Long-term efficacy of microwave ablation for multifocal papillary thyroid microcarcinoma: a 5-year follow-up study.

OBJECTIVES

Microwave ablation (MWA) has achieved excellent long-term efficacy in treating unifocal papillary thyroid microcarcinoma (UPTMC). The therapeutic effect of this treatment on multifocal papillary thyroid microcarcinoma (MPTMC) is unknown. Therefore, we evaluated the long-term efficacy of MWA for low-risk MPTMC and to provide evidence-based medicine for the revision of clinical guidelines.

METHODS

This study included 66 MPTMC patients with a total of 158 lesions, all of whom received MWA. We collected and retrospectively analyzed the patients' follow-up data before MWA, at 1, 3, 6, and 12 months posttreatment and every 6 months thereafter until 5 years posttreatment. We evaluated the MWA complication rate, technical success rate (TSR), lesion volume reduction rate (VRR), and complete disappearance rate (CDR) during follow-up and in those patients with tumor progression and delayed surgery.

RESULTS

After 60 months of follow-up, all 158 lesions disappeared in 66 patients, and the volume was reduced from 43.82 mm to 0.00 mm. The TSR and VRR were both 100%. The CDRs at 1 year, 2 years, and 3 years were 57.59%, 93.67%, and 100%, respectively. The complication rate was 3.03% (2/66), and the incidence of tumor progression was 3.03% (2/66), including one new intrathyroidal lesion and one cervical lymph node metastasis (LNM). These lesions were retreated with MWA, and the lesions disappeared during the follow-up period.

CONCLUSIONS

Ultrasound-guided MWA for low-risk MPTMC is safe and effective and may serve as an alternative option for patients who refuse surgery or active surveillance (AS).

CLINICAL RELEVANCE STATEMENT

This study concludes that ultrasound-guided microwave ablation for low-risk multifocal papillary thyroid microcarcinoma is safe and effective and may serve as an alternative option for patients who refuse surgery or active surveillance.

KEY POINTS

• Ultrasound-guided microwave ablation for low-risk multifocal papillary thyroid microcarcinoma is safe and effective. • During 5 years of follow-up, multifocal papillary thyroid microcarcinoma patients treated with microwave ablation had a favorable prognosis. • To provide evidence-based medicine for the revision of clinical guidelines.