Value of Autofluorescence Imaging Videobronchoscopy in Detecting Lung Cancers and Precancerous Lesions: A Review

Abstract

SummaryBronchoscopy technology is a desirable method for detecting lung cancers arising in the central airways. Most early cancers and precancerous lesions are not visible on conventional white-light bronchoscopy (WLB). Autofluorescence bronchoscopy (AFB) is a newly developed technology that exploits the difference in autofluorescence intensity between normal and tumorous tissues to detect bronchial cancers and precancerous lesions. Several types of AFB systems have been used in clinical practice, and autofluorescence imaging videobronchoscopy (AFI) is one of these AFBs. In most of the studies on AFB other than AFI, AFB has provided a much higher sensitivity but a lower specificity than WLB. Regarding AFI, recent studies have reported controversial results on the sensitivity and specificity for detecting cancers and precancerous lesions, compared with WLB. In this paper we describe the working mechanisms and characteristics of AFBs, mainly AFI, and the diagnostic performance of AFI, compared with WLB, other AFBs, and narrow-band imaging, for detecting lung cancers and precancerous lesions. Key words: autofluorescence imaging videobronchoscopy; autofluorescence bronchoscopy; white-light bronchoscopy; narrow-band imaging; lung cancer; precancerous lesion. [Respir Care 2013;58(12):2150 -2159

Autofluorescence imaging bronchoscopy as a novel approach to the management of tracheobronchopathia osteochondroplastica: a case report

“…Although it is not clear whether squamous metaplasia is the first stage of the pathogenetic process, followed by cartilage formation and ossification, or simply secondary to the chronicity of the condition, it remains the most common histopathological finding in TO patients (1,2). AFI is a newly advanced bronchoscopy system that can detect weak autofluorescence signals from the bronchial mucosa (6). This technique can identify abnormal mucosa with the aid of different colors; pathological mucosa appears magenta while normal bronchial mucosa appears green.…”

“…Bronchoscopy is the gold standard for TO diagnosis; however, it cannot satisfactorily assess subtle mucosal changes to determine the treatment response (5). Autofluorescence imaging bronchoscopy (AFI) is a recently introduced advanced endoscopic technology that can detect subtle mucosal changes with the aid of different colors (6). Here we report the AFI findings for a case involving a 42-yearold man with typical histopathological findings of TO.…”

The role of bronchoscopy in the diagnosis of early lung cancer: a review

“…Seven more studies evaluated the effectiveness of AFI: six studies found its sensitivity significantly higher than that of WLB, whereas the remaining study recorded the same value for AFI and WLB. Regarding the specificities of AFI compared to that of WLB, no univocal data were available (19) (Figure 1).…”

The technique of endoscopic airway tumor treatment

“…Autofluorescence is intensely produced by submucosal stroma, but epithelium, mucosa, and cancerous tissue emit very little fluorescence. Several mechanisms have been hypothesized to explain the different autofluorescence o f n o r m a l a n d c a n c e r o u s t i s s u e s : f o r e x a m p l e autofluorescence can change if the epithelial layer thickens, as in the presence of cancer, or if the concentrations of certain substances in the tissue, including fluorophores and nonfluorescent chromophores, change (51). Most endogenous fluorophores are associated with the tissue matrix, such as collagen and elastin, or are involved in cellular metabolic processes.…”

“…AFB is an advanced technology that exploits the autofluorescent nature of bronchial mucosa to detect tiny and subtle superficial lesions (51). Several types of AFB systems have been designed, developed, and marketed, including the LIFE system (Xillix Technologies, Richmond, British Columbia, Canada), the D-Light system (Karl Storz, Tuttlingen, Germany), and the SAFE system (Pentax, Tokyo, Japan).…”