title: Volumetric in vivo visualization of upper urinary tract tumors using optical coherence tomography: a pilot study.
abstract: OBJECTIVE
  Knowledge of tumor stage and grade is paramount for treatment decision making in cases of upper urinary tract urothelial carcinoma but this condition cannot be accurately assessed by current techniques. Optical coherence tomography can hypothetically provide the urologist with real-time intraoperative information on tumor grade and stage. In this pilot study we report what are to our knowledge the first results of optical coherence tomography for grading and staging upper urinary tract urothelial carcinoma.
  
  
  METHODS
  Eight consecutive patients underwent ureterorenoscopy for suspicion or followup of upper urinary tract urothelial carcinoma. Optical coherence tomography data sets were intraoperatively obtained from the ureter and renal pelvis. All patients eventually underwent nephroureterectomy. Optical coherence tomography staging was done by visual inspection of lesions found on optical coherence tomography images. Optical coherence tomography grading was done by quantifying optical coherence tomography signal attenuation in mm(-1) on lesions and comparing results with the histopathological diagnosis. The Wilcoxon rank sum test was used for statistical analysis.
  
  
  RESULTS
  For 7 in vivo optical coherence tomography diagnoses staging was in accordance with histology. In patient 8 tumor thickness transcended optical coherence tomography imaging depth range and, therefore, invasiveness findings were inconclusive. For grading the median attenuation coefficient for grade 2 and 3 lesions was 1.97 (IQR 1.57-2.30) and 3.53 mm(-1) (IQR 2.74-3.94), respectively (p<0.001). Healthy urothelium was too thin to reliably determine the attenuation coefficient.
  
  
  CONCLUSIONS
  Optical coherence tomography is a promising, minimally invasive tool for real-time intraoperative optical diagnosis of tumors in the upper urinary tract. Our results warrant future research in a larger sample size to determine the accuracy of grading and staging by optical coherence tomography, and its possible implementation in the diagnostic algorithm for upper urinary tract urothelial carcinoma.
authors: Department of Urology, Academic Medical Center, Amsterdam, The Netherlands. Electronic address: m.t.bus@amc.uva.nl.
authors: Mieke T J
authors: MT
authors: Bus
authors: Berrend G
authors: BG
authors: Muller
authors: Daniel M
authors: DM
authors: de Bruin
authors: Dirk J
authors: DJ
authors: Faber
authors: Guido M
authors: GM
authors: Kamphuis
authors: Ton G
authors: TG
authors: van Leeuwen
authors: Theo M
authors: TM
authors: de Reijke
authors: Jean J M C H
authors: JJ
authors: de la Rosette
mesh_terms: D000368:Aged; D002295:Carcinoma, Transitional Cell / Q000473:pathology*; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011446:Prospective Studies; D041623:Tomography, Optical Coherence; D047368:Tumor Burden; D014516:Ureteral Neoplasms / Q000473:pathology*
keywords: 3-dimensional; 3D; CIS; OCT; PDD; URS; UUT; UUT-UC; UUT-urothelial carcinoma; carcinoma; carcinoma in situ; diagnosis; optical coherence; optical coherence tomography; photodynamic diagnosis; tomography; upper urinary tract; ureterorenoscopy; urinary tract; urothelium