title: Confocal laser endomicroscopy of bladder tumors associated with photodynamic diagnosis: an ex vivo pilot study.
abstract: OBJECTIVE
  To improve the sensitivity of white light cystoscopy, photodynamic diagnosis (PDD) is useful but has low specificity. Recently, confocal laser endomicroscopy (CLE) has been used for the diagnosis of urothelial cell carcinoma. The main objective was to examine the feasibility of simultaneous PDD and CLE. A secondary objective was to determine whether hexyl aminolevulinic acid (HAL) can be used just as fluorescein for CLE.
  
  
  METHODS
  In the present prospective single-center study with a same-patient comparison, patients with suspected urothelial cell carcinoma underwent surgical exploration after receiving a bladder instillation of HAL. After resection of suspected lesions under blue light, the samples were inspected ex vivo using CLE with and without fluorescein. Simultaneous blue light CLE inspection was performed. All samples were then transferred to the pathology laboratory for the classic analysis.
  
  
  RESULTS
  Of the 12 patients studied, blue light cystoscopy revealed suspect lesions in 11; 10 had pathology proven urothelial cell carcinoma. CLE analysis was not modified by sample exposure to blue light, which facilitated orientation of the fiber toward the suspect red fluorescence areas. The fluorescence obtained with HAL-CLE was insufficient for microscopic histologic analysis, unlike the resolution obtained with fluorescein. Comparing CLE and the pathologic findings was possible and conclusive for 4 of 12 samples.
  
  
  CONCLUSIONS
  Combining PDD and CLE ex vivo demonstrated the usefulness of HAL for guiding blue light CLE. HAL was insufficient to allow histologic CLE, which required the use of fluorescein. The results of this pilot study have indicated the feasibility of CLE. However, an in vivo method incorporating fluorescein and PDD will be required to improve the diagnostic specificity of PDD alone.
authors.affiliation: Université Lille Nord de France, Lille, France.
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Bonnal
authors.forename: Aurélien
authors.initials: A
authors.lastname: Rock
authors.forename: Antoine
authors.initials: A
authors.lastname: Gagnat
authors.forename: Stephanos
authors.initials: S
authors.lastname: Papadopoulos
authors.forename: Bernard
authors.initials: B
authors.lastname: Filoche
authors.forename: Brigitte
authors.initials: B
authors.lastname: Mauroy
mesh_terms: D000283:Administration, Intravesical; D002295:Carcinoma, Transitional Cell / Q000175:diagnosis*; D003558:Cystoscopy; D003937:Diagnosis, Differential; D005240:Feasibility Studies; D019793:Fluorescein / Q000008:administration & dosage; D005456:Fluorescent Dyes / Q000008:administration & dosage; D006801:Humans; D018613:Microscopy, Confocal / Q000379:methods*; D017319:Photosensitizing Agents / Q000008:administration & dosage; D010865:Pilot Projects; D011446:Prospective Studies; D015203:Reproducibility of Results; D001749:Urinary Bladder Neoplasms / Q000175:diagnosis*; D019459:Urothelium / Q000473:pathology*
chemical_list: D005456:Fluorescent Dyes; D017319:Photosensitizing Agents; D019793:Fluorescein