Sentinel lymphadenectomy in cervical cancer using near infrared fluorescence from indocyanine green combined with technetium-99m-nanocolloid

Abstract

Objective: Sentinel diagnostic in cervical cancer is performed using Technetium-99m-nanocolloid as a radioactive marker with or without patent blue. In the last years, indocyanine green has been evaluated for sentinel diagnostic in different tumor entities. Indocyanine green is a fluorescent molecule which emits a light signal in the near infrared band after excitation. Our study aims to evaluate indocyanine green compared to the gold standard Tc-99m-nanocolloid.

Materials and methods: We included patients with early cervical cancer up to FIGO stage IIA with clinically node-negative pelvic sites and the indication for nodal staging in this prospective trial. Sentinel diagnostic was carried out using Tc-99m-nanocolloid, indocyanine green and patent blue. We examined each pelvic site for light signals from the near infrared band, for radioactivity and for blue staining. A sentinel lymph node was defined as a Tc-99m-nanocolloid positive lymph node. All sentinel lymph nodes and all additional blue or fluorescent lymph nodes were excised and tested; then sent to histologic examination.

Results: Thirty-three patients were included in which we found 211 Tc-99m-nanocolloid-positive sentinel lymph nodes in 66 pelvic sites. Two hundred and seven of these lymph nodes were positive for indocyanine green, too, giving a sensitivity of 98.1% (95%CI 94.9-99.4%) compared to Tc-99m-nanocolloid. One hundred and sixty additional lymph nodes showed indocyanine green fluorescence but no Tc-99m-positivity, so that the sensitivity was 79.6% (95%CI 76.6-82.3%). In one patient, a pelvic site was only identified to be tumor infiltrated due to an ICG-positive, but Tc-99m-negative lymph node.

Conclusion: Our results show that indocyanine green is a promising approach for pelvic sentinel identification in cervical cancer. ICG has a similar sensitivity as radioactive Tc-99m-nanocolloid and may enhance both patient safety and surgeons' comfort. Lasers Surg. Med. 50:994-1001, 2018. © 2018 Wiley Periodicals, Inc.

Keywords: cervical cancer; indocyanine green; near infrared detection; sentinel lymph node; technetium-99m.