Narrow Band Imaging with High-resolution Bronchovideoscopy: a New Approach for Visualizing Angiogenesis in Squamous Cell Carcinoma of the Lung

Objectives: We investigated the ability of a high-resolution bronchovideoscopy system with narrow band imaging (NBI) to detect blood vessel structures in squamous cell carcinoma (SCC) of bronchi, as well as squamous dysplasia.

Methods: Seventy-nine patients with either abnormal sputum cytology or lung cancer were entered into the study. First, high-resolution bronchovideoscopy with white light was performed. Observations were repeated using NBI light to examine microvascular structures in the bronchial mucosa. Spectral features of the RGB (red/green/blue) sequential videoscope system were changed from a conventional RGB filter to the new NBI filter. The wavelength ranges of the NBI filter were: 400-430 nm (blue), 400-430 nm (green) and 520-560 nm (red).

Results: The following were clearly observed with NBI with high-resolution bronchovideoscopy: increased vessel growth and complex networks of tortuous vessels of various sizes, in squamous dysplasia; some dotted vessels, in addition to increased vessel growth and complex networks of tortuous vessels, in ASD; several dotted vessels and spiral or screw type tumor vessels of various sizes and grades, in SCC. Capillary blood vessel and/or tumor vessel mean diameters of ASD, CIS, microinvasive and invasive carcinoma were 41.4+/-9.8 microm, 63.7+/-8.2 microm, 136.5+/-29.9 microm and 259.4+/-29.6 microm, respectively. These results indicated a statistically significant increase of mean vessel diameters in the four groups (P<0.0001).

Conclusion: NBI with high-resolution bronchovideoscopy was useful for detecting the increased vessel growth and complex networks of tortuous vessels, dotted vessels and spiral or screw type tumor vessels of bronchial mucosa. This may enable detecting the onset of angiogenesis during multi-step carcinogenesis of the lung.