Estimating the risk of completion total thyroidectomy using real-world data to guide initial surgical decision-making for patients with clinical low-risk papillary thyroid carcinoma

Background Continuing controversy exists in different guidelines’ recommendations regarding whether total thyroidectomy (TT) or lobectomy is the optimal surgery for patients with low-risk papillary thyroid carcinoma (PTC). Diverse perceptions of the risk of completion TT after lobectomy are the main debate between guidelines and institutions. Methods Patients who underwent thyroidectomy and prophylactic central lymph node dissection for ≤ 4 cm PTC (January 2007 to December 2020) by high-volume surgeons were included. Patients with preoperatively known high-risk characteristics or suspicious bilateral multifocality were excluded. The pathological findings were defined as the risk stratifications of completion TT from low to high to evaluate which initial surgical procedure could allow more patients to meet the criteria of optimal surgical extent. Results Of 4965 consecutive patients met lobectomy criteria as the initial operation. Aggressive histological subtypes were found in 2.5% of patients, T3b disease in 1.1%, T4 disease in 3.1%, LNs involved ≤ 5 in 29.5%, LNs involved > 5 in 3.1%, and incidental bilateral multifocality in 7.9%. According to our defined risk stratification system, TT and lobectomy would be considered the optimal initial procedure in 12.0% and 67.2% PTC patients with a tumor ≤ 1 cm and 28.7% and 36.6% in the 1–4 cm groups in our real-world cohort, respectively. Conclusion Lobectomy alone, as an initial procedure, could allow more low-risk PTC patients with a tumor either ≤ 1 cm or 1–4 cm to achieve the optimal surgical extent. Moreover, surgeons should balance the high-risk characteristics and complication risks during surgery to re-evaluate surgical decision-making.