Application of Indocyanine Green in the Detection of Sentinel Lymph Nodes in Laparoscopic Staging Surgery for Endometrial Cancer: A Retrospective Cohort Study.

Abstract

Objectives: Indocyanine green (ICG) sentinel lymph node (SLN) mapping has been used in endometrial cancer. We aimed to report our experience in the lymph node detection rate, negative predictive value (NPV), distribution, and risk factors of laparoscopic ICG SLN mapping in patients with endometrial cancer.

Materials and methods: We retrospectively analyzed patients with endometrial cancer who underwent laparoscopic staging surgery with ICG SLN mapping between January 2019 and July 2023. Thirty-one patients were included. ICG was injected into the cervix at 2-4 points. The outcomes were detecting and mapping failure rates and subsequent adjuvant therapy. Kruskal-Wallis and Chi-square tests were used for continuous and categorical variables. Statistical significance was set at P < 0.05.

Results: The overall detection rate of SLN was 80.6% (25/31). Both NPV and sensitivity were 100%. Bilateral SLN was detected in 52% (13/25) of cases. The right and left sides were visualized in 84% (21/25) and 68% (17/25) cases, respectively. Complete pelvic lymph node dissection was done when SLN mapping failed. The most common SLN locations were the right and left external iliac regions. SLN detection in the para-aortic area was observed in 20% (5/25) cases. Twenty-five patients had positive SLN mapping. Two patients (8%) had positive lymph node metastasis: one underwent bilateral pelvic sentinel lymphadenectomy plus para-aortic sentinel lymphadenectomy with the final histologic type of Grade 2 endometrioid carcinoma (Stage IIIC1), and the other underwent bilateral pelvic lymphadenectomy with the final histologic type of serous carcinoma (Stage IIIC1). Sixteen patients had high-grade stage IA or above; five received postoperative adjuvant chemotherapy, five received postoperative radiotherapy, four received chemotherapy with radiotherapy, and two were followed up.

Conclusion: The NPV and sensitivity of ICG application in our study were high. The metastatic status of the lymph nodes is important for future therapeutic planning for advanced endometrial cancer.