1. First Department of Internal Medicine Center for Integrated Oncology Aachen Bonn Cologne Dusseldorf University of Cologne Cologne Germany
2. German Hodgkin Study Group (GHSG) University Hospital Cologne Cologne Germany
3. Department of Nuclear Medicine University of Cologne Cologne Germany
4. Department of Hematology, Oncology, Immunology, Palliative Medicine, Infectious Diseases and Tropical Medicine Munich Clinic Schwabing Munich Germany
5. Second Department of Internal Medicine University Hospital Würzburg Würzburg Germany
6. Department of Hematology and Stem Cell Transplantation West German Cancer Center University Hospital Essen University of Duisburg‐Essen Essen Germany