1. Department of Medical Imaging, Nuclear Medicine, Radboud university medical center, Radboud Institute for Molecular Life Sciences, 6525GA Nijmegen, The Netherlands
2. Organic Chemistry, Radboud University Nijmegen, Institute for Molecules and Materials, 6525XZ Nijmegen, The Netherlands
3. Department of Nuclear Medicine, University Hospital Bonn, 53127 Bonn, Germany