Visualization Methods for Uterine Sentinel Lymph Nodes in Early-Stage Endometrial Carcinoma: A Comparative Analysis

Abstract

Background: Sentinel lymph node (SLN) biopsy in early-stage endometrial cancer is recommended over systematic lymphadenectomy due to reduced morbidity and comparable detection rates. The main objective of this study was to compare the overall and bilateral detection rates of SLN in early-stage endometrial cancer using three techniques.

Methods: a prospective cohort study was designed to detect the difference in SLN detection rate in three cohorts: Indocyanine green (ICG), methylene blue (MB), and tracer combination (ICG + MB). Mapping characteristics, detection rate, number of SLNs, and positive SLNs of the three cohorts were compared.

Results: A total of 99 patients were enrolled. A total of 109 SLN sites with 164 lymph nodes were detected. No differences were found between the three cohorts in terms of age, BMI, tumor diameter, or other histologic characteristics. The overall SLN detection rate (DR) was 54.3% in the MB group, 72.7% in ICG, and 80.6% in the ICG-MB group. Bilateral DR was 22.9%, 39.4%, and 54.8% in groups, respectively, with the MB method yielding significantly inferior results.

Conclusions: The ICG-MB group demonstrated superior overall and bilateral detection rates, but a significant difference was found only in the MB cohort. Combining tracer agents can enhance the accuracy of SLN identification in initial-stage endometrial cancer without additional risk to the patient.

Keywords: endometrial cancer; endometrial carcinoma; sentinel lymph node biopsy; sentinel lymph node mapping.

Figure 1

(a) Image of uterine SLN traced with MB; (b) Image of uterine SLN traced with ICG (in ICG-MB combination). Both images were observed during laparoscopic surgery.

Figure 2

Sites for detecting SLNs (round shape) and metastases (triangular shape).