Mieke Bus

52 Chapter 4 Abstract Introduction Knowledge on tumor stage and grade is paramount for treatment decision in Upper Urinary Tract Urothelial Carcinoma (UTUC), but cannot be accurately assessed by current techniques. Optical Coherence Tomography (OCT) is a technique, which can hypothetically provide the urologist with real-time intra-operative information on tumor grade and stage. In this pilot study the first results of OCT in grading and staging of UTUC are presented. Material & Methods Eight consecutive patients underwent URS for UTUC suspicion or follow-up. OCT datasets were intra-operatively obtained from the ureter and pyelum. All patients eventually under- went nephroureterectomy. OCT staging was performed by visual inspection of lesions found on OCT images and OCT grading by quantification of the OCT signal attenuation (µ oct [mm - 1 ]) on lesions and compared with histopathological diagnosis. AWilcoxon rank sum test was used for statistical analysis. Results Seven in-vivo OCT diagnoses on staging were in accordance with histology. In the eighth patient tumor thickness transcended OCT imaging depth range and was therefore incon- clusive on invasiveness. For grading, median (interquartile range) µ oct for grade 2 lesions was 1.97 mm -1 (1.57-2.30) and 3.53 mm -1 (2.74-3.94) for grade 3 (p-value <0.001). Healthy urothe- lium was too thin to reliable determine µ oct . Conclusions OCT is a promising minimally invasive tool for real time intra-operative optical diagnostics for tumors in the upper urinary tract. Our study results warrant future research to determine in a larger sample size grading and staging accuracy of OCT and the possible implementation of OCT in the diagnostic algorithm of UTUC.