A novel system for analyzing indocyanine green (ICG) fluorescence spectra enables deeper lung tumor localization during thoracoscopic surgery

Abstract

Background: Palpation of tumors during thoracoscopic surgery remains difficult, and identification of deep-seated tumors may be impossible. This preclinical study investigated the usefulness of a novel indocyanine green (ICG) fluorescence spectroscopy system for tumor localization.Methods: ICG was diluted to 5.0×10 −2 mg/mL in fetal bovine serum (FBS) and mixed with silicone resin to prepare pseudo-tumors. Sponges of different densities and a porcine lung were placed on top of the pseudo-tumors, which were examined using a novel fluorescence spectroscopy system and a near-infrared (NIR) camera. Spectra were measured for different sponge and lung thicknesses, and the lung spectra were measured during both inflation and deflation.Results: The fluorescence spectroscopy system was able to identify tumors at depths ≥15 mm, while the NIR system was not. The spectroscopy system also detected tumors at greater depths when the density of the intervening material was lower. Depending on the density and thickness of the intervening material, the system could detect spectra as deep as 40 mm for sponges and 30 mm for lungs.Conclusions: This new fluorescence spectroscopy system can be used to identify lung tumors up to a depth of 30 mm in experiments using pseudo-tumors and a porcine lung, which may aid in tumor identification during thoracoscopic surgery.

Dose Optimization of Intravenous Indocyanine Green for Malignant Lung Tumor Localization

“…The near-infrared fluorescence spectroscopy system developed by the Advantest Corporation in Tokyo (https://www.advantest.com/) (accessed on 28 March 2024) is designed to detect the spectrum of near-infrared light [15]. It received clinical approval…”

“…We developed an innovative ICG fluorescence spectroscopy system designed for precise tumor localization [15]. This system can measure the spectrum of near-infrared light emitted by ICG in tumor tissues, offering a new dimension to surgical navigation.…”

Intraoperative molecular imaging in thoracic oncology: pushing the boundaries of precision resection for occult non-small cell lung cancer in the era of minimally invasive surgery

“…In the recent paper entitled “A novel system for analyzing indocyanine green (ICG) fluorescence spectra enables deeper lung tumor localization during thoracoscopic surgery”, Chiba and colleagues utilize a novel near-infrared (NIR) spectroscopy device that aims to detect nonpalpable and visually occult pulmonary nodules with various well thought-out preclinical and porcine models ( 1 ). They describe reliable detection of ICG-labeled tumors as deep as 30 mm from the pleural surface in inflated lungs with their technique, which is an important principle for minimally invasive intraoperative molecular imaging (IMI)-guided cancer resections ( 2 ).…”

“…Chiba and associates, in this study, attempt to address this significant challenge by implementing a novel ICG fluorescence calibrated spectroscopy device that has tissue penetration deeper than NIR light-source enabled IMI devices. Using calculated and astute preclinical investigative methods, the authors describe ICG fluorescence detection well beyond the current capabilities of ex vivo systems ( 1 ). This finding has the potential to expand the patient population that can benefit from IMI assistance during minimally invasive resections.…”

Use of indocyanine green (ICG) fluorescence spectroscopy in thoracoscopic surgery: seeing beyond the unseen

“…In their recent paper, “A novel system for analyzing indocyanine green (ICG) fluorescence spectra enables deeper lung tumor localization during thoracoscopic surgery”, Chiba et al ( 15 ) report the successful localisation of deep pulmonary lesions using ICG fluorescence and a new spectroscopy system. We congratulate the authors on their well-designed work and for overcoming the current challenges in intraoperative localisation using conventional NIR cameras.…”