1. Department of Hematology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany;
2. Institute for Medical Informatics, Biometry, and Epidemiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany;
3. Department of Pathology, Hematopathology Section and Lymph Node Registry, University Hospital Schleswig-Holstein, Kiel, Germany;
4. Department of Nuclear Medicine, University Hospital Essen, University of Duisburg-Essen, Essen, Germany