Background
Sentinel lymph node detection and biopsy enables detection of nodal disease without the risks of pelvic lymphadenectomy. This video will demonstrate how the sentinel node is identified using a fluorescent dye known as Indocyanine Green (ICG) and a near-infrared camera in a patient with endometrial cancer. This highlights the improved visualisation of the anatomy and lymphatic drainage in the pelvic sidewall.
Systematic pelvic lymphadenectomy has been associated with increased morbidity including lymphocyst formation, lymphoedema in up to 20% of women, and varying degrees of both short and long-term neuralgia and has not been shown to improve survival; therefore in Australia a complete node dissection in most patients is avoided even when the risk of nodal involvement remains.
Sentinel lymph node (SLN) mapping decreases morbidity and optimizes the pathologic assessment of identified nodes in women with endometrial cancer. Furthermore it increases the detection of lymphatic metastases, which can be present in up to 5% of women, when compared to staging lymphadenectomy [1], and, is associated with significantly lower blood loss and shorter operating time [2].
Method
High definition stereoscopic camera connected to a 0°/30° 10 mm scope equipped with a specific lens and light source emitting both visible and near infra-red (NIR) light is used. The cervix is injected after routine preparation and draping of the patient at positions 3 and 9 o’clock using 2ml of ICG solution (0.5mg/ml) to each side. Following this the laparoscopic procedure will follow with the expectation that the nodes should be visible within 10-15 minutes of the injection.
Results
A SLN algorithm is now included in the NCCN Guidelines for Endometrial Carcinoma with category 3 evidence [3,4]. The reported detection rate of SLNs with ICG is reported to be up to 97% [3]. Unilateral SLN detection rates with ICG have been reported at 100% with sensitivity and specificity reported between 93.7% and 100% [2].
Conclusion
SLN mapping using ICG will lead to a better informed decision-making process regarding adjuvant therapy, significantly lower short- and long-term morbidity, and decreased risk of both positive undiagnosed and untreated pelvic lymph nodes and overtreating of pelvic nodes which are suspected but clear of cancer.