Ultrasound-Guided Microwave Ablation Vs. Surgery for Low-Risk PapilaryThyroid Carcinoma

The inclusion criteria of this study were as followed: 1. PTC confirmed by fine-needle aspiration (FNA); 2. Confirmed low-risk mutation types by next-generation sequencing (NGS) before surgery; 3. No severe functional diseases, such as heart failure, severe respiratory diseases, or renal failure; 4. Availability of complete follow-up data. The exclusion criteria were as followed: 1. No local or distant metastasis assessed by imaging evaluations, including ultrasound or computed tomography (CT); 2. Lacking of preoperative genetic testing or inability to assess genetic test results; 3. Inability to complete follow-up or lost to follow-up during the study. Low-risk PTC is defined as: 1. Maximum tumor diameter ≤1 cm; 2. Solitary lesion; 3. No local or distant metastasis; 4. No tumor invasion into extrathyroidal tissues; 5. No vascular invasion; 6. Non-invasive pathological subtype for the primary lesion (invasive subtypes include tall cell, columnar cell, diffuse sclerosing, solid/trabecular, and oncocytic vari ants); 7. No history of head and neck radiotherapy during adolescence; 8. No family history of thyroid cancer; 9. Genetic testing showing BRAF V600E mutation (without concurrent TERT mutation), RAS family gene mutations, (HRAS, NRAS, KRAS), or other low-risk mutations, such as isolated RET/PTC) rearrangements. Intermediate-high risk PTC is defined as: 1. Maximum tumor diameter \>1 cm; 2. Multifocal thyroid cancer; 3. Local or distant metastasis; 4. Primary lesion with extrathyroidal extension; 5. Vascular invasion; 6. Primary lesion with an invasive pathological subtype; 7. History of head and neck radiotherapy during adolescence; 8. Family history of thyroid cancer; 9. Genetic testing revealing high-risk mutation combinations, such as BRAF V600E or RAS mutations with concurrent TERT or TP53 mutations, or RAS mutations combined with EIF1AX mutations.