Maximizing sentinel node detection in endometrial cancer with dual cervical and transcervical fundal indocyanine green injection: 5-year single-center prospective study.

Objective: The aim of this study was to describe our latest results using dual cervical and fundal indocyanine green injection for detection of sentinel lymph node (SLN) in endometrial cancer.

Methods: A prospective observational study was conducted between 26 June 2014 and 31 December 2019 with 278 patients that underwent laparoscopic surgery for endometrial cancer at our institution. In all cases, we performed SLN biopsy with dual cervical and fundal indocyanine green injection. All SLNs were processed with an ultrastaging technique. A total of 128 patients also underwent total pelvic and paraaortic lymphadenectomy.

Results: The detection rates were as follows: 93.5 % (260/278) overall for SLNs; 90.7 % (252/278) overall for pelvic SLNs; 68.0 % (189/278) for bilateral SLNs; 66.9 % (186/278) for paraaortic SLNs, and 2.9 % (8/278) for isolated paraaortic SLNs. We found macroscopic lymph node metastasis in 26 patients (10.0 %) and microdisease in lymph nodes in another 48 patients, raising the overall rate of lymph node involvement to 16.2 %. There was one false negative (negative SLN biopsy but positive lymphadenectomy). Applying the SLN algorithm, the sensitivity of detection was 97.9 % (95 % CI 89.1-99.6), specificity 100 % (95 % CI 98.2-100), negative predictive value 99.5 % (95 % CI 97.4-99.9), and positive predictive value 100 % (95 % CI 92.4-100).

Conclusions: Dual sentinel node injection is a feasible technique that achieves adequate detection rates. Additionally, this technique allows a high rate of aortic detection, identifying a non-negligible percentage of isolated aortic metastases. Aortic metastases in endometrial cancer are possible and we should not give up actively looking for them.