Introduction/Background*In the primary treatment of stage I intermediate risk and high-intermediate risk endometrial cancer (EC) sentinel lymph node biopsy (SLN) can be considered for staging. Although there is no prospective trials for assessment the oncological outcome in these groups.

Study hypothesis we hypothesize that progression-free survival in women who underwent biopsy of mapping sentinel lymph node with indocyanine green will be not inferior compared to the patients in which systematic lymph nodes dissection will be performed.

Methodology Trial design:This prospective, randomized, non-inferiority study is to evaluate progression-free survival in patients with endometrioid EC with stage I from the intermediate and high-intermediate risk groups, who will have been performed SLN biopsy and systemic lymphadenectomy (pelvic and para-aortic lymph nodes dissection).

Inclusion criteria: 1.histological confirm endometrioid cancer of endometrium. 2. intermediate and high-intermediate risk (grade 1, grade 3 with ≥50% myometrial invasion, grade 3 with <50% myometrial invasion).

Exclusion criteria: 1. low risk (G1 with with <50% myometrial invasion), 2. other histological tumor variant except for endometrioid.

Result(s)* Primary endpoint: 1. Progression-free survival in patients with isolated tumor cells 2. Quality of life by EORTC QLQ-C30 and LYMQOL-Leg scales 3. 30-day post-surgery complications by Clavien-Dindo scale 4. overall survival rate which is defined from the moment of randomization to death (any cause); alive patients are analyzed after acquisition of the last information

Secondary endpoints: progression-free survival in patients with endometrioid stage I intermediate and high-intermediate risk endometrial cancer

Sample size: 430 patients for study cohort

Conclusion*Estimated Dates for Completing Accrual and Presenting Results : the study will be completed in 2023 with results in 2026

Trial Registration Number of local ethical protocol in Ukraine – №163 (23.06.20)

Disclosures Authors declare no disclosures.