title: A Pilot Study of In Vivo Confocal Laser Endomicroscopy of Upper Tract Urothelial Carcinoma.
abstract: OBJECTIVE
  Tissue diagnosis of upper tract urothelial carcinoma (UTUC) is limited by variance in tumor sampling by standard ureteroscopic biopsy. Optical imaging technologies can potentially improve UTUC diagnosis, surveillance, and endoscopic treatment. We previously demonstrated in vivo optical biopsy of urothelial carcinoma of the bladder using confocal laser endomicroscopy (CLE). In this study, we evaluated a new 0.85-mm imaging probe in the upper urinary tract and demonstrated feasibility and compatibility with standard ureteroscopes to achieve in vivo optical biopsy of UTUC.
  
  
  METHODS
  Fourteen patients scheduled for ureteroscopy of suspected upper tract lesions or surveillance of UTUC were recruited. After intravenous (IV) administration of fluorescein, CLE was performed using a 0.85-mm-diameter imaging probe inserted through the working channel of standard ureteroscopes. Acquired confocal video sequences were reviewed and analyzed. A mosaicing algorithm was used to compile a series of images into a single larger composite image. Processed CLE images were compared with standard histopathologic analysis.
  
  
  RESULTS
  Optical biopsy of the UTUC using CLE was effectively achieved during standard ureteroscopy. There were no adverse events related to IV fluorescein administration or image acquisition. Confocal imaging of UTUC showed characteristic features similar to urothelial carcinoma of the bladder, including papillary structure, fibrovascular stalks, and pleomorphism. Lamina propria in normal areas of the renal pelvis and ureter was also identified.
  
  
  CONCLUSIONS
  We report an initial feasibility of CLE of UTUC. Pending further clinical investigation, CLE may become a useful adjunct to ureteroscopic biopsy, endoscopic ablation, and surveillance of UTUC.
authors.affiliation: 1 Department of Urology, Stanford University School of Medicine , Stanford, California.|2 Veterans Affairs Palo Alto Health Care System , Palo Alto, California.
authors.forename: Daniel
authors.initials: D
authors.lastname: Bui
authors.affiliation: 1 Department of Urology, Stanford University School of Medicine , Stanford, California.|2 Veterans Affairs Palo Alto Health Care System , Palo Alto, California.
authors.forename: Kathleen E
authors.initials: KE
authors.lastname: Mach
authors.affiliation: 1 Department of Urology, Stanford University School of Medicine , Stanford, California.|2 Veterans Affairs Palo Alto Health Care System , Palo Alto, California.
authors.forename: Dimitar V
authors.initials: DV
authors.lastname: Zlatev
authors.affiliation: 2 Veterans Affairs Palo Alto Health Care System , Palo Alto, California.|3 Department of Pathology, Stanford University School of Medicine , Stanford, California.
authors.forename: Robert V
authors.initials: RV
authors.lastname: Rouse
authors.affiliation: 1 Department of Urology, Stanford University School of Medicine , Stanford, California.|2 Veterans Affairs Palo Alto Health Care System , Palo Alto, California.
authors.forename: John T
authors.initials: JT
authors.lastname: Leppert
authors.affiliation: 1 Department of Urology, Stanford University School of Medicine , Stanford, California.|2 Veterans Affairs Palo Alto Health Care System , Palo Alto, California.
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Liao
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002295:Carcinoma, Transitional Cell / Q000473:pathology*; D005260:Female; D006801:Humans; D000069416:Intravital Microscopy / Q000379:methods*; D007680:Kidney Neoplasms / Q000473:pathology*; D007682:Kidney Pelvis / Q000473:pathology*; D008297:Male; D018613:Microscopy, Confocal / Q000379:methods; D008875:Middle Aged; D010865:Pilot Projects; D014513:Ureter / Q000473:pathology; D014516:Ureteral Neoplasms / Q000473:pathology*; D018666:Ureteroscopy / Q000379:methods*