Authors: Jolien Heukelom1, Jesper Grau Eriksen2, Amanda Webster3, Bartlomiej Tomasik4, Daan Nevens5, Jenny Bertholet6, Kathrine Røe Redalen7, Ludwig J Dubois8, Pierfrancesco Franco9, Sophie Perryck10, Steven Petit11
1GROW - School for Oncology and Reproduction, Maastricht University Medical Centre+, Department of Radiation Oncology (Maastro), Maastricht, The Netherlands; 2Aarhus University Hospital, Department of radiation oncology, Aarhus, Denmark; 3University College London Hospital , Radiotherapy and Proton Beam Therapy, London, United Kingdom; 4Faculty of Medicine, Medical University of Gdansk, Department of Oncology and Radiotherapy, Gdansk, Poland; 5Iridium Network, Wilrijk, Faculty of Medicine and Health Sciences, University of Antwerp, Department of Radiation Oncology, Antwerp, Belgium; 6Inselspital, Bern University Hospital, and University of Bern, Division of Medical Radiation Physics and Department of Radiation Oncology, Bern, Switzerland; 7Norwegian University of Science and Technology, Department of Physics, Trondheim, Norway; 8GROW - School for Oncology and Reproduction, Maastricht University, The M-Lab, Dept of Precision Medicine, Maastricht, The Netherlands; 9University of Eastern Piedmont, Department of Translational Sciences (DIMET), Novara, Italy; 10University Hospital Zurich, Department of radiation oncology, Zurich, Switzerland; 11Erasmus MC Cancer Institute, Department of Radiotherapy, Rotterdam, The Netherlands