Usefulness of NBI to Distinguish Between Non-Neoplastic and Neoplastic Lesions Without the Influence of Performer Whether He Is Expert Or Not

Abstract

Background and Aim: We reported that the presence of meshed brown capillary vessels on magnifying endoscopy using narrow-band imaging (NBI) is useful to distinguish between non-neoplastic and neoplastic lesions without the application of any dye solution. We believe that the using NBI as optical chromoendoscopy save the time and cost on screening colonoscopy. But it is not defined whether the accuracy of diagnosis is influenced by the experience of endoscopists. The study aimed to evaluate the efficacy of accuracy using NBI without the influence from performer. Methods: From 2005 October to 2006 October, 50 lesions of less than 10 mm in size (hyperplastic polyp 25 lesions and adenoma 25 lesions), observed sufficiently with conventional colonoscopy, NBI, chromoendoscopy and magnifying chromoendoscopy. All lesions were diagnosed separately under each method in order to avoid the influence from other methods. This study is participated with total of 13 endoscopists in National Cancer Center East, including 5 experts (Group A), 2 experts in upper endoscopy (Group B), 6 beginners (Group C). The Group C was given basic education before diagnosing lesions. We compared the accuracy of endoscopic diagnosis among these endoscopists groups under each observation method respectively. Results: We excluded the lesions which accuracy were less than 50% in all four methods of observation from this study because we concluded the pictures of lesion were poor. So, we studied 47 lesions (hyperplastic polyp 22 lesions and adenoma 25 lesions). Total accuracy of conventional colonoscopy, NBI, chromoendoscopy and magnifying chromoendoscopy were 69.4%, 81.5%, 65.3%, 73.1% respectively. The most agreeable accuracy was diagnosis by NBI, there was significant difference in accuracy between conventional colonoscopy and NBI (P < 0.001). In Group A, accuracy of each methods were: 77.6%, 88.1%, 70.6% and 80.4%. Group B: 70.2%, 76.6% and 62.3%, 64.9%. Group C: 63.5%, 77.7%, 61.7%, 69.5%. In each Group, the accuracy of diagnosis by NBI was most favorable. In Group C, there was significant difference in accuracy between conventional colonoscopy and NBI (P < 0.05). In Group A and B, there was not statistically significant. Compared the accuracy according to four observation methods among the Group A, B and C. In conventional colonoscopy, there was significant difference between Group A and C (P < 0.05). In other observation methods, there were not statistically significant. Conclusion: By giving basic education before diagnosis, the accuracy of endoscopic diagnosis to distinguish between non-neoplastic and neoplastic by using NBI was agreeable independent of performer whether he is expert or non expert.