Introduction/Background Sentinel node (SN) biopsy is a safe staging method in patients with Vulva Cancer (VC). Near-infrared fluorescence (NIRF) imaging using indocyanine green (ICG) has recently been introduced. The purpose of this study was to evaluate the feasibility and safety of NIRF imaging for SN detection in conjunction with conventional radio-guided technique.

Methodology Patients with primary VC, unifocal tumor < 4 cm with no suspicious nodes were included in this prospective observational single-center study. Bimodal tracer (ICG-99mTc-Nanocoll) was injected peritumorally and followed by lymphoscintigraphy. Intraoperatively SNs were detected with a hand-held gamma-probe and NIRF camera. The primary outcome was SN detection rate per groin and per patient. Patients were followed from date of inclusion to Jan 26th2022.

Results SN procedure was performed in 100 patients (36 uni- and 64 bilaterally) with primary vulvacancer, corresponding to 164 groins. The overall SN detection rate per patient was 97%. In 36 patients with lateralized tumor the SN detection rate perioperatively was 97.2%. In 64 patients with midline tumors the bilateral detection rate perioperatively was 81.3%, and the overall detection rate was 96.9%. Twenty-one patients had SN metastases (stage III A-C) while 79 patients were node negative (stage IB). Median follow up was 20.4 month (range 2–47.8). 73% of patients had more than one and 41% of patients had more than two years follow-up. During follow-up 10 patients developed recurrence (in vulva (n=4), groin (n=1), vulva and groin (n=4) and distant metastases (n=1)). The isolated groin recurrences occurred in one patient with bilaterally SN-negative groins. The two years disease free survival and overall survival was 93.0% and 95.2%., respectively.

Conclusion A combination of fluorescent and radioactive technique using ICG-99mTc-Nanocoll for detection of SN is feasible and a safe treatment option for patients with clinically low stage vulvacancer.