Cervical re-injection of indocyanine green to improve sentinel lymph node detection in endometrial cancer

Objectives: To evaluate the role of cervical re-injection of indocyanine green (ICG) to increase the detection rate of sentinel lymph node (SLN) in patients with endometrial cancer (EC) who underwent robotic-assisted surgical staging. Methods: We retrospectively identified consecutive EC patients undergoing robotic-assisted staging with SLN biopsy at our Institution between June 2016 and April 2020. Patients were excluded if they had open abdominal surgical approach, neoadjuvant chemotherapy, and advanced stage [International Federation of Gynecology and Obstetrics (FIGO) stage III-IV] at diagnosis. According to our SLN protocol, in case of either unilateral or no SLN detection, we performed an ipsilateral or bilateral cervical re-injection of ICG. Results: In total, 251 patients meeting inclusion criteria were included in the analysis. At first injection, bilateral detection was achieved in 184 (73.3%), unilateral detection in 57 (22.7%), and no detection in 10 (4.0%) patients. Cervical re-injection was performed in 51 of 67 patients with failed bilateral mapping. After cervical re-injection, bilateral detection rate increased to 94.5% (222/235), while unilateral and no detection were 5.1% (12/235) and 0.4% (1/235), respectively. Conclusions: Our results suggest that cervical re-injection of ICG, in case of failed bilateral mapping of SLN, brings about a significant improvement in SLN detection rates, therefore reducing the number of side-specific required lymphadenectomies.