Microwave Ablation and Surgical Resection for Micropapillary Thyroid Carcinoma

The study aimed to compare the efficacy and safety of papillary thyroid microcarcinoma (PTMC) treated with microwave ablation(MWA) and surgery resection (SR), and to explore the tumor characteristics suitable for each treatment methods (such as with and without capsular invasion). The investigators organized 18 hospitals to participate in this multicenter study. Patients meeting following indications will be included in this study: 1. Biopsy pathology proved PTMC, but not high-risk subtype; 2. solitary mPTC, without US-detected gross extrathyroid extension; 3. no evidence of metastasis; 4 willing to participate in this study and perform regular follow-up. Patients themselves decide to receive MWA or SR for mPTC after medical consultation. Baseline characteristic including age, gender, thyroid function et al. will be collected. The treatment protocols of MWA and SR were according to the Chinese and international guidelines. The primary outcomes were the disease progression, including local tumor recurrence, lymph node metastasis, and distant metastasis. The secondary outcomes include thyroid function, complication rate, blood loss et al. Investigators will follow up enrolled patients and collect and upload data according to the trial. Treatment outcomes of tumor with and without US-detected capsular invasion was analyzes as subgroups.