Conspicuousness and recurrence related factors of ultrasound-guided microwave ablation in the treatment of benign thyroid nodules

OBJECTIVE: Microwave ablation (MWA) is a minimally invasive technique for the treatment of benign thyroid nodules. The purpose of this study was to evaluate efficacy and safety of ultrasound-guided MWA in the treatment of benign thyroid nodules, and to find out the recurrence related factors, so as to provide reference for future clinical work. METHODS: This study retrospectively analyzed the patients who received ultrasound-guided MWA for benign thyroid nodules in our hospital from October 2018 to March 2020. A total of 214 patients were included in the study. We assessed thyroid volume changes (represented by volume reduction ratio VRR), the energy per 1 mL reduction in nodular volume (represented by energy volume ratio ΔE), the serum levels of free triiodide thyroid hormone (FT3), free thyroxine (FT4), thyrotropin (TSH) and complications after MWA treatment. RESULTS: There were a total of 306 nodules in 214 patients, including 183 (85.51%) females and 31 (14.49%) males. The median diameter and volume of the nodule were 33 mm and 8.01 mL. The VRR at 1 month, 3 months, 6 months and 12 months were 40.79%, 60.37%, 74.59% and 85.60%, respectively. In addition, MWA had a better ablation effect for small nodules (initial volume ≤ 10 mL). In recurrent studies, we found that ΔE was an independent risk factor for benign thyroid nodules (P < 0.05). CONCLUSIONS: Ultrasound-guided MWA is effective and safe in the treatment of benign thyroid nodules. In addition, it has little damage to surrounding tissues and no effect on thyroid function. Especially, the nodules with smaller initial volume, the treatment is better. On the other hand, the energy per 1 mL reduction ΔE in nodular volume may be associated with nodular recurrence, which requires further follow-up for longer periods. At this stage, we consider that ultrasound-guided MWA can be used as one of the main clinical treatment methods for benign thyroid nodules.