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

To evaluate the technical feasibility and potential clinical applicability of a novel fluorescence-guided bronchoscopic localization strategy using a solid fluorescent silicone rubber marker for intraoperative localization of small peripheral pulmonary nodules.

An ex vivo human lung model was established using 4 freshly resected human pulmonary lobes. A radiopaque fluorescent silicone rubber marker (LuxSeed) was deployed bronchoscopically 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 noncompression and temporary compression conditions, and fluorescence intensity was quantified by signal-to-background ratio analysis.

Successful deployment was achieved in all 4 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.

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.