affiliation not provided to SSRN, affiliation not provided to SSRN, Fondazione IRCCS Istituto Nazionale dei Tumori, affiliation not provided to SSRN, Manchester Academic Health Sciences Centre - The Christie NHS Foundation Trust, Aarhus University - Aarhus University Hospital, Erasmus University Medical Center Rotterdam - Erasmus MC Cancer Institute, University of Groningen - University Medical Center Groningen, affiliation not provided to SSRN, Holland Proton Therapy Centre, affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, University College London - University College London Hospitals NHS Foundation Trust, affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, University of Oslo - Oslo University Hospital, affiliation not provided to SSRN, Maastricht University, affiliation not provided to SSRN, University of Bergen - Haukeland University Hospital, Umeå University - Department of Radiation Sciences, affiliation not provided to SSRN, University of Oslo - Oslo University Hospital, KU Leuven, University of Bergen - Haukeland University Hospital, affiliation not provided to SSRN, affiliation not provided to SSRN, Manchester Academic Health Sciences Centre - The Christie NHS Foundation Trust, affiliation not provided to SSRN, University College London - University College London Hospitals NHS Foundation Trust, European Institute of Oncology (IEO) IRCCS - Department of Radiation Oncology, affiliation not provided to SSRN, affiliation not provided to SSRN, KU Leuven and affiliation not provided to SSRN

University College London - University College London Hospitals NHS Foundation Trust, University College London - University College London Hospitals NHS Foundation Trust, University College London - University College London Hospitals NHS Foundation Trust, The University of Western Australia - Fiona Stanley Hospital, University College London - University College London Hospitals NHS Foundation Trust, University College London - University College London Hospitals NHS Foundation Trust, University College London - University College London Hospitals NHS Foundation Trust, University College London - University College London Hospitals NHS Foundation Trust, University College London - University College London Hospitals NHS Foundation Trust, University College London - University College London Hospitals NHS Foundation Trust, University College London - University College London Hospitals NHS Foundation Trust and University College London - University College London Hospitals NHS Foundation Trust