Timo Soeterik

22 CHAPTER 1 prediction of side-specific EPE. At the time of our study, a nomogram including side- specific MRI information was developed by Martini and colleagues, showing good model performance when applied in the development cohort. 54 To determine if this nomogram can be used safely in external populations, we will perform an external validation study (Chapter 6) . To further investigate our assumption that inclusion of MRI may improve the accuracy of nomograms for the prediction of EPE, we aimed to develop and externally validate novel nomograms for the prediction of side-specific EPE. The nomograms will include MRI information, biochemical parameters and histopathological biopsy characteristics. The performance of four nomograms, each including different combinations of parameters, will be established and compared (Chapter 7) . In Chapter 8 , we will evaluate if cT assessed by MRI can replace cT assessed by DRE as an impute parameter of two established nomograms used for LNI risk prediction (MSKCC 2018 preoperative nomogram and the Briganti 2012 nomogram). We assumed that cT assessed by MRI could potentially be more accurate compared with DRE. However, question remains if this would also lead to improved LNI risk prediction; since both nomograms are originally developed using cT assessed by DRE. Therefore, we will assess how the incorporation of cT assessed by MRI impacts the accuracy of nomogram-based risk prediction of prostate cancer LNI. Part V General Summary and Discussion Part V includes the General Summary (Chapter 9) , the Discussion of the main findings presented in chapter 2-8 and Future Perspectives (Chapter 10) .