Seeing upper tract urothelial carcinoma in a new light

The thesis ‘Seeing Upper Tract Urothelial Carcinoma in a New Light’ provides a collection of studies that explored the shortcomings of the current diagnostic approach to upper tract urothelial carcinoma (UTUC) and that investigated the use of novel optical techniques for UTUC diagnosis.
The thesis presents the first nationwide study to portray the high rate of upgrading of biopsy-based low-grade UTUC with regard to subsequent surgical resections. Furthermore, the thesis includes the first study to illustrate the diagnostic inaccuracy and the low inter-rater agreement of grade predictions based on the gross visual appearance of UTUC during digital ureterorenoscopy.
To address the current diagnostic shortcomings, efforts were made to advance the state of development of optical coherence tomography (OCT) and confocal laser endomicroscopy (CLE) for in-vivo diagnosis of UTUC. In this light, an improved OCT attenuation coefficient cut-off value for quantitative grading of UTUC was investigated, resulting in a promising diagnostic accuracy. Quantitative assessment of in-vivo CLE images enables grading of UTUC at a promising accuracy. Lastly, the feasibility of fluorescence in situ hybridization (FISH) for the detection of UTUC in 1 mL of upper urinary tract urine was proven. From a technical point of view, therefore, FISH of selectively collected upper tract urine could serve as a triage test to reduce the number of follow-up ureterorenoscopies after kidney-sparing surgery of UTUC.
The findings of this thesis should stimulate further efforts to advance the state of development of OCT, CLE and FISH towards clinical implementation for the diagnosis of UTUC. The future looks bright with optical biopsies.