title: Magnifying endoscopy with narrow-band imaging is more accurate for determination of horizontal extent of early gastric cancers than chromoendoscopy.
abstract: OBJECTIVE
  Although magnifying endoscopy with narrow-band imaging (ME-NBI) is reported to be useful for delineating the horizontal extent of early gastric cancers (EGCs), there are few reports which have objectively demonstrated the superiority of ME-NBI over chromoendoscopy with indigo carmine for this purpose. We conducted an exploratory comparison of the diagnostic accuracy of both modalities for the delineation of EGCs using prospectively collected data, and clarified the clinicopathological features related to inaccurate evaluation of the horizontal extent of EGCs.
  
  
  METHODS
  EGCs were assigned to the oral narrow-band imaging (O-NBI) group or the oral chromoendoscopy (O-CE) group before endoscopic submucosal dissection (ESD). The oral border was observed according to assignment, and the anal border with the other modality. The horizontal extent of the tumor was evaluated by each modality and a marking dot was placed on the visible delineation line. After ESD, the marking dots were identified pathologically and defined as "accurate evaluation" if they were located within 1 mm of the pathological tumor border. We compared the rate of accurate evaluation of ME-NBI and chromoendoscopy, and analyzed the clinicopathological features related to inaccurate evaluation.
  
  
  RESULTS
  A total of 113 marking dots evaluated by ME-NBI and 116 evaluated by chromoendoscopy were analyzed. The rate of accurate evaluation by ME-NBI was significantly higher than that by chromoendoscopy (89.4 % vs 75.9 %, P = 0.0071). The EGCs with flat borders and large EGCs were significantly related to inaccurate evaluation using ME-NBI. There were no significant factors related to inaccurate evaluation with chromoendoscopy.
  
  
  CONCLUSIONS
  The accurate evaluation rate of the horizontal extent of EGCs by ME-NBI is significantly higher than that by chromoendoscopy.
  
  
  BACKGROUND
  UMIN000007641.
authors.affiliation: Department of Gastroenterology, The University of Tokyo, Tokyo, Japan.
authors.forename: Itsuko
authors.initials: I
authors.lastname: Asada-Hirayama
authors.affiliation: Department of Gastroenterology, The University of Tokyo, Tokyo, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Kodashima
authors.affiliation: Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Sakaguchi
authors.affiliation: Department of Gastroenterology, The University of Tokyo, Tokyo, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Ono
authors.affiliation: Department of Gastroenterology, Center for Epidemiology and Preventive Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Niimi
authors.affiliation: Department of Gastroenterology, Tokatsu-Tsujinaka Hospital, Chiba, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Mochizuki
authors.affiliation: Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Tsuji
authors.affiliation: Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Chihiro
authors.initials: C
authors.lastname: Minatsuki
authors.affiliation: Department of Gastroenterology, The University of Tokyo, Tokyo, Japan.
authors.forename: Satoki
authors.initials: S
authors.lastname: Shichijo
authors.affiliation: Department of Pathology, Chiba University Hospital, Chiba, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Matsuzaka
authors.affiliation: Department of Pathology, The University of Tokyo, Tokyo, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Ushiku
authors.affiliation: Department of Pathology, The University of Tokyo, Tokyo, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Fukayama
authors.affiliation: Department of Gastroenterology, The University of Tokyo, Tokyo, Japan.
authors.forename: Nobutake
authors.initials: N
authors.lastname: Yamamichi
authors.affiliation: Department of Gastroenterology, The University of Tokyo, Tokyo, Japan; Department of Endoscopy & Endoscopic Surgery, The University of Tokyo, Tokyo, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Fujishiro
authors.affiliation: Department of Gastroenterology, The University of Tokyo, Tokyo, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Koike