Evaluation of visualization of squamous cell carcinoma of esophagus and pharynx using an autofluorescence imaging videoendoscope system

Abstract

Background and Aim: An autofluorescence imaging (AFI) videoendoscope system produces pseudo-color images combining autofluorescence and green reflectance, with the utility of this system previously confirmed for the diagnosis of bronchial squamous cell carcinoma (SCC). Our aim was to evaluate visualization of esophageal and pharyngeal SCC comparing AFI with white light endoscopy (WLE). Methods: Thirty-two patients with superficial esophageal SCC and 11 patients with superficial pharyngeal SCC diagnosed in other hospitals were enrolled in this prospective study. We observed the esophagus and pharynx with WLE followed by AFI and took both WLE and AFI images of the esophageal and pharyngeal SCC. Three experienced endoscopists subsequently evaluated the visualization quality of images from both systems on a threetier scale: visible, illegible and invisible. Results: A total of 39 superficial esophageal SCC were diagnosed with 20, 11 and eight lesions classified as visible, illegible and invisible, respectively, by WLE compared to 31, three and five lesions, respectively, using AFI. Using AFI, 79% of superficial esophageal SCC lesions were visible, compared to only 51% with WLE (P < 0.05). In addition, 12 superficial pharyngeal SCC were diagnosed with four, five and three lesions considered as visible, illegible and invisible, respectively, using WLE in contrast to nine, three and 0 lesions, respectively, by AFI. Thus, using AFI, 75% of superficial pharyngeal SCC lesions were visible compared with only 33% with WLE (P = 0.13). Conclusion:The AFI system appears to be more useful than WLE for early diagnosis of SCC of the esophagus and pharynx.

Comparison of Narrowband Imaging with Autofluorescence Imaging for Endoscopic Visualization of Superficial Squamous Cell Carcinoma Lesions of the Esophagus

“…The AFI videoendoscope system can distinguish neoplastic from nonneoplastic tissue [22–27], and there have been recent reports indicating the AFI system had an advantage over standard WLE in the detection of early esophageal cancers with AFI image quality being acceptable for the purpose of such detection [25, 26]. The NBI system is another novel, noninvasive optical-digital imaging method that has shown promising results in the detection of esophageal and pharyngeal SCC [15–22].…”

“…In addition, magnification endoscopy conducted with NBI can reveal morphological changes in the capillary vessels of such SCCs so as to distinguish between neoplastic lesions and inflammatory conditions and be useful in predicting histological depth of invasion [15–19]. Both the NBI [15–22] and AFI [22–26] systems could play an important role in the future detection of such cancer because each system has been shown to improve the endoscopic visualization of esophageal SCCs without any of the disadvantages associated with LC.…”

Autofluorescence imaging

“…8,9 In a pilot study of 32 patients referred for the management of superficial esophageal squamous cell carcinoma, the proportion of clearly visible lesions was significantly higher with AFI than with WLI (79% vs 51%, P Ͻ .05). 9…”

Current Status of Optical Imaging for Evaluating Lymph Nodes and Lymphatic System

“…Autofluorescence imaging uses these differences in fluorescent emission intensities between lesions and normal tissue to facilitate lesion detection. Currently, autofluorescence imaging is most commonly used for ocular and gastrointestinal imaging, and is useful for detecting early esophageal squamous cell carcinoma ( 4 , 5 ). Autofluorescence imaging can be safely applied, since exogenous fluorescent contrast is not administered into the body, which can be potentially toxic.…”