Clinical Research Directory

Inclusion Criteria: 1. Pathological confirmation of PTC. 2. Patients who underwent primary surgery accompanied by central neck lymph node dissection. 3. Tumors measuring less than 2 cm in diameter. 4. Postoperative pathological reports including detailed information on the number of lymph nodes dissected and the number of metastatic lymph nodes. 5. Availability of comprehensive preoperative thyroid ultrasound images for analysis. Exclusion Criteria: 1. Postoperative pathological diagnosis indicating sub-types of PTC. 2. Tumor invasion into adjacent anatomic structures such as the sternothyroid muscle, surrounding soft tissues, trachea, esophagus, or laryngeal nerve. 3. History of neck trauma, previous tumor surgery, or adjuvant chemoradiotherapy. 4. Fewer than three lymph nodes dissected during surgery. 5. Concurrent acute inflammatory conditions or other hematologic disorders.