Mieke Bus

4 63 low-grade, low-stage prior diagnosis, endoscopic laser fulguration can be applied. A draw- back of laser treatment is absence of specimens for pathology for definite diagnosis with associated risk of progression having occurred without being noticed. OCT measurements of these tumors may provide this diagnosis, so laser fulguration becomes a safer treatment modality. Random biopsies are taken to exclude or confirm CIS in case of negative URS findings and cytology pointing to high-grade malignancy. OCT may be of value guiding these biopsies. OCT is less suitable for screening of the complete ureter, since it has to be directed vis- ually to points of interest detected at ureteroscopy. Thus in the absence of visually suspect lesions, a combination of OCT with established optical diagnostics (i.e. photodynamic diag- nosis (PDD), narrow band imaging (NBI) or emerging techniques such as Raman spec- troscopy and Low-coherence Spectroscopy to direct to the region of interest may further increase the diagnostic potential. (22-25) OCT combined with PDD reduces false-positive biop- sies and increases specificity compared to PDD alone in the bladder. (26) Due to similarities between urothelial cancers of bladder and UUT, this combination may be applicable in the latter as well. This study is carried out according to the step 1 and 2a of the IDEAL model. This model has high potential for study design in surgical innovations. However, only recommendations regarding study design are described but reporting standards still need to be formulated. Several study designs could be considered to confirm the feasibility of OCT in UTUC. First of all, an extended in vivo study will have to confirm if OCT is able to differentiate between low-, high-grade and CIS lesions. Secondly, sensitivity and specificity should be determined. Finally by comparing OCT with established pre-operative and intra-operative methods like CT-scan, (selective) cytology and biopsies, the added value of OCT can be determined. As UTUC is not a common disease, studies as proposed above should preferably start as multi-centre studies in order to obtain a large study population. In conclusion, OCT is a promising new tool for optical diagnostics in upper urinary tract abnormalities. An extended in vivo human study which is about to commence in our centre, second step (2b) in the IDEAL protocol, will confirm if OCT is able to differentiate between low-grade, high-grade and CIS lesions. Secondly, sensitivity and specificity testing of OCT will be determined in nephroureterectomy specimens. Project support This study is funded with a grant provided by the Cure for Cancer foundation and Stichting Urologie 1973, which is gratefully acknowledged.