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 three-tier 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.