Mieke Bus

86 Chapter 6 Abstract Introduction Minimal invasive endoscopic treatment for upper urinary tract urothelial carcinoma (UUT- UC) is advocated in patients with low risk disease and limited tumorvolume. Diagnostic ure- terorenoscopy combined with biopsy is the diagnostic standard. This study aims to evaluate two alternative diagnostic techniques for UUT-UC: Optical Coherence Tomography (OCT) and Endoluminal Ultrasound (ELUS). Material & Methods Following nephroureterectomy, OCT, ELUS and CT were performed of the complete neph- roureterectomy specimen. Visualization software (AMIRA®) was used for reconstruction and co-registration of CT, OCT and ELUS. Finally, CT was used to obtain exact probe localization. Co-registered OCT and ELUS datasets were compared with histology. Results Co-registration with 3D CT makes exact data matching possible in this ex-vivo setting in order to compare histology with OCT and ELUS. In OCT images of normal appearing renal pelvis and ureter, urothelium, lamina propria and muscularis were visible. With ELUS all ana- tomical layers of the ureter could be distinguished, besides the urothelial layer. ELUS iden- tified suspect lesions although exact staging and differentiation between non-invasive and invasive lesions was not possible. Conclusion OCT provides high-resolution imaging of normal ureter and ureter lesions. ELUS however is of limited value as it cannot differentiate between non-invasive and invasive tumors.