Radiofrequency ablation for thyroid Bethesda III nodules: preliminary results.

Purpose: The purpose of this study was to evaluate the feasibility of radiofrequency ablation (RFA) for thyroid nodules with cytological atypia of undetermined significance or follicular lesion of undetermined significance (AUS/FLUS, Bethesda III).

Materials and methods: A total of 28 adults presenting with 30 initial Bethesda III nodules underwent thyroid RFA at a single medical center. Thyroid nodules with Bethesda IV or V according to the second aspiration were excluded. All RFA procedures were performed using the free-hand, 'moving-shot' technique under local anesthesia. Clinical features and demographics, RFA details, nodule volume reduction rate (VRR), and complications were analyzed.

Results: The mean age of patients was 47.6 years, 82.1% of whom were females. Mean nodule volumes at pre-RFA, and at 6 months and 12 months post-RFA were 7.92, 2.42, and 1.25 mL, respectively, with a VRR of 77.9% at 6 months, and 87.4% at 12 months. Post-RFA complications were noted in two patients, one with transient vocal cord palsy and another with isthmus minor rupture.

Conclusion: RFA may be another safe alternative except for active surveillance or surgical excision for AUS/FLUS nodules with low-suspicion Thyroid Imaging Reporting and Data System features for patients who are unsuitable or strongly refuse surgery. Long-term results remain uncertain, thus further follow-up study is necessary.