Advanced Age as a Predictor of Unsuccessful Bilateral Sentinel Lymph Node Detection Using Radiocolloid Mapping in Patients With Endometrial Cancer: A Prospective Observational Study

TL;DR

Older age is linked to lower success in detecting sentinel lymph nodes in endometrial cancer patients using a radiocolloid method.

Contribution

This study identifies advanced age as an independent predictor of unsuccessful bilateral sentinel lymph node detection in endometrial cancer.

Findings

The bilateral sentinel lymph node detection rate was 83.4% in the study population.

Advanced age was a significant independent predictor of unsuccessful detection (OR = 1.057).

Abstract

Objective: To identify clinical and pathological factors associated with unsuccessful bilateral sentinel lymph node (SLN) detection using the technetium-99m-labeled phytate radiocolloid method (RI method) in patients with endometrial cancer.

Methods: This prospective observational study included 223 patients with histologically confirmed presumed early-stage endometrial cancer who underwent SLN mapping between July 2018 and May 2022 at Kagoshima University Hospital. A radiocolloid tracer was injected into the cervix the day before surgery, followed by preoperative single-photon emission computed tomography combined with computed tomography imaging. The SLNs were intraoperatively localized using a gamma probe and assessed via frozen sections or one-step nucleic acid amplification. Bilateral SLN detection was defined as successful localization of at least one SLN in each hemipelvis. Multivariate logistic regression was used to identify the independent predictors of detection failure.

Results: The overall bilateral SLN detection rate was 83.4% (186/223). In the univariate analysis, advanced age (median 63.0 vs. 58.0 years, p = 0.0003) and myometrial invasion ≥50% (p = 0.0289) were associated with unsuccessful detection. In the multivariate analysis, age was a significant independent predictor (OR = 1.057, 95% CI: 1.017-1.099, p = 0.0037), whereas other variables, including body mass index, histological type, lymphovascular space invasion, and cervical stromal invasion, were not.

Conclusions: Advanced age significantly increased the risk of unsuccessful bilateral SLN detection using the RI method for endometrial cancer. These findings emphasize the need for individualized surgical planning in older patients, including preoperative counseling and consideration of adjunctive strategies to improve detection rates, particularly in cases in which alternative tracers, such as indocyanine green, are not reimbursed.