1 King's Technology Evaluation Centre, School of Biomedical Engineering and Imaging Sciences, King's College London, London SE1 7EU, UK. Electronic address: anastasia.chalkidou@kcl.ac.uk.
2 National Institute for Health and Care Excellence, Manchester, UK.
3 Clinical Oncology Department, Weston Park Hospital, Sheffield, UK.
4 Department of Medical Physics and Biomedical Engineering, University College London, London, UK.
5 The Royal Marsden NHS Foundation Trust and the Institute of Cancer Research, London, UK.