Comparison of tracer application methods for sentinel lymph node detection in open surgery patients with endometrial cancer: a retrospective cohort study.

Background: This study aimed to evaluate the effectiveness of different tracers´ application techniques for sentinel lymph node (SLN) detection in women with endometrial cancer undergoing laparotomy. Additionally, potential risk factors for SLN detection failure were assessed.

Methods: We retrospectively analyzed data from 248 endometrial cancer patients who underwent abdominal surgery with SLN mapping between January 2020 and March 2024. Statistical analyses were conducted using the Wilcoxon rank sum test for continuous variables and either Pearson's chi-square test or Fisher's exact test for categorical variables, with a significance level set at p < 0.05.

Results: Group I + S consisted of 147 women with intracervical and subserosal tracers´application and group I + I included 101 women with intracervical and intrafundal application. Successful detection of SLN on both sides was achieved in 39.9% (99/248) of all patients, in 38.1% (56/147) in the I + S group and in 42.6% (43/101) in the I + I group, respectively. SLNs were identified in 32.7% (81/248) of all patients on only one side of the pelvis, in 31.3% (46/147) in the I + S and in 34.7% (35/101) in the I + I group, respectively. No SLNs were detected in 27.4% (68/248) of all subjects, comprising 30.6% (45/147) from the I + S and 22.8% (23/101) from the I + I group. Although the success rate of SLN detection was higher in the I + I group and on the right side of the pelvis regardless of the detection method, these differences were not statistically significant. An age exceeding 66.3 years was recognized as a critical risk factor for successful detection, other followed factors did not demonstrate a statistically significant impact on overall detection success. Additional significant risk factors were identified: depth of tumor myometrial invasion on the right side, history of pelvic surgery, and total tumor volume on the left side.

Conclusions: The study did not reveal significant differences in SLN mapping success between the groups receiving intracervical + intrafundal and intracervical + subserosal tracers´applications among endometrial cancer patients treated via open surgery. Overall, older age emerged as the most critical risk factor for SLN detection failure, while other assessed factors did not show a statistically significant impact on overall detection success.

Trial registration: Institution University Hospital Královské Vinohrady, Prague, Czech Republic.

Registration number: EK-VP-21-0-2023. Date of registration 7-JUN-2023. This study was retrospectively registered in compliance with the Declaration of Helsinki.