Comparison of the diagnostic performance between magnifying chromoendoscopy and magnifying narrow-band imaging for superficial colorectal neoplasms: an online survey

Background and Aims Magnifying narrow-band imaging (mag-NBI) and magnifying chromoendoscopy using crystal violet staining for pit pattern analysis (pit pattern) is highly accurate for diagnosing invasion depth of superficial colorectal neoplasms. However, NBI and pit pattern have not been compared. Methods We conducted an online survey of endoscopists interested in image-enhanced endoscopy. Still images using white light, mag-NBI, and pit pattern were collected from lesions diagnosed at the National Cancer Center Hospital (NCCH), Tokyo, Japan. Sixty endoscopists from outside NCCH who typically use magnifying endoscopy were recruited for this survey. We assessed the diagnostic accuracy using receiver operating characteristic (ROC) analysis based on a calculation of the area under the ROC curve. Results One hundred early colorectal neoplasms were selected for this survey. Histopathology revealed that, although 67 of the lesions had high-grade dysplasia or carcinoma with superficial submucosal (SM-s) invasion, the other 33 lesions had a carcinoma with deep submucosal invasion (SM-d). Comparing the area under the ROC curve from mag-NBI with that of pit pattern, the latter showed significantly higher diagnostic accuracy for depth invasion (0.83 [95% CI, 0.81-0.85] for mag-NBI, 0.88 [95% CI, 0.85-0.89] for pit pattern, P  = .013). Conclusions Pit pattern should be the first choice for diagnosing invasion depth as the most reliable modality rather than mag-NBI.