Introduction/Background The aim of this study is to assess outcomes of sentinel lymph node biopsy at our institution since its implementation in all risk groups and to evaluate factors associated with migration.

Methodology Retrospective cohort study including all newly clinical early-stage endometrial cancer cases operated between January 2021 and April 2022. Minimum preoperative work-up included endometrial biopsy with histomolecular information, transvaginal ultrasound and pelvic MRI. Toraco-abdominal TC was added in high-risk.

Results 56 cases were included. Sentinel node biopsy was done in 39/56 (69.6%). 11/56 with no nodal staging because of anaesthetic risk: 8 low/intermediate risk, 3 high-intermediate/high risk. In 5/56 (8.9%) lymphadenectomy was done: 2 were re-staging procedures, 1 for preoperative diagnosis of primary cervical cancer and 2 were excluded of sentinel node protocol due to antecedent of pelvic radiotherapy. Median BMI was 28.5 (IQR 25–35), age 65.5 y (IQR 57.0–73.0), operating time 145 min (IQR 126–170), and hospitalization time 2 days (IQR 2–3). Way of approach was robotic surgery in 94.6%. Between sentinel node patients, cervical injection and indocianine green were used in all cases. No intraoperative complications and 3/39 postoperative complications (Clavien-Dindo II) were reported. Overall detection rate was 92.3% and bilateral detection rate 74.3%. Side-specific lymphadenectomy was needed because of no detection and high-intermediate/high risk in 2/39. Reinjection of tracer was 20.5%. 63 nodes were detected, most frequent localization was external iliac 35/63 (55.5%). Overall positive nodes were 5.1%: macrometastasis in 1 case (preoperative low-risk) and micrometastasis in 1 case (preoperative intermediate-risk). No differences in bilateral detection were observed regarding age, BMI, comorbilities or molecular group.

Conclusion Sentinel lymph node biopsy is feasible in routine clinical practice with bilateral detection rates similar to that reported. Positive nodes were observed in low/intermediate risk and not only in high-risk patients so it cannot be omitted in these groups.