Radiofrequency vs. Microwave Ablation for Benign Thyroid Nodules: A Randomized Prospective Comparative Study

Introduction: Percutaneous thermal ablation represents a minimally invasive alternative to surgery for benign thyroid nodules. Although both techniques are effective in volume reduction, a direct comparison of their performance and safety is fundamental . The aim of this study was to compare the efficacy of microwave ablation versus radiofrequency ablation in terms of volume reduction and safety in patients with benign thyroid nodules at 60 days and 6 month post-procedure follow-up.

Methods: Prospective Randomized study, conducted from October 2024 to April 2026, with patients with benign thyroid nodules measuring more than 3cm. We analyzed size of the nodule, nodule characteristics, procedure time, type of energy deployed, amount of energy deployed, Volume reduction rate after 30 days, 45 days, 90 days, 180 days.

Results: Ablation was performed on nodules with volumes ranging from 2.44 to 35.28 cm³ (mean 11.80, standard deviation 7.23). Ablation time varied according to the energy modality. RF: 2 min 15 sec to 34 min 36 sec (mean 12 min 50 sec - standard deviation 8 min 24 sec). MW: 1 min 22 sec to 15 min 42 sec (mean 5 min 25 sec - standard deviation 4 min 22 sec). When comparing the two energy modalities and the ablation time, a Student 's t-test of 3.041 with a p- value of 0.005 was observed.All procedures were performed on an outpatient basis, in a surgical center, using sedation and local anesthesia, with an average hospital stay of 8 hours and 54 minutes (Standard Deviation: 2 hours and 42 minutes).
The amount of energy used varied depending on the modality employed. On average, 29632.53 Joules in the RF case and 12650.60 Watts in the MW case. There were no serious intraoperative complications . Recovery was rapid, with 92.9% of patients returning to their usual activities within 72 hours.

Conclusions: Radiofrequency and microwave ablation are safe and effective options for benign thyroid nodules. Microwave ablation showed operational advantages, with shorter ablation time and lower energy requirements, suggesting greater efficiency. Early volume reduction was similar between the techniques.