1 National Center for Tumor Diseases (NCT/UCC), Dresden, Germany. alexander.zwanenburg@nct-dresden.de.
2 OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany. alexander.zwanenburg@nct-dresden.de.
3 German Cancer Research Center (DKFZ), Heidelberg, Germany. alexander.zwanenburg@nct-dresden.de.