Introduction/Background Sentinel node biopsy (SNB) has become the standard method for nodal staging in early-stage endometrial cancer. Detection rate is a surgical quality indicator and minimizing cases with no detection is important to improve outcomes.

The aim of this study is to assess outcomes of SNB and to evaluate causes of no detection.

Methodology Retrospective cohort study including all newly clinical early-stage endometrial cancer cases operated between January 2021 and December 2022 at Trueta University Hospital. When SNB was done, cervical injection and indocyanine green were used.

Results 82 cases were included. SNB was done in 56/82 (68.3%). 19/82 with no nodal staging because of anaesthetic risk, and 7/82 lymphadenectomy was done because of re-staging procedures or contraindications to SNB.

In sentinel node group, median BMI was 30.0 (IQR 25–35), operating time 145 min (IQR 130–164), and hospitalization time 2 days (IQR 2–2). No intraoperative complications and 2/56 postoperative complications (Clavien-Dindo II) were reported. Way of approach was robotic surgery in all cases.

Overall detection rate was 92.9%, bilateral detection rate was 76.8%, and reinjection of tracer was 17.9%.

Between cases of bilateral detection, 14% of them were due to reinjection. When no bilateral detection was found, in 6/13 (46.1%) there was some kind of extravasation of dye, and in 6/13 no detection although reinjection of tracer.

No differences in bilateral detection were observed regarding molecular group, lymphovascular invasion, BMI or age.

Overall positive nodes were 7.1%: macrometastasis in 3 cases (1 preoperative low-risk and 3 high-risk) and micrometastasis in 1 case (intermediate-risk).

Conclusion SNB is feasible in routine clinical practice with bilateral detection rates like that reported. Although reinjection of tracer can rescue some cases to bilateral detection, extravasation of dye constitutes a main reason for no detecting nodes. We cannot identify any factor associated with absence of migration in our cohort.

Disclosures Any.