title: Detection of bladder urothelial carcinoma using in vivo noncontact, ultraviolet excited autofluorescence measurements converted into simple color coded images: a feasibility study.
abstract: OBJECTIVE
  A difficulty in nonmuscle invasive bladder cancers is the diagnosis of flat and small lesions during white light cystoscopy. We assessed a prototype that measures ultraviolet laser induced autofluorescence for endoscopic detection of nonmuscle invasive bladder cancer.
  
  
  METHODS
  We compared spectroscopic results with histological findings in 3 groups, including normal urothelium, papillary tumors and flat lesions. The developed method is based on exciting the fluorescence of molecules naturally present in tissue using ultraviolet laser pulses. The diagnostic signal was converted into the intensity ratio of the emitted light at approximately 360 and 450 nm. This ratio depends on the histopathological state of the tissue. The signal was converted into a simple color coded image, in which green indicates normal tissue and red indicates neoplasm.
  
  
  RESULTS
  A total of 14 patients were included in analysis. At 360 and 450 nm excitation wavelengths the overall fluorescence intensity of bladder tumors was clearly decreased compared to that of normal urothelium regardless of tumor stage or grade. At the 308 nm excitation wavelength the shape of the tumor spectra, including carcinoma in situ, was markedly different from that of normal or nonspecific inflammatory mucosa. The correlation between red images and tumor in the specimen was 100%. No absolute intensity determinations were required since a definite diagnosis was established based on the fluorescence intensity ratio at 360 and 450 nm.
  
  
  CONCLUSIONS
  This feasibility study confirms the functionality of our clinical prototype for the noncontact imaging detection of nonmuscle invasive bladder cancer via an endoscope using ultraviolet excited autofluorescence measurements.
authors: Université Paris 13, Laboratoire de Physique des Lasers, Institut Galilée, Villetaneuse, France.
authors: Christof
authors: C
authors: Schäfauer
authors: Dominique
authors: D
authors: Ettori
authors: Morgan
authors: M
authors: Rouprêt
authors: Véronique
authors: V
authors: Phé
authors: Jean-Michel
authors: JM
authors: Tualle
authors: Eric
authors: E
authors: Tinet
authors: Sigrid
authors: S
authors: Avrillier
authors: Christophe
authors: C
authors: Egrot
authors: Olivier
authors: O
authors: Traxer
authors: Olivier
authors: O
authors: Cussenot
mesh_terms: D000328:Adult; D000368:Aged; D002295:Carcinoma, Transitional Cell / Q000175:diagnosis* / Q000473:pathology; D016022:Case-Control Studies; D059019:Clinical Coding; D003116:Color; D003558:Cystoscopy / Q000295:instrumentation / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007834:Lasers; D008297:Male; D008875:Middle Aged; D061848:Optical Imaging / Q000295:instrumentation / Q000379:methods*; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods; D014466:Ultraviolet Rays; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis* / Q000473:pathology; D019459:Urothelium / Q000473:pathology