Novel locally nebulized indocyanine green for simultaneous identification of tumor margin and intersegmental plane

Segmentectomy, recommended for early-stage lung cancer or compromised lung function, demands precise tumor detection and intersegmental plane identification. While indocyanine green (ICG) commonly aids in these aspects using near-infrared imaging, its separate administrations through different routes and times can lead to complications and patient anxiety. This study aims to develop a lung-specific delivery method by nebulizing low-dose ICG to targeted lung segments, allowing simultaneous detection of lung tumors and intersegmental planes across diverse animal models.

To optimizing the dose of ICG for lung tumor and interlobar fissure detection, different doses of ICG (0.25, 0.1, and 0.05 mg/kg) were nebulized to rabbit lung tumor models. The distribution of locally nebulized ICG in targeted segments was studied to evaluate the feasibility of detecting lung tumor and intersegmental planes in canine lung pseudotumor models.

Near-infrared fluorescence imaging demonstrated clear visualization of lung tumor margin and interlobar fissure using local nebulization of 0.1 mg/kg ICG for only 4 min during surgery in the rabbit models. In the canine model, the local nebulization of 0.05 mg/kg of ICG into the target segment enabled clear visualization of pseudotumor and intersegmental planes for 30 min.

This innovative approach achieves a reduction in ICG dose and prolonged the visualization time of the intersegmental plane and effectively eliminates the need for the hurried marking of tumors and intersegmental planes. The authors anticipate that lung-specific delivery of ICG will prove valuable for image-guided limited resection of lung tumors in clinical practice.