Mieke Bus

33 3 Introduction Contemporary steps in the diagnosis of Upper Urinary Tract Urothelial Carcinoma (UTUC) are based on imaging, ureterorenoscopy and obtaining histology/cytology. Although these techniques are considered “standard of care”, they have limitations. Radiological and cytological evidence on small and/or flat lesions are reported with a low accuracy. (1-3) Secondly ureterorenoscopy (URS) requires anaesthesia and does not provide real time information on stage and grade of the disease. Pathological diagnosis is often inconclusive due to the small samples that are obtained, mainly because of the limitations of the equipment. (4) Furthermore, carcinoma in situ (CIS) lesions are easily missed on URS due to their flat appearance. Consequently, a high rate of tumour upgrading and upstaging is reported following nephroureterectomy. (5) The standard treatment for UTUC has been open or laparoscopic nephroureterectomy. Recently, the EAU guidelines accepted conservative endoscopic treatment using ureter- orenoscopy for a select group of UTUC patients with low-volume, low-grade and low-stage disease. (6) To select patients eligible for endoscopic treatment, information on tumour stage and grade is essential. With the current diagnostic tools selection of patients for conservative treatment is still suboptimal. Novel optical diagnostic techniques, based on the interaction between light and tissue, have the potential to improve UTUC visualization. These inter- actions include scattering, absorption and fluorescence, all of which are characteristic for certain tissue types. Some of these techniques aim at improved visualisation of urothelial tumours (NBI, SPIES 1 , PDD), while other techniques aim at providing real time intra-operative information on tumour grade and stage (OCT, CLE). Most research on the application of optical diagnostics on urothelium has been done in the field of bladder cancer. (7, 8) In case of the upper tract however, the limited space in the ureter and the difficulty to reach the upper urinary tract creates an entire new spectrum of challenges for new optical techniques. In this systematic review the principles of these new optical techniques are described and their applicability in the diagnosis and treatment of UTUC and outline their feasibility and current clinical applications. In addition, we evaluate the relevant literature according to standard classifications. (9-12) 1 Currently known as IMAGE1 S™