Indocyanine green guidance for combined robotic pelvic and para-aortic sentinel node mapping in cervical cancer

Abstract

BackgroundIndocyanine green (ICG) for pelvic sentinel lymph node (SLN) mapping is well established in endometrial cancer (Persson et al., 2019 Jul). However, the application for para-aortic SLNs is less reported; and the detection rate of para-aortic SLNs, mainly after cervical injection of ICG, varies between 14% and 71% (Rossi et al., 2013 Nov; Kim et al., 2020 Mar; Gallotta et al., 2019 Mar). One recent report differentiates between lower and upper para-aortic SLNs in endometrial cancer (Kim et al., 2020 Mar). Here we describe a technique using ICG for identifying pelvic SLNs, lower and upper para-aortic SLNs in cervical cancer. VideoA 46-year old female presented with high grade cervical dysplasia/carcinoma in situ on cervical smear. Cervical cone biopsy revealed a grade two squamous cell carcinoma (depth of invasion 6.8mm, width 20.8mm). Clinically she was staged as an early FIGO-stage IB2 cervical cancer. NMR revealed bilaterally enlarged iliac lymph nodes. Additional PET-CT revealed FDG-uptake in the enlarged pelvic lymph nodes. In view of the imaging findings a staging Robotic pelvic and para-aortic SLN procedure was planned, prior to select the primary treatment (radical hysterectomy or chemo-radiation). ICG was injected into the cervical stroma, and a robotic pelvic and para-aortic SLN dissection (using Firefly System ®, Intuitive Surgical Inc.) was initiated 15 minutes and 35 minutes, respectively, after cervical injection. ResultsThis video demonstrates the application of ICG for mapping bilateral primary pelvic SLNs, secondary and tertiary para-aortic SLNs in the lower and upper para-aortic region respectively, in cervical cancer. Pathology revealed one metastatic pelvic SLN on the left side, other four pelvic SLNs were negative; both the secondary/lower (n = 3) and tertiary/upper (n = 5) para-aortic SLNs were negative, as well as the non-SLNs (n = 8). ConclusionThe application of ICG for para-aortic SLN mapping should further be investigated and validated in staging surgically locally advanced cervical cancer and those with suspicious lymph nodes on imaging.