1. Department of Radiotherapy, The Christie Hospital NHS Trust, Manchester, UK
2. Department of Clinical Oncology, The Clatterbridge Cancer Centre, Liverpool, UK
3. Department of Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK
4. Department of Clinical Oncology, The Christie NHS Foundation Trust, Manchester, UK
5. Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester Academic Health Science Centre, Manchester, UK