Fluorescence-guided bronchoscopic localization with a novel silicone marker: An ex vivo human proof-of-concept study

Objective To evaluate the technical feasibility and potential clinical applicability of a novel fluorescence-guided bronchoscopic localization technology using a solid fluorescent silicone rubber marker for intraoperative localization of small peripheral pulmonary nodules. Methods An ex vivo human lung model was established using four freshly resected human pulmonary lobes. A radiopaque fluorescent silicone rubber marker (LuxSeed) was bronchoscopically deployed into peripheral bronchi without fluoroscopic or navigation guidance. Transpleural fluorescence was evaluated using a commercially available near-infrared thoracoscopic imaging system. Fluorescence detectability was assessed according to lung parenchymal thickness under non-compression and temporary compression conditions, and fluorescence intensity was quantified by signal-to-background ratio analysis. Results Successful deployment was achieved in all four resected pulmonary lobes. Fluorescence was consistently detected through lung parenchyma up to 12 mm thick without compression. Although fluorescence was not visible at depths of 15 and 20 mm under static conditions, temporary lung compression restored fluorescence detectability. Quantitative image analysis demonstrated improved signal-to-background ratios with compression, consistent with visual assessment. The marker was readily visualized using a standard near-infrared thoracoscopic imaging platform without dedicated localization equipment. Conclusions This proof-of-concept study demonstrates the feasibility of a novel fluorescence-guided bronchoscopic localization technology using a solid fluorescent silicone rubber marker. Compatibility with existing near-infrared thoracoscopic imaging systems and improved detectability during routine lung compression support future clinical evaluation in minimally invasive thoracic surgery.