¹Mayo Clinic, Radiation Oncology, Rochester, USA

(1)Complejo Hospitalario Universitario Badajoz, Oncologia Radioterápica, Badajoz, Spain;

¹MD Anderson Cancer Center, Radiation Oncology, Houston, USA; ²MD Anderson Cancer Center, Radiation Oncology , Houston, USA

¹Medisch Spectrum Twente, Radiotherapy, Enschede, The Netherlands; ²University of Twente, Faculty of Technical Medicine, Enschede, The Netherlands; ³University of Twente, Faculty of Electrical Engineering, Mathematics and Computer Science (EEMCS), Robotics and Mechatronics (RAM), Enschede, The Netherlands

(1)Paul Scherrer Institute, Center for Proton Therapy, Villigen, Switzerland;(2)ETH Zürich, Department of Physics, Zürich, Switzerland;(3)University Medical Center Groningen, Department of Biomedical Sciences of Cells and Systems- Section Molecular Cell Biology, Groningen, The Netherlands;(4)University Medical Center Groningen, Department of Radiation Oncology, Groningen, The Netherlands;(5)University Hospital of Geneva, Department of Radiation Oncology, Geneva, Switzerland;(6)University Hospital of Zürich, Department of Radiation Oncology, Zürich, Switzerland;(7)Inselspital Universitätsspital Bern, Department of Radiation Oncology, Bern, Switzerland;

(1)Netherlands Cancer Institute, Radiotherapy, Amsterdam, The Netherlands;

(1)Yonsei Cancer Center, Radiation Oncology, Seoul, Korea Republic of;

(1)VU University Medical Center, Department of Radiation Oncology, Amsterdam, The Netherlands;