1. Department of Surgery, Cardiff University, Cardiff, UK
2. Department of Surgery, Royal Marsden Hospital, London, UK
3. Department of Surgery, Leeds General Infirmary, Leeds, UK
4. Department of Surgery, Royal Derby Hospital, Derby, UK
5. Department of Nuclear Medicine, St George's Hospital, London, UK
6. Department of Primary Care and Public Health, Cardiff University, Cardiff, UK
7. Department of Surgery, Warwick Hospital, Warwick, UK
8. Department of Surgery, Royal Free and University College Medical School, University College London, London, UK