Implementation of a New Surgical Technique in a Gynecologic Oncology Centre: Sentinel Lymph Node Biopsy and Its Learning Curve in Endometrial Cancer

Objectives: This study aimed to evaluate the introduction of sentinel lymph node biopsy (SLNB) in early-stage endometrial cancer (EC), its learning curve, and factors influencing discrepancies between surgeons and pathologists. Methods: A single-centre retrospective observational study was conducted from June 2019 to December 2024 at the Department of Obstetrics and Gynecology, University Hospital Brno and Faculty of Medicine, Masaryk University. Patients with EC with complete preoperative staging and planned for extrafascial hysterectomy with bilateral salpingo-oophorectomy and SLNB were included. Bilateral detection rates were compared among two main surgeons—one senior fellow (A) and one junior fellow (B)—and other supervised fellows. Learning curves were assessed using detection rates and cumulative sum analysis. Risk factors for failed detection were analysed. Results: In 337 patients, overall bilateral detection rates ranged from 80–92%. Surgeon A achieved 80% success by the 30th procedure and 89% at the 74th. Surgeon B, trained under A’s supervision, reached 89% but later showed a decline after operating independently. The highest concordance with pathologists was noted for Surgeon A (94.6%), followed by B (92.2%) and others (84.9%). Discrepancies were mainly associated with the presence of fibroids (p = 0.005) and adenomyosis (p = 0.018). Conclusions: SNB in EC demonstrates an optimal learning curve that can be shortened through expert guidance. Extending supervised training to 30–35 procedures reduces post-independence decline and sustains high detection rates. Bilateral success, reflecting surgeon–pathologist concordance, is a strong indicator of the quality of a Gynecologic Oncology centre.