Sentinel Lymph Node Mapping Compared with Selective Lymph Node Sampling in the Surgical Staging of Endometrial Cancer: A Prospective Observational Study

Background/Objectives: Nowadays, lymph node assessment represents a key component in the surgical staging of endometrial cancer, as sentinel lymph node (SLN) mapping increased in adoption as an alternative to lymphadenectomy. This study aimed to compare SLN mapping and selective lymph node sampling (SLNS) in endometrial cancer cases managed in a tertiary oncologic center. Moreover, the study evaluated clinicopathological characteristics and the association between tumor stage and nodal involvement. Methods: This prospective observational cohort study included 137 patients with histologically confirmed endometrial cancer who underwent surgical staging between January 2020 and August 2025. Either SLN mapping using indocyanine green (ICG) or methylene blue (blue dye–BD) or SLNS was performed during the surgery. Clinical, surgical, and histopathological data were analyzed using descriptive and inferential statistics. Results: SLN mapping was performed in 86 patients (BD: 45; ICG: 41), while the other 51 underwent SLNS. Median lymph node yield was significantly higher in the SLNS group (10 nodes) in comparison to SLN mapping (four nodes for both BD and ICG; p < 0.001). The overall nodal metastasis rate was 9.5%, with no significant difference between techniques (SLNS: 9.8%, BD: 8.9%, ICG: 9.8%; p = 0.99). Bilateral nodal detection rates were higher in the BD group compared to the ICG group (73.3% vs. 51.2%; OR = 2.62, p = 0.045). Nodal involvement increased significantly in parallel with advancing pathological T stage (p < 0.001), ranging from 0% in T1a to 40.0% in T3a disease. Conclusions: Even though SLNS resulted in a higher number of lymph nodes retrieved, SLN mapping demonstrated similar observed rates of nodal metastases across groups within the limits of this observational study. BD demonstrates superior bilateral detection rates compared to ICG in this cohort. Tumor stage remains a predictor of lymph node involvement. All these findings justify the use of SLN mapping as an effective staging strategy in patients with endometrial cancer.