Radiofrequency ablation (RFA) of autonomously functioning thyroid nodules (ATN) can be an alternative treatment option to surgical resection and iodine treatment, avoiding the risk of hypothyroidism. Hot nodules are hypervascular lesions and need more energy to be completely devascularized compared to non-functional nodules, which may render the technique less effective. The outcome of RFA for ATN was evaluated.

A single specialized endocrine surgeon treated 75 ATN out of 446 RFA in a 6 year period (2018-2024) using STAR RF fixed 18G-electrode with 7 or 10mm active tip and VIVA RF Generator, with benign results on FNA cytology. Success was defined as normalized TSH within 1 year postoperatively without medical treatment. Secondary outcome was volume reduction measured by an independent radiologist at 3-6 months and subsequently yearly intervals.

ATN size varied from 12 to 52 mm maximum diameter (0.5-19 ml) in 67 women and 8 men (µ age 49 range 18-82). Mean follow-up was 12 months. 65 patients became euthyroid with failure in 10 (13%) patients after one year of which three patients were retreated by RFA. Mean volume reduction ratio (VRR) was 59 and 77% at 6 months and one year follow-up. Complications encountered were temporary dysphonia (n=2), one peroperative pain and one superficial hematoma. One patient without anti-thyroid-antibodies developed Graves' disease during follow-up.

The outcome of RFA in ATN is successful in the large majority without severe complications and avoids hypothyroidism. Nevertheless incomplete devascularization of the nodule is frequent and requires long-term follow-up. A second RFA may be considered.