Successful bilateral sentinel lymph node mapping rate and empty nodal packet rate in uterine cancer

To determine factors impacting successful bilateral sentinel lymph node mapping and empty nodal packet rate using indocyanine green for uterine cancer staging.

All women with clinical early-stage uterine cancer who underwent hysterectomy with sentinel lymph node mapping between January 1, 2014, and December 31, 2022, were included. The primary endpoint was the successful bilateral sentinel lymph node mapping rate. Secondarily, we assessed the empty nodal packet rate and identified factors impacting successful sentinel lymph node mapping and empty nodal packet rates. Appropriate statistical tests were used.

A total of 2690 patients were included, with a median body mass index of 30.9 kg/m² (range; 14.0-70.2). Of these, 1893 (70%) had low-grade endometrioid histology, 260 (10%) had high-grade endometrioid histology, and 537 (20%) had non-endometrioid histology. A total of 2499 (93%) cases were completed with minimally invasive surgery, and 191 (7%) via laparotomy. Bilateral sentinel lymph node mapping was successful in 2340 of 2690 patients (87%). The rate of bilateral mapping by body mass index group was 89% for body mass index <30 kg/m², 86% for body mass index 30 to 39.9 kg/m², 85% for body mass index 40 to 49.9 kg/m², 83% for body mass index 50 to 59.9 kg/m², 69% for body mass index ≥60 kg/m² (p =.04). A total of 2196 (88%) minimally invasive surgery cases had bilateral mapping compared with 144 (75%) laparotomy cases (p <.001). On multi-variate analysis, age, body mass index, and surgical approach were independently associated with successful sentinel lymph node mapping. Empty nodal packets occurred in 98 of 2633 patients (3.7%). Increasing age and body mass index were associated with a higher empty nodal packet rate. Bilateral mapping increased from 82.5% in 2014 to 91.3% in 2022 (p =.03), whereas the empty nodal packet rate did not change (p =.2).

High rates of successful sentinel lymph node mapping can be achieved across body mass index categories using indocyanine green. A decreased rate was noted in patients with body mass index ≥60 kg/m² and in cases completed via laparotomy. Sentinel lymph node mapping success rates improved with continued experience.