Optical Coherence Tomography as a Tool for In Vivo Staging and Grading of Upper Urinary Tract Urothelial Carcinoma: A Study of Diagnostic Accuracy

Purpose: Biopsies and cytology are cornerstones in the diagnosis of upper urinary tract urothelial carcinoma. However, a high rate of nondiagnostic biopsies, tumor upgrading and tumor up staging after nephroureterectomy has been observed. In this prospective in vivo study we evaluated the diagnostic accuracy of optical coherence tomography for the grading and staging of upper tract urothelial carcinoma. Materials and Methods: A total of 26 patients underwent diagnostic ureterorenoscopy including biopsies and optical coherence tomography, followed by nephroureterectomy or segmental ureter resection. The sensitivity, specificity, negative predictive value and positive predictive value of upper tract urothelial carcinoma grading and staging by optical coherence tomography were evaluated according to the STARD (Standards for Reporting of Diagnostic Accuracy) initiative and the second stage (2a and 2b) of the IDEAL model. For tumor staging a 2 x 2 table for sensitivity and specificity was calculated. For tumor grading the Wilcoxon rank sum test was used to test mu(oct) in low and high grade lesions followed by ROC analysis for sensitivity and specificity. Results: In 83% the staging of lesions was in accordance with final histopathology. Sensitivity and specificity analysis for tumor invasion was 100% and 92%, respectively. Tumor size greater than 2 mm and inflammation were risks for false-positives. For low and high grade lesions median moct was 2.1 and 3.0 mm(-1), respectively (p <0.01). ROC analysis showed a sensitivity of 87% and a specificity of 90% using a mu(oct) cutoff of 2.4 mm(-1). Conclusions: This report describes optical coherence tomography as a real-time, intraoperatively diagnostic modality in the diagnostic evaluation of upper tract urothelial carcinoma. We confirmed the ability of optical coherence tomography to visualize, grade and stage urothelial carcinoma in the upper urinary tract