Near-infrared fluorescence imaging compared to standard sentinel lymph node detection with blue dye in patients with vulvar cancer – a randomized controlled trial

Marion M Deken,Helena C Van Doorn,Danielle Verver,Leonora S.F Boogerd,Kim S De Valk,Daphne D.D Rietbergen,Mariëtte I.E Van Poelgeest,Cor D De Kroon,Jogchum J Beltman,Fijs W.B Van Leeuwen,Hein Putter,Jeffrey P.B.M Braak,Lioe-Fee De Geus-Oei,Cock J.H Van De Velde,Jacobus Burggraaf,Alexander L Vahrmeijer,Katja N Gaarenstroom

doi:10.1016/j.ygyno.2020.09.044

Abstract

ObjectiveThe aim of this study was to assess the superiority of ICG-99mTc-nanocolloid for the intraoperative visual detection of sentinel lymph nodes (SLNs) in vulvar squamous cell carcinoma (VSCC) patients compared to standard SLN detection using 99mTc-nanocolloid with blue dye. MethodsIn this multicenter, randomized controlled trial, VSCC patients underwent either the standard SLN procedure or with the hybrid tracer ICG-99mTc-nanocolloid. The primary endpoint was the percentage of fluorescent SLNs compared to blue SLNs. Secondary endpoints were successful SLN procedures, surgical outcomes and postoperative complications. ResultsForty-eight patients were randomized to the standard (n = 24) or fluorescence imaging group (n = 24) using ICG-99mTc-nanocolloid. The percentage of blue SLNs was 65.3% compared to 92.5% fluorescent SLNs (p < 0.001). A successful SLN procedure was obtained in 92.1% of the groins in the standard group and 97.2% of the groins in the fluorescence imaging group (p = 0.33). Groups did not differ in surgical outcome, although more short-term postoperative complications were documented in the standard group (p = 0.041). ConclusionsIntraoperative visual detection of SLNs in patients with VSCC using ICG-99mTc-nanocolloid was superior compared to 99mTc-nanocolloid and blue dye. The rate of successful SLN procedures between both groups was not significantly different. Fluorescence imaging has potential to be used routinely in the SLN procedure in VSCC patients to facilitate the search by direct visualization.Clinical Trial Registration: Netherlands Trial Register (Trial ID NL7443).

Highlights

The sentinel lymph node (SLN) procedure has been proven to be a reliable and safe method in patients with early-stage vulvar squamous cell carcinoma (VSCC) [1,2,3]
For unifocal VSCCs, with a diameter of 4 cm or less and without suspected or enlarged groin lymph nodes, the current standard treatment consists of a radical local excision of the tumor and a SLN procedure, ipsilateral or bilateral depending on location of the vulvar tumor and outcome of lymphoscintigraphy [1,2,3,4,5]
Standard SLN detection in vulvar cancer patients consists of a preoperative peritumoral injection with 99mTc-nanocolloid as a radiotracer, preoperative lymphoscintigraphy and the intraoperative use of radioguidance and additional blue dye for visual imaging [2,3,4,5]

Summary

Introduction

The sentinel lymph node (SLN) procedure has been proven to be a reliable and safe method in patients with early-stage vulvar squamous cell carcinoma (VSCC) [1,2,3]. Standard SLN detection in vulvar cancer patients consists of a preoperative peritumoral injection with 99mTc-nanocolloid as a radiotracer, preoperative lymphoscintigraphy and the intraoperative use of radioguidance and additional blue dye for visual imaging [2,3,4,5]. Metaanalyses show that the overall SLN detection rate with the combined use of 99mTc-nanocolloid and blue dye is 87–93% per groin [4,6] and 98% per patient [5,6]. In more than 30% of the cases, the surgeon has to rely solely on the guidance by the gamma probe to identify the SLN. This is associated with increased acute and late morbidity such as wound dehiscence, infection, lymphocele formation and lymphedema [2,7,8]

Methods

Results

Conclusion