Sentinel lymph node biopsy with cervical injection of indocyanine green in apparent early-stage endometrial cancer: predictors of unsuccessful mapping

Objective: To identify predictors of unsuccessful sentinel lymph node (SLN) mapping in patients with apparent early-stage endometrial cancer (EC) undergoing surgical staging with cervical injection of indocyanine green and SLN biopsy. Methods: We retrospectively identified consecutive patients with EC with attempted SLN biopsy between June 2014 and June 2016 at our institution. Patients were grouped according to whether they had a successful procedure, defined as the bilateral identification of SLNs, or an unsuccessful procedure, defined as unilateral or no SLN mapping. Logistic regression was used to evaluate predictors of an unsuccessful procedure. Results: Among 327 patients included in the analysis, 256 (78.3%) had a successful procedure and 71 (21.7%) had an unsuccessful procedure (15.0% unilateral SLN mapping, 6.7% no mapping). The rate of successful procedure increased from 57.7% to 83.3% between the first and last quarters of the 2-year study period, which represented the learning curve for the technique. The mean (SD) operative time decreased from 164 (55) to 137 (37) minutes. By multivariable analysis, lysis of adhesions at the beginning of surgery (odds ratio, 3.07; 95% CI, 1.56–6.07) and the presence of enlarged lymph nodes (odds ratio, 4.69; 95% CI, 1.82–12.11) were independently associated with an unsuccessful procedure. Conclusions: Lysis of adhesions at the beginning of surgery and the presence of enlarged lymph nodes independently affect the bilateral detection of SLNs.