¹Kings College London, School of Biomedical Engineering and Image Sciences, London, United Kingdom; ²Guy's and St Thomas' NHS Foundation Trust, Head and Neck Surgery, London, United Kingdom

¹University of Oslo, Department of Physics, Oslo, Norway; ²University of Oslo, Institute of Oral Biology, Oslo, Norway; ³Oslo University Hospital, Department of Medical Physics, Oslo, Norway

(1)BC Cancer Agency - Southern Interior, Radiation Oncology, Kelowna, Canada;(2)NRG Oncology, Statistics and Data Management Centre, Philadelphoa, USA;(3)Mayo Clinic, Radiation Oncology, Rochester, USA;(4)Thomas Jefferson University Hospital, Urology, Philadelphia, USA;(5)University of Tennessee Health Science Centre, Pathology, Memphis, USA;(6)John Muir Health Systems, Radiation Oncology, Walnut Creek, USA;(7)Sunnybrook Health Sciences Centre- Odette Cancer Centre, Radiation Oncology, Toronto, Canada;(8)Cross Cancer Institute, Radiation Oncology, Edmonton, Canada;(9)Centre Hospitalier Universitaire de Quebec, Radiation Oncology, Quebec, Canada;(10)Princess Margaret Cancer Centre- University Health Network, Radiation Oncology, Toronto, Canada;(11)Washington University School of Medicine, Radiation Oncology, St Louis, USA;(12)Helen Diller Family Comprehensive Cancer Center- University of California, Radiation Oncology, San Francisco, USA;(13)Cancer Centers of Northern Arizona, Radiation Oncology, Sedona, USA;(14)Valley View Hospital Cancer Centre- Emory University, Radiation Oncology, Atlanta, USA;(15)Fox Chase Cancer Center, Radiation Oncology, Philadelphia, USA;(16)Helen F Graham Cancer Center- Christiana Care, Radiation Oncology, Newark, USA;(17)Cedar Sinai, Radiation Oncology, Los Angeles, USA;

¹St Luke's Radiation Oncology Network, Radiation Oncology, Dublin, Ireland; ²Nuffield Department of Population Health, University of Oxford, Medical Physics, Oxford, United Kingdom; ³Guy’s and St Thomas’ NHS Foundation Trust, Medical Physics, London, United Kingdom; ⁴Nuffield Department of Population Health, University of Oxford, Clinical Oncology, Oxford, United Kingdom; ⁵Oxford Cancer Centre, Oxford University Hospitals NHS Foundation Trust, Clinical Oncology, Oxford, United Kingdom; ⁶Trinity St James’s Cancer Institute, St. James’s Hospital, Radiation Oncology, Dublin, Ireland; ⁷Trinity College Dublin, School of Medicine, Dublin, Ireland; ⁸St Luke’s Radiation Oncology Network, Radiation Oncology, Dublin, Ireland

¹Guy's and St Thomas' NHS Foundation Trust, Department of Radiotherapy, London, United Kingdom

¹Hospital Universitario Puerta de Hierro Majadahonda, Medical Physics Department, Madrid, Spain; ²Hospital Universitario Puerta de Hierro Majadahonda, Medical Physics Deparment, Madrid, Spain; ³Hospital Universitario Puerta de Hierro Majadahonda, Medical Physics, Madrid, Spain