The use of indocyanine green (ICG) for sentinel lymph node detection in vulvar cancer

The aim of this study is to evaluate the use of indocyanine green (ICG) as a detection modality in sentinel lymph node (SLN) procedures for vulvar cancer.

A retrospective cohort study was performed from January 2008-August 2022 including all patients who underwent a SLN procedure for ≤4 cm vulvar cancer tumors with clinically/radiological normal inguinal nodes. SLN procedures with Tc99 +/- blue dye were compared to those with ICG +/- Tc99. Patient and tumor characteristics were collected as well as short-term and long-term complications. A subset analysis of SLN procedures with ICG alone was described.

A total of 229 patients were included, representing 365 groins. Detection modality was Tc99 +/-blue dye in 189 patients (304 groins) and ICG +/-Tc99 in 40 patients (60 groins). The SLN detection rate for Tc99 +/- blue dye was 93.4 % and for ICG +/- Tc99 90.3 % (p = 0.4). The SLN was positive in 17.3 % of the Tc99 +/- blue dye group vs 23.2 % in the ICG +/- Tc99 group (p = 0.3). There was no significant difference in short- or long-term complications. The detection rate among 15 patients (22 groins) where ICG was used as a single modality was 90.9 %. There were no specific patient or tumor characteristics related to SLN mapping failure.

The use of ICG +/- Tc99 as detection modality shows promising results with a success rate comparable to Tc99 +/- blue dye, supporting the use of ICG. Future studies are needed to confirm the efficacy and long-term safety of ICG alone.