1. Department of Nuclear Medicine University Hospital Münster Albert‐Schweitzer‐Campus 1 Münster 48149 Germany
2. German CyberKnife Centre Senator‐Schwartz‐Ring 8 Soest 59494 Germany
3. European Institute for Molecular Imaging University of Münster Waldeyerstr. 15 Münster 48149 Germany
4. Magnetic Detection and Imaging Group University of Twente Drienerlolaan 5 Enschede 7522 NB The Netherlands