This multi-centre, open label, prospective, pilot study was designed to assess the ability of BR55 to detect VEGFR2 in human prostate cancer by Ultrasound Molecular Imaging (USMI). The binding of BR55 to VEGFR2 (focal enhancement still visible after significant decrease in signal from circulating microbubbles seen) was assessed at USMI and VEGFR2 expression was to be confirmed by immunohistochemistry (IHC) analysis including VEGFR2 and CD31 staining.