Sentinel node mapping with indocyanine green and endoscopic near-infrared fluorescence imaging in endometrial cancer. A pilot study and review of the literature

Objectives: Indocyanine green (ICG) with near-infrared (NIR) fluorescence imaging is a new tracer modality used for lymphatic mapping. We report our initial experience with ICG for SLN mapping in cervical and endometrial cancer using a new endoscopic fluorescence imaging system.

Methods: We reviewed all patients who underwent primary surgery for early-stage endometrial and cervical carcinoma with SLN mapping using fluorescence imaging followed by pelvic lymphadenectomy from February to July 2014. Intracervical injection of ICG at 3 and 9 o'clock was performed in all cases. SLNs were ultrastaged on final pathology. Sensitivity and specificity values were calculated.

Results: A total of 50 patients were included in the study (42 endometrial and 8 cervical cancers). The median age was 62 (24-88) and median BMI 29 (19-56). The median SLN count was 3.1 (0-7) and median lymph node count was 15 (2-37). The overall and bilateral detection rate was 96% (48/50) and 88% (44/50). Positive SLNs were identified in 22% of patients (11/50), including 8 isolated tumor cells (ITC), 2 micrometastasis and 1 macrometastasis. There was one side-specific false negative case. Sensitivity, specificity and NPV were 93.3%, 100% and 98.7% respectively per side. Paraaortic node dissection was performed in 22% of cases. Two had paraaortic node metastasis both in patients with positive pelvic SLN. There were no allergic reactions to the ICG.

Conclusions: Based on our pilot experience, NIR fluorescence imaging with ICG is an excellent and safe tracer modality for SLN mapping with a very high overall (96%) and bilateral (88%) detection rate.