Preliminary report of microwave ablation for the primary papillary thyroid microcarcinoma: a large-cohort of 185 patients feasibility study

Purpose To assess the safety and efficacy of microwave ablation (MWA) for primary papillary thyroid microcarcinoma (PTMC) with a large sample of 185 patients. Methods A total of 185 patients underwent MWA for 206 primary PTMC nodules. They received ultrasound follow-up at 1, 3, 6, and 12 months after MWA and every 6 months thereafter. Nodule volumes were calculated at each follow-up and compared with those before MWA. Additionally, the volume reduction rate (VRR) of the nodules was calculated. Patients' thyroid functions were tested before and 1 month after MWA. Results The mean follow-up time of the 185 patients was 20.7 +/- 8.8 months (range 12-36 months). During the follow-up period, the mean volume of the 206 nodules was 100.1 +/- 92.9 mm(3) (range 3.6-423.9) before MWA, which decreased to 2.2 +/- 5.6 mm(3) (range 0-20.3 mm(3)) after MWA (P = 0.000). The mean VRR of the nodules was 98.65 +/- 3.60% after MWA (range 83.85-100%). One hundred and seventy four of 206 nodules (84.5%) were fully absorbed. Compared with the preoperative results, no significant variation in thyroid function was observed 1 month after MWA. Thirty-eight patients (20.5%) had different types of complications, ranging from minor to major. Five patients (2.7%) had hoarseness, 11 patients (5.9%) had bleeding, 21 patients (11.4%) had earache or toothache, and one patient had another lesion 1 month after MWA. Conclusions This preliminary study suggests that MWA is safe and effective in the treatment of primary PTMC and offers a new alternative for clinical treatment.