1. 1Department of Epidemiology, The Netherlands Cancer Institute, Amsterdam, The Netherlands
2. 2Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center, Rotterdam, The Netherlands
3. 3Department of Radiation Oncology, Leiden University Medical Center, Leiden, The Netherlands
4. 4Department of Radiotherapy, University Medical Center Utrecht, Utrecht, The Netherlands
5. 5Department of Hemato-Oncology, Catharina Cancer Institute, Eindhoven, The Netherlands
6. 6Department of Internal Medicine, Adrz, Goes, The Netherlands
7. 7Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands