88 Cervical re-injection to improve sentinel lymph node detection in endometrial cancer

Objectives To evaluate the impact of cervical re-injection on the detection rate of fluorescence-guided sentinel lymph node (SLN) mapping in endometrial cancer (EC) patients undergoing robotic-assisted surgical staging. Methods From April, 1 2017 to December, 31 2018 patients undergoing robotic-assisted surgery for apparently early-stage EC at our Institution were prospectively treated with SLN mapping using indocyanine green (ICG) accordingly to the Memorial Sloan Kettering Cancer Center (MSKCC) surgical algorithm. As per MSKCC algorithm, four mL (1.25 mg/mL) of ICG were injected into the cervical submucosa and stroma, at the 3 and 9 o’clock positions (1 mL each). In case of either no detection or unilateral detection, cervical re-injection was performed followings the same steps as previously described. Overall (successful mapping of at least one hemipelvis) and bilateral detection were evaluated pre- and post-re-injection. Results Of the 107 patients undergoing robotic-assisted surgical staging for EC during the study period, 7 cases with no detection or unilateral detection who did not underwent re-injection were excluded. Among the remaining 100 patients, after a single injection the overall detection rate was 98% (95% CI, 92.2–99.6%) with a 69% (95% CI, 58.8–77.7%) of bilateral detection rate. After re-injection, overall and bilateral detection rate were 100% (95% CI, 95.3–100%) and 91% (95% CI, 8.32–95.5%), respectively. Conclusions In the case of no detection or unilateral sentinel lymph node detection, cervical re-injection of ICG can increase overall and bilateral detection rate, thus decreasing the number of patients requiring a complete bilateral or side-specific lymphadenectomy.