PURPOSE: Narrow-band imaging (NBI) is a novel technique which takes advantage of the increased blood supply of dysplastic tissues to more clearly contrast them to adjacent tissues using specially designed optical filters corresponding to the absorption spectrum of oxyhemoglobin. The purpose of this study was to: first characterize the appearance of normal, dysplastic and frankly malignant airway lesion appearance under NBI and second to determine if NBI, could be improve identification of abnormal airway mucosa and increase biopsy yield of dysplasia and neoplasia.
METHODS: Bronchoscopy was performed on 22 patients with known or suspected bronchial dysplasia or lung malignancy using NBI and white light mode. Biopsies of abnormal areas were then sent for examination by a blinded pathologist. Photos of each biopsy site were taken. Pathologic interpretation was then compared to the corresponding images. Statistical comparisons were carried out using Fischer’s two sided exact test. Values less than p=0.05 were considered significant. 95% confidence intervals were calculated using paired t test.
RESULTS: There was one cancer and 4 dysplastic lesions out of 22 patients detected by NBI where white light imaging was considered normal. Recognition of normal versus abnormal tissue under NBI by the bronchoscopists was learned in a short period of time. In areas where white light imaging was normal and NBI was abnormal, there were 4 dysplastic and 1 malignant lesion detected. The increased rate of detection of dysplasia by NBI was statistically significant (p=0.003). The one instance of cancer detected by NBI was not statistically significant (p=0.43).
CONCLUSION: NBI identified dysplasia or cancer that was not detected by white light inspection in 23% of subjects. The modality was easy to use and added relatively little time to the overall procedure.
CLINICAL IMPLICATIONS: The addition of NBI to white light bronchoscopy holds much promise in the detection of bronchial dysplasia and malignancy. Larger scale screening studies with high-risk populations are warranted to further evaluate the usefulness of NBI in detection of early lung cancer.
DISCLOSURE: Brad Vincent, None.