Herbert Decaluwé1, Dirk De Ruysscher2, Thomas D'Amico3. 1. Department of Thoracic Surgery, University Hospitals Leuven, Leuven, Belgium; Department of Clinical and Experimental Medicine, Katholieke Universiteit Leuven, Leuven, Belgium. Electronic address: Herbert.decaluwe@uzleuven.be. 2. GROW School for Biology and Medical Oncology, Maastricht University Medical Center, Maastricht University, Maastricht, The Netherlands; Department of Radiation Oncology, MAASTRO Clinic, Maastricht, The Netherlands; Radiation Oncology, Katholieke Universiteit Leuven, Leuven, Belgium. 3. Department of Surgery, Division of Cardiovascular and Thoracic Surgery, Duke University Medical Center, Duke University, Durham, North Carolina.