title: Highest power magnification with narrow-band imaging is useful for improving diagnostic performance for endoscopic delineation of early gastric cancers.
abstract: OBJECTIVE
  Magnifying endoscopy with narrow-band imaging (ME-NBI) is more reliable than chromoendoscopy (CE) for delineating the horizontal extent of early gastric cancers prior to endoscopic submucosal dissection (ESD). However, the added benefits of ME-NBI over CE in terms of the difference in magnification level have yet to be elucidated. The aim of this study was to investigate the improvement in diagnostic accuracy for tumor delineation obtained with different magnification levels of ME-NBI following CE.
  
  
  METHODS
  This was a retrospective study, performed at a single tertiary referral center. A series of 158 consecutive patients with 161 early gastric cancers resected en bloc using ESD was included in the study. The margins of each lesion were examined in their entirety using CE, followed by low power optical magnifying endoscopy with narrow-band imaging (LM-NBI), and finally the highest power optical magnifying endoscopy with narrow-band imaging (HM-NBI). The primary endpoint was the added benefit, as measured using the successful delineation rate, for the delineation of gastric cancer margins using CE + LM-NBI vs CE, and for CE + LM-NBI + HM-NBI vs CE + LM-NBI.
  
  
  RESULTS
  The successful delineation rates (95 % CI) using CE, CE + LM-NBI and CE + LM-NBI + HM-NBI were 72.7 % (68.5-79.9 %), 88.9 % (84.2-93.8 %), and 98.1 % (95.8-100 %). The diagnostic accuracy improved significantly for CE + LM-NBI compared with CE (P < 0.001), and for HM-NBI compared with LM-NBI (P < 0.001).
  
  
  CONCLUSIONS
  HM-NBI is useful for improving diagnostic performance for endoscopic delineation of early gastric cancers, following CE and LM-NBI.
authors.affiliation: Department of Gastroenterology, Kochi Red Cross Hospital Japan, 2-13-51 Sinhonmachi, Kochi-city, Kochi, 780-8562, Japan. ucchy31@yahoo.co.jp.
authors.forename: Kunihisa
authors.initials: K
authors.lastname: Uchita
authors.affiliation: Department of Endoscopy, Fukuoka University Chikushi Hospital Japan, 1-1-1 Zokumyoin, Chikushino-city, Fukuoka, 818-8502, Japan. yao@fukuoka-u.ac.jp.
authors.forename: Kenshi
authors.initials: K
authors.lastname: Yao
authors.affiliation: Department of Gastrointestinal Oncology, Osaka Medical Center for Cancer and Cardiovascular Diseases Japan, 3-3, Nakamichi 1-chome, Higashinari-ku, 537-8511, Osaka, Japan. noriya.uedo@gmail.com.
authors.forename: Noriya
authors.initials: N
authors.lastname: Uedo
authors.affiliation: Graduate School of Medicine and Engineering, University of Yamanashi, 4-3-11 Takeda, Kofu City, 400-8511, Yamanashi, Japan. shimokawa@yamanashi.ac.jp.
authors.forename: Toshio
authors.initials: T
authors.lastname: Shimokawa
authors.affiliation: Department of Gastroenterology, Kochi Red Cross Hospital Japan, 2-13-51 Sinhonmachi, Kochi-city, Kochi, 780-8562, Japan. space-rendez-vous@sings.jp.
authors.forename: Takehiro
authors.initials: T
authors.lastname: Iwasaki
authors.affiliation: Department of Gastroenterology, Kochi Red Cross Hospital Japan, 2-13-51 Sinhonmachi, Kochi-city, Kochi, 780-8562, Japan. kozikozima22@gmail.com.
authors.forename: Koji
authors.initials: K
authors.lastname: Kojima
authors.affiliation: Department of Gastroenterology, Kochi Red Cross Hospital Japan, 2-13-51 Sinhonmachi, Kochi-city, Kochi, 780-8562, Japan. ai0happiness@yahoo.co.jp.
authors.forename: Ai
authors.initials: A
authors.lastname: Kawada
authors.affiliation: Department of Gastroenterology, Kochi Red Cross Hospital Japan, 2-13-51 Sinhonmachi, Kochi-city, Kochi, 780-8562, Japan. aoi.blue.tomato125@gmail.com.
authors.forename: Mizu
authors.initials: M
authors.lastname: Nakayama
authors.affiliation: Department of Gastroenterology, Kochi Red Cross Hospital Japan, 2-13-51 Sinhonmachi, Kochi-city, Kochi, 780-8562, Japan. oka_krc@yahoo.co.jp.
authors.forename: Michiyo
authors.initials: M
authors.lastname: Okazaki
authors.affiliation: Department of Gastroenterology, Kochi Red Cross Hospital Japan, 2-13-51 Sinhonmachi, Kochi-city, Kochi, 780-8562, Japan. iwamura@crocus.ocn.ne.jp.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Iwamura
mesh_terms: D000368:Aged; D055088:Early Detection of Cancer / Q000379:methods*; D005260:Female; D005773:Gastroscopy / Q000379:methods*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008297:Male; D062048:Narrow Band Imaging / Q000379:methods*; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000175:diagnosis*