title: Decision Based on Narrow Band Imaging Cystoscopy without a Referential Normal Standard Rather Increases Unnecessary Biopsy in Detection of Recurrent Bladder Urothelial Carcinoma Early after Intravesical Instillation.
abstract: OBJECTIVE
  The purpose of this study was to calculate the operating characteristics of narrowband imaging (NBI) cystoscopy versus traditional white light cystoscopy (WLC) in common clinical scenarios involving suspicion of bladder urothelial carcinoma (UC).
  
  
  METHODS
  Sixty-three consecutive patients initially underwent WLC and then NBI in a single session for evaluation of microscopic hematuria (group I, n=20), gross hematuria (group II, n=19), and follow-up for prior UC (group III, n=24), by an experienced urologist. All lesions that were abnormal in contrast with adjacent normal mucosa were diagnosed as positive and biopsied.
  
  
  RESULTS
  Sixty-six biopsies from 47 patients were performed. Pathologic examination showed 17 cases of UC from 21 sites. While the overall sensitivity of NBI was similar to that of WLC (100% vs. 94.1%), the specificity of NBI was significantly lower than that of WLC (50% vs. 86.9%, p < 0.001), particularly in group III (38.9% vs. 88.9%, p=0.004). Based on identification by NBI only, 23 additional biopsies from 18 cases were performed for identification of one patient with UC, who belonged to group III. In this group, to identify this specific patient, 15 additional biopsies were performed from 10 patients. All seven cases with positive findings from NBI within 2 months after the last intravesical therapy were histologically proven as negative.
  
  
  CONCLUSIONS
  In evaluation for recurrence early after intravesical instillation, the decision based on NBI increased unnecessary biopsy in the absence of an established standard for judging NBI.
authors.affiliation: Department of Urology, Yeungnam University College of Medicine, Daegu, Korea.
authors.forename: Phil Hyun
authors.initials: PH
authors.lastname: Song
authors.affiliation: Department of Urology, Korea University School of Medicine, Seoul, Korea.
authors.forename: Seok
authors.initials: S
authors.lastname: Cho
authors.affiliation: Department of Urology, Yeungnam University College of Medicine, Daegu, Korea.
authors.forename: Young Hwii
authors.initials: YH
authors.lastname: Ko
mesh_terms: D000283:Administration, Intravesical; D000368:Aged; D001706:Biopsy / Q000706:statistics & numerical data*; D003558:Cystoscopy / Q000592:standards; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D062048:Narrow Band Imaging / Q000592:standards; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis*; D012015:Reference Standards; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis*
keywords: Cystoscopy; Narrow band imaging; Urinary bladder neoplasms