Government of the United Kingdom - Oxford Cancer Centre, Cardiff University - Centre for Trials Research, Cardiff University - Centre for Trials Research, Cardiff University - Centre for Trials Research, Cardiff University - Wales Research and Diagnostic Positron Emission Tomography Centre (PETIC), Cardiff University - Centre for Trials Research, University Hospitals Bristol - University Hospitals Bristol and Weston NHS Foundation Trust, University of Southampton - Southampton Clinical Trials Unit, Swansea Bay University Health Board - South West Wales Cancer Centre, University of Cambridge - Department of Oncology, Cardiff University - Centre for Trials Research, University of Oxford - MRC Oxford Institute for Radiation Oncology, Cardiff University - Centre for Trials Research, Manchester Academic Health Sciences Centre - The Christie NHS Foundation Trust, Government of the United Kingdom - Hull University Teaching Hospitals NHS Trust, Cardiff University - Centre for Trials Research, Manchester Academic Health Sciences Centre - The Christie NHS Foundation Trust, Cardiff University - School of Engineering, University College London - Department of Medical Physics and Biomedical Engineering and Velindre Cancer Centre