Assessment of novel endoscopic techniques for visualizing superficial esophageal squamous cell carcinoma: autofluorescence and narrow-band imaging.

Lugol chromoendoscopy (LCE) is a useful technique for visualizing superficial esophageal squamous cell carcinoma (SESCC), but the stimulating effect of the Lugol solution can sometimes cause clinical problems. Newly developed techniques such as narrow-band imaging (NBI) and autofluorescence imaging (AFI) enable SESCC to be easily visualized without LCE. This study aimed to assess the visualizing power of white-light imaging (WLI), NBI, and AFI, compared with LCE. Sixteen patients with 16 SESCCs underwent LCE and endoscopy with NBI and AFI before endoscopic or surgical treatment. Twenty sets of endoscopic SESCC images were prepared, each of which contained still images from WLI, NBI, AFI, and LCE. The image sets were shown to 25 endoscopists, who then each completed a questionnaire about the ease-of-detection of the SESCCs, scoring WLI, NBI, and AFI images with reference to a perfect score for LCE; mean scores were compared. Overall, significantly higher scores were given for NBI than for WLI and AFI, with no significant difference between WLI and AFI. Stratification by endoscopist characteristics indicated that younger or less experienced endoscopists gave significantly higher scores for AFI than WLI. Stratification by lesion characteristics revealed that AFI had significantly higher scores than WLI for flat/elevated lesions or those with diameter >or=20 mm; scores were significantly lower for depressed lesions or those with diameter <20 mm. For SESCC, the visualizing power of NBI seems more similar to that of LCE than AFI or WLI: NBI might be more useful than AFI or WLI in detecting SESCC. AFI seems to have both superior and inferior visualizing power to WLI depending on characteristics of endoscopists or SESCC lesions.