1. Department of Radiation Oncology; Erlangen University Hospital; Erlangen Germany
2. Department of Radiotherapy; University Hospital; Rostock Germany
3. Department of Radiotherapy and Radiooncology; University Hospital Carl Gustav Carus; Dresden Germany
4. Department of Radiotherapy and Radiooncology; Medical Department; Georg-August University; Göttingen Germany
5. Department of Radiooncology; University Hospital; Tübingen Germany
6. Department of Radiotherapy and Radiooncology; University Hospital; Ulm Germany
7. Department of Radiotherapy and Oncology; University Hospital, Goethe University; Frankfurt/Main Germany
8. Department of Radiotherapy and Radiooncology; Saarland University Medical Center; Homburg/Saar Germany
9. Centre for Radiotherapy and Radiooncology; Westerstede Germany