Fijs W B van Leeuwen1,2, Henk G van der Poel3. 1. Interventional Molecular Imaging Laboratory, Department of Radiology, Leiden University Medical Center, Leiden, Netherlands. f.w.b.van_leeuwen@lumc.nl. 2. Department of Urology, Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Amsterdam, Netherlands. f.w.b.van_leeuwen@lumc.nl. 3. Department of Urology, Netherlands Cancer Institute - Antoni van Leeuwenhoek Hospital, Amsterdam, Netherlands.