1. Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany;
2. Heidelberg Ion-Beam Therapy Center (HIT), Heidelberg, Germany;
3. National Center of Radiation Research in Oncology (NCRO) Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany;
4. Department of Radiation Oncology, Allegheny General Hospital, Pittsburgh, PA, USA;
5. Department of Radiation Oncology, Mayo Clinic, Scottsdale, AZ, USA;
6. Department of Radiation Oncology, University of Maryland Medical Center, Baltimore, MD, USA;
7. Institute of Medical Biometry and Informatics (IMBI), Heidelberg, Germany;
8. Department of Thoracic Surgery, Thoraxklinik Heidelberg University Hospital, Heidelberg, Germany;
9. Department of Thoracic Oncology, Thoraxklinik Heidelberg University Hospital, Heidelberg, Germany