, 2.6%), including 3 cases of transient hoarseness and 1 case of neck pain, resolving spontaneously. Disease progression (3/154, 1.9%) occurred in both groups, with new tumor in each group, no other disease progression occurred.

Conclusion: Thermal ablation could be a safe, effective, and minimally invasive alternative to surgery for Bethesda III/IV thyroid nodules, achieving substantial volume reduction with minimal complications.