1. Department of Radiation Oncology University Hospital, LMU Munich 81377 Munich Germany
2. Department of Medical Physics, Faculty of Physics Ludwig‐Maximilians‐Universität München (LMU Munich) 85748 Garching bei München Germany
3. Rinecker Proton Therapy Center 81371 Munich Germany
4. Department of Radiology University Hospital, LMU Munich 81377 Munich Germany
5. Comprehensive Pneumology Center Munich (CPC‐M) German Center for Lung Research (DZL) 81377 Munich Germany
6. German Cancer Consortium (DKTK), Partner site Munich 81377 Munich Germany