Does Retroperitoneal vNOTES Sentinel Lymph Node Mapping Represent a Feasible Staging Option in Presumed Early-Stage Endometrial Cancer?

Background and Objectives: Sentinel lymph node (SLN) mapping is an established alternative to systematic lymphadenectomy for early-stage endometrial cancer (EC). While retroperitoneal vNOTES affords direct access to pelvic nodes without abdominal incisions, data regarding its oncologic validity remain sparse. This study evaluates the SLN detection rates, perioperative outcomes, and 12-month oncologic outcomes oncologic results of retroperitoneal vNOTES mapping in presumed early-stage EC. Materials and Methods: This single-center retrospective cohort study analyzed consecutive patients undergoing retroperitoneal vNOTES staging (hysterectomy, BSO, and SLN mapping) for presumed EC between February 2023 and January 2024. Eligible patients had radiologically uterine-confined disease and were candidates for transvaginal surgery. Following cervical methylene blue injection, SLN mapping was executed via the retroperitoneal vNOTES route. Mapped and suspicious nodes were excised, with side-specific lymphadenectomy performed for failed mapping per algorithm. While perioperative outcomes were assessed for the full cohort, oncologic analyses (FIGO 2023 staging, nodal metastasis) were restricted to patients with confirmed carcinoma. Results: Of 98 patients (median age 54; BMI 31 kg/m2), final pathology confirmed carcinoma in 78 (73 endometrioid, 5 serous) and EIN in 20. Bilateral SLN mapping succeeded in 87.8% (86/98), necessitating side-specific lymphadenectomy in the remaining 12.2%. The obturator fossa was the predominant nodal basin (43.9%). Within the carcinoma cohort (n = 78), 57.7% were Grade 1 and 74.4% FIGO Stage I. Nodal metastases (FIGO IIIC1) were identified in 12.8% (10/78), all prompting adjuvant therapy. At a median follow-up of 12 months, no disease recurrences were observed. The complication rate was 6.1% (5.1% Clavien–Dindo ≥ III), with no conversions required. At 12-month follow-up, no recurrences were detected, though the absence of systematic lymphadenectomy precluded formal sensitivity analysis. Conclusions: Retroperitoneal vNOTES represents a feasible and safe strategy for SLN mapping in early-stage EC, demonstrating high bilateral detection with minimal morbidity. However, reliance on methylene blue and limited follow-up necessitate caution. Broader implementation requires validation through prospective, comparative trials utilizing indocyanine green and long-term oncologic surveillance.