Mieke Bus

68 Chapter 5 Abstract Introduction Biopsies and cytology are cornerstones in the diagnosis of upper urinary tract urothelial carcinoma (UTUC). However, a high rate of non-diagnostic biopsies, tumor upgrading and -staging after nephroureterectomy is observed. In this prospective in vivo study we aimed to evaluate the diagnostic accuracy of OCT for grading and staging of UTUC Material & Methods Twenty-six patients underwent diagnostic URS including biopsies and OCT imaging, fol- lowed by nephroureterectomy or segmental ureter resection. Sensitivity, specificity, negative predictive value and positive predictive value of UTUC grading and staging by OCT were evaluated according to the STARD initiative and second stage (2a and 2b) of the IDEAL model. For tumor staging 2x2 table for sensitivity and specificity was calculated. For tumor grading, the Wilcoxon-rank-sum-test was used to test µ oct in low- and high-grade lesions followed by ROC analysis for sensitivity and specificity. Results In 83% staging of lesions was in accordance with final histopathology. Sensitivity and spec- ificity analysis for tumor invasion was 100% and 92% respectively. Tumor size >2mm and inflammation were risk for false-positives. For low- and high-grade lesions, median µ oct was 2.1 mm -1 and 3.0 mm -1 (p-value <0.01) respectively. ROC-analysis showed sensitivity of 87% and specificity of 90% using a cut-off value µ oct of 2.4 mm -1 . Conclusion This report describes OCT as a real time, intra-operatively diagnostic modality in the diagnos- tic workup of UTUC. We confirmed the ability of OCT to visualize, grade and stage urothelial carcinoma in the upper urinary tract.