Impact of tumor size on oncological and surgical outcomes in robot-assisted transaxillary surgery for papillary thyroid carcinoma.

[BACKGROUND] Robot-assisted transaxillary thyroidectomy (RATT) has emerged as a remote access approach for differentiated thyroid carcinoma (DTC), yet data on its oncological efficacy for tumors larger than 3 cm, particularly in European cohorts, remain scarce. This study aimed to evaluate surgical and oncological outcomes of RATT in patients with papillary thyroid carcinoma (PTC), stratified by tumor size.

[MATERIALS AND METHODS] We retrospectively reviewed 270 patients with histologically confirmed PTC who underwent RATT between July 2012 and August 2022 at a single tertiary center. Patients were categorized into two groups based on tumor size: Group A (<3 cm, n = 226) and Group B (≥3 cm, n = 44). Surgical outcomes, complication rates, and oncological parameters-including serum thyroglobulin (Tg) levels, anti-thyroglobulin antibodies, and structural recurrence-were analyzed. Subgroup analysis was conducted based on radioiodine ablation (RAI) status.

[RESULTS] No significant differences were observed between groups in terms of operative time, hospital stay, or postoperative complications. Tg levels after RAI were comparable between Group A and Group B (p = 0.999), indicating similar biochemical response. Only one patient experienced structural recurrence during follow-up (mean: 48 ± 31 months). Patients who underwent lobectomy alone showed no evidence of recurrence regardless of tumor size. No independent predictors of Tg levels were identified.

[CONCLUSIONS] RATT appears to be a safe and oncologically effective approach for PTC, even for tumors ≥3 cm. These findings support the broader use of RATT in selected patients, with outcomes comparable across tumor sizes. Further multicenter studies with longer follow-up are warranted to validate these results.