A clinical study of microwave ablation for cervical lymph node metastasis from papillary thyroid cancer

The aim of this study is to evaluate the efficacy and safety of microwave ablation (MWA) for cervical lymph node metastasis (LNM) in initially treated, post-ablation and post-resection papillary thyroid cancer (PTC) patients.

A total of 131 patients with 535 LNM from PTC who underwent ultrasound-guided MWA were included in the retrospective study. Patients were divided into three subgroups on the basis of treatment timing: initially treated, after PTC ablation (post-ablation), or after resection (post-resection). Changes in cervical metastatic lymph nodes as well as the incidences of complications, tumour recurrence and progression were compared.

The technical success rate of this study was 100% (535/535). Compared with those before MWA, the mean largest diameter and volume of the metastatic lymph nodes were significantly lower (p <0.01) at each follow-up. Transient hoarseness was the exclusive major complication with a total rate of 5.3% (9/171), which significantly differed in terms of incidence among the three subgroups (p<0.01). Lymph node location in region VI was an independent risk factor for transient hoarseness. The total recurrence rate was 22.8% (39/171) without statistically significant difference among the three sub-groups (p=0.20). Two cases received repeated surgery, while re-ablation was conducted successfully in all rest of cases. Data from the latest follow-up revealed one death due to LNM.

MWA is a safe and effective treatment option for LNM in initially treated, post-resection and post-ablation PTC patients.