title: Optical diagnostics for upper urinary tract urothelial cancer: technology, thresholds, and clinical applications.
abstract: OBJECTIVE
  Developments in optical diagnostics have potential for less invasive diagnosis of upper urinary tract urothelial carcinoma (UUT-UC). This systematic review provides an overview of technology, applications, and limitations of recently developed optical diagnostics in the upper urinary tract and outlines their potential for future clinical applications. In addition, current evidence was evaluated.
  
  
  METHODS
  A PubMed literature search was performed and articles on narrow band imaging (NBI), photodynamic diagnosis (PDD), Storz professional imaging enhancement system (SPIES), optical coherence tomography (OCT), and confocal laser endomicroscopy (CLE) regarding UUT-UC were reviewed for data extraction. Study quality was reviewed according to Quality Assessment of Diagnostic Accuracy Studies and Innovation, Development, Exploration, Assessment, and Long-term follow-up (IDEAL) standards.
  
  
  RESULTS
  Four articles available for quality assessment, demonstrated high level of evidence, but low level of IDEAL stage. NBI and SPIES enhance contrast of mucosal surface and vascular structures, improving tumor detection rate. A first in vivo study showed promising results. PDD uses fluorescence to improve tumor detection rate. However, due to the acute angle of the ureterorenoscopes there is an increased risk of false positives. OCT produces cross-sectional high-resolution images, providing information on tumor grade and stage. A pilot study showed promising diagnostic accuracy. CLE allows ultrahigh-resolution microscopy of tissue resulting in images of the cellular structure. CLE cannot be applied in vivo in the upper urinary tract yet, due to technical limitations.
  
  
  CONCLUSIONS
  NBI, SPIES, and PDD aim at improving visualization of UUT-UC through contrast enhancement. OCT and CLE aim at providing real-time predictions of histopathological diagnosis. For all techniques, more research has to be conducted before these techniques can be implemented in the routine management of UUT-UC. All techniques might be of value in specific clinical scenarios and allow for integration, for example, OCT with NBI, and could therefore improve tumor detection and staging and help in selecting the optimal treatment for the individual patient.
authors.affiliation: 1 Department of Urology, Academic Medical Center , Amsterdam, The Netherlands .
authors.forename: Mieke T J
authors.initials: MT
authors.lastname: Bus
authors.forename: D Martijn
authors.initials: DM
authors.lastname: de Bruin
authors.forename: Dirk J
authors.initials: DJ
authors.lastname: Faber
authors.forename: Guido M
authors.initials: GM
authors.lastname: Kamphuis
authors.forename: Patricia J
authors.initials: PJ
authors.lastname: Zondervan
authors.forename: M Pilar
authors.initials: MP
authors.lastname: Laguna Pes
authors.forename: Theo M
authors.initials: TM
authors.lastname: de Reijke
authors.forename: Olivier
authors.initials: O
authors.lastname: Traxer
authors.forename: Ton G
authors.initials: TG
authors.lastname: van Leeuwen
authors.forename: Jean J M C H
authors.initials: JJ
authors.lastname: de la Rosette
mesh_terms: D002295:Carcinoma, Transitional Cell / Q000175:diagnosis*; D006801:Humans; D018613:Microscopy, Confocal; D062048:Narrow Band Imaging / Q000379:methods; D041623:Tomography, Optical Coherence / Q000379:methods; D018666:Ureteroscopy; D014551:Urinary Tract / Q000473:pathology*; D014571:Urologic Neoplasms / Q000175:diagnosis*; D019459:Urothelium / Q000473:pathology*