Five-Year Oncologic Outcome and Surgical Completeness of Transoral Robotic Thyroidectomy for Papillary Thyroid Carcinoma: Comparison with Conventional Transcervical Thyroidectomy Using Propensity Score Matching

Objective. This study aimed to evaluate the oncological outcomes and surgical completeness of transoral robotic thyroidectomy (TORT) for papillary thyroid carcinoma (PTC) compared with conventional transcervical thyroidectomy.Methods. We analyzed 489 patients with PTC who underwent thyroidectomy with or without central neck dissection (CND; 311 conventional thyroidectomy and 178 TORT) between January 2017 and December 2021. Patients with gross invasion of the surrounding structures, revision or completion thyroidectomy, and lateral neck dissection were excluded. Propensity score-matched analysis was performed using eight covariates, including age, sex, extent of thyroidectomy, tumor size, extrathyroidal extension (ETE), radioactive iodine (RAI) ablation, lymphovascular invasion (LVI), and CND.Results. Before propensity score matching (PSM), age, male-to-female ratio, and body mass index were lower in the TORT group. The ratio of total thyroidectomy and CND, tumor size and bilaterality, LVI, and RAI ablation were higher in the conventional group. PSM generated two matched groups of 100 patients each. After PSM, significant differences between the two groups in the baseline analysis disappeared. In the matched samples, the recurrence rate (2% and 0% in the conventional and TORT groups, respectively) and recurrence-free survival curves did not differ between the two groups. The mean thyroid stimulating hormone (TSH)-stimulated thyroglobulin level in the RAI group and TSH-suppressed thyroglobulin level in the non-RAI group were not different between the two groups.Conclusions. The 5-year oncologic outcomes and surgical completeness of TORT were comparable with those of conventional thyroidectomy in patients with small, localized, low-risk PTC when performed by experienced surgeons.