Robotically assisted fluorescence-guided lymph node mapping with ICG for gynecologic malignancies: A feasibility study

Abstract Objective Traditional techniques of sentinel lymph node (SLN) mapping for endometrial and cervical cancer present challenges which may be overcome with newer technologies such as near infrared (NIR) imaging of the fluorescent dye Indocyanine green (ICG). We performed a feasibility and dose-finding study to define the dose of ICG required to identify pelvic and para-aortic sentinel lymph nodes with robotically assisted endoscopic NIR imaging after cervical injection. Methods 20 subjects with cervical or endometrial carcinoma were prospectively enrolled for SLN mapping. ICG was injected into the cervical stroma at 3 o'clock and 9 o'clock Data was collected for the number of nodes identified, the location of SLN's, the duration of procedure and the pathology characteristics of the SLN's compared to the non-sentinel lymph nodes. Results 20 subjects received cervical injection with at least one SLN observed in 17 subjects. 15 of the 17 subjects who received 1 mg injections of ICG mapped a SLN for an observed detection rate of 88% (95% CI is (64%,99%)). A median of 4.5 SLN's was identified per patient. Three patients had lymphatic metastases, one of whom had a positive SLN. No adverse events were identified. Conclusions A 1 mg cervical injection of ICG identified a SLN in 88% of patients (95% CI is (64%, 99%)). Robotically assisted fluorescence imaging is a feasible, safe, time efficient and reliable method for lymphatic mapping in early stage cervical and endometrial cancer.