title: Evaluation of gastric cancer diagnosis using new ultrathin transnasal endoscopy with narrow-band imaging: preliminary study.
abstract: OBJECTIVE
  The new developed ultrathin transnasal endoscope, the GIF-XP290N, makes possible a resolving power similar to the GIF-H260 at a distance of 3 mm. In this study, using the GIF-XP290N, we evaluated whether endoscopic diagnosis (discrimination between benign and malignant) of gastric lesions is possible using nonmagnified narrow-band imaging (NBI) endoscopy.
  
  
  METHODS
  The subjects were 255 consecutive patients who underwent screening of the gastrointestinal tract using new ultrathin transnasal endoscopy. Their average age was 65.2 ± 11.4 years. The male-female ratio was 2.5:1. All cases were examined using conventional white-light imaging (WLI) and nonmagnified NBI. When a depressed lesion was detected in the stomach, it was examined using WLI, then NBI close examination (at about 3 mm). We observed the mucosal structure of the lesion using close visualization with NBI. Concerning mucosal structural changes, we looked for a clear demarcation line between the lesion and the surrounding mucosa, and loss, irregularity, or nonuniformity of the lesion mucosal microsurface pattern.
  
  
  RESULTS
  A total of 52 depressed lesions were examined. The histological diagnosis was cancer for 8 lesions, and noncancer for 44 lesions. WLI examination yielded a sensitivity of 50.0% (4/8), specificity of 63.6% (28/44), and accuracy 61.5% (32/52). On the other hand, NBI close examination yielded a sensitivity of 87.5% (7/8), specificity of 93.2% (41/44), and accuracy of 92.3% (48/52), significantly higher.
  
  
  CONCLUSIONS
  NBI close examination using ultrathin transnasal endoscopy enables mucosal diagnosis even without magnification and was considered to be an effective technique for improving endoscopic diagnosis.
authors.affiliation: Endoscopy Centre, Tokyo Medical University Hospital, Tokyo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kawai
authors.forename: Kyosuke
authors.initials: K
authors.lastname: Yanagizawa
authors.forename: Sakiko
authors.initials: S
authors.lastname: Naito
authors.forename: Hiroko
authors.initials: H
authors.lastname: Sugimoto
authors.forename: Masakatsu
authors.initials: M
authors.lastname: Fukuzawa
authors.forename: Takuji
authors.initials: T
authors.lastname: Gotoda
authors.forename: Jun
authors.initials: J
authors.lastname: Matsubayashi
authors.forename: Toshitaka
authors.initials: T
authors.lastname: Nagao
authors.forename: Sumito
authors.initials: S
authors.lastname: Hoshino
authors.forename: Akihiko
authors.initials: A
authors.lastname: Tsuchida
authors.forename: Fuminori
authors.initials: F
authors.lastname: Moriyasu
mesh_terms: D000368:Aged; D005260:Female; D005773:Gastroscopy / Q000379:methods*; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D012680:Sensitivity and Specificity; D013274:Stomach Neoplasms / Q000175:diagnosis* / Q000473:pathology
keywords: Narrow band imaging; close examination; gastric cancer; mucosal structure; transnasal endoscopy