High definition bronchoscopy: a randomized exploratory study of diagnostic value compared to standard white light bronchoscopy and autofluorescence bronchoscopy

Abstract

Background: Videobronchoscopy is an essential diagnostic procedure for evaluation of the central airways and pivotal for the diagnosis and staging of lung cancer. Technological improvements have resulted in high definition (HD) images with advanced real time image enhancement techniques (i-scan).

Objectives: In this study we aimed to explore the sensitivity of HD+ i-scan bronchoscopy for detection of epithelial changes like vascular abnormalities and suspicious preinvasive lesions, and tumors.

Methods: In patients scheduled for a therapeutic or diagnostic procedure under general anesthesia videos of the bronchial tree were made using 5 videobronchoscopy modes in random order: normal white light videobronchoscopy (WLB), HD-bronchoscopy (HD), HD bronchoscopy with surface enhancement technique (i-scan1), HD with surface- and tone enhancement technique (i-scan2) and dual mode autofluorescence videobronchoscopy (AFB). The videos were scored in random order by two independent and blinded expert bronchoscopists.

Results: In 29 patients all videos were available for analysis. Vascular abnormalities were scored most frequently in HD + i-scan2 bronchoscopy (1.33 ± 0.29 abnormal or suspicious sites per patient) as compared to 0.12 ± 0.05 site for AFB (P = 0.003). Sites suspicious for preinvasive lesions were most frequently reported using AFB (0.74 ± 0.12 sites per patient) as compared to 0.17 ± 0.06 for both WLB and HD bronchoscopy (P = 0.003). Tumors were detected equally by all modalities. The preferred modality was HD bronchoscopy with i-scan (tone- plus surface and surface enhancement in respectively 38% and 35% of cases P = 0.006).

Conclusions: This study shows that high definition bronchoscopy with image enhancement technique may result in better detection of subtle vascular abnormalities in the airways. Since these abnormalities may be related to preneoplastic lesions and tumors this is of clinical relevance. Further investigations using this technique relating imaging to histology are warranted.

Figure 1

Consort flow chart of patients included the study. HNC: head and neck cancer referral patients.

Figure 2

Representative bronchoscopy images from two patients using (from top to bottom) normal white light videobronchoscopy (WLB, panels a and f); HD-bronchoscopy (panels b and g); HD+ i-scan 1: HD bronchoscopy with surface enhancement (panels c and h); HD+ i-scan2: HD bronchoscopy with surface- and tone enhancement (panels d and i) and autofluorescence bronchoscopy (AFB) in twin mode with WLB image on the left and AFB on the right (panels e and j). The bronchoscopic images on the left are from a patient with a (recurrent) squamous cell non small cell lung carcinoma in the mid trachea on the left lateral wall. The images on the on the right show a abnormal vascular pattern. Pathology from this site showed squamous metaplasia, some fibrosis and signs of active inflammation.

Figure 3

Number of sites with abnormal and suspicious vascular changes. WLB: standard white light bronchoscopy; HD: High Definition bronchoscopy; i-scan1: HD bronchoscopy with surface enhancement; i-scan2: HD bronchoscopy with tone enhancement; AFB: autofluorescence video bronchoscopy twin mode (dual image SAFE3000).

Figure 4

Number of sites with suspicious preinvasive lesions. WLB: standard white light bronchoscopy; HD: High Definition bronchoscopy; i-scan1: HD bronchoscopy with surface enhancement; i-scan2: HD bronchoscopy with tone enhancement; AFB: autofluorescence video bronchoscopy dual image mode (SAFE3000).

Figure 5

Preferred modality determined in joined reading expressed as percentage of total. WLB: standard white light bronchoscopy; HD: High Definition bronchoscopy; i-scan1: HD bronchoscopy with surface enhancement; i-scan2: HD bronchoscopy with tone enhancement; AFB: autofluorescence video bronchoscopy dual image mode (SAFE3000).