A preliminary comparative study of microwave ablation for cervical lymph node metastases originating from papillary thyroid carcinoma vs. non-papillary thyroid carcinoma.

Purpose: This study aims to evaluate the feasibility, efficacy, and safety of microwave ablation (MWA) for cervical lymph node metastasis (CLNM) originating from papillary thyroid carcinoma (PTC) versus non-papillary thyroid carcinoma (non-PTC).

Methods: In this retrospective study, 262 patients with CLNM treated by MWA between July 2016 and May 2024 were included. Comparative study based on propensity score matching (PSM) between the PTC and non-PTC groups was carried out.

Results: After PSM, 30 cases (median age, 54.5 years [IQR 48-65.3]; 26 women) in the PTC group and 10 cases (median age, 56.5 years [IQR 49.5-66]; 7 women) in the non-PTC group were followed for a median of 22.5 months [IQR 12-36] and 8 months [IQR 6-22.5] (p = 0.072), respectively. Statistical analysis revealed significant differences between the PTC and non-PTC groups in disease progression (13.3% vs. 50%, p = 0.029), distant metastasis (0% vs. 30%, p = 0.012), disease progression-free survival (68% vs. 45%, log-rank p = 0.003), and tumor disappearance progression-free survival (99.9% vs. 20%, log-rank p = 0.019). The only complication observed was transient hoarseness, with no significant difference in complication rates between the two groups (6.7% vs. 0%, p > 0.99). Significant reductions in MD and volume were observed between pre- and post-MWA at 1, 3, 6, 9, and 12 months (all p < 0.05).

Conclusion: MWA is a safe and effective treatment option for patients with CLNM from PTC. However, for CLNM from non-PTC, more aggressive monitoring and additional therapies after MWA may be necessary.