The role of ultrastaging in sentinel lymph node biopsy with ICG mapping in endometrial cancer

BACKGROUND: Endometrial cancer is the most common malignancy of the female reproductive system, typically diagnosed at an early stage. Currently, one of the most widely used methods for sentinel lymph node mapping and biopsy in stage I endometrial cancer is indocyanine green (ICG) mapping followed by ultrastaging. AIM: The work aimed to evaluate the feasibility and optimal approach to ultrastaging of sentinel lymph nodes after ICG mapping across different risk groups for lymphatic metastasis in stage I endometrial cancer. METHODS: A cohort study included 286 patients with confirmed stage cT1a–T1bN0M0 endometrial cancer treated at the Department of Oncogynecology No. 70, Moscow S.P. Botkin Multidisciplinary Clinical and Research Center, and at the Kaluga Regional Clinical Oncological Dispensary between 2023 and 2024. All patients underwent sentinel lymph nodes biopsy with ICG mapping using indocyanine green, followed by ultrastaging. RESULTS: Bilateral sentinel lymph nodes detection rate was 70.9%. The incidence of N1 disease was 3.6% in the low-risk group, 12.8% in the intermediate-risk group, and 21.3% in the high-risk group. There was a trend toward increasing proportions of macrometastases as the risk increased from low to high. Metastatic involvement identified solely by immunohistochemistry accounted for 28.3%. CONCLUSION: Sentinel lymph nodes biopsy is feasible across all risk groups for lymphatic metastasis except in patients at high risk, who, according to the 2023 FIGO endometrial cancer classification, would be assigned to stage II disease. In this cohort, complete lymphadenectomy is recommended.