Initial ablation ratio predicts the recurrence of low-risk papillary thyroid microcarcinomas treated with microwave ablation: a 5-year, single-institution cohort study

Abstract

Objective: To assess the long-term efficacy and safety of microwave ablation (MWA) in treating low-risk papillary thyroid microcarcinomas (PTMC) and to identify predictive factors for the postoperative local tumor progression of PTMC. Methods: A total of 154 low-risk PTMC patients treated with MWA who were followed up for at least 3 months were retrospectively recruited. Ultrasonography was performed after MWA to assess the local tumor progression. Adverse events associated with MWA were recorded. The ablated volume (Va) and initial ablation ratio (IAR) were measured to assess their influences on the recurrence risk of PTMC. Results: The mean tumor volume of PTMC before MWA was 0.071 (0.039, 0.121) cm3, with a maximum diameter of 0.60 ± 0.18 cm. All PTMC patients were followed up for 6 (3, 18) months. Va increased immediately after MWA, then gradually decreased over time, till significantly smaller at 12 months than that before MWA (P 2.0 mU/L) of PTMC patients were not correlated with local tumor progression. Conclusion: MWA is an effective therapeutic strategy for low-risk PTMC with high safety. The maximum tumor diameter and IAR are predictive factors for the local tumor progression of PTMC after MWA.

Keywords

• microwave ablation
• recurrence
• papillary thyroid microcarcinoma
• initial ablation ratio