1 UCL Cancer Institute, University College London, London WC1E 6AG, UK; Head and Neck Centre, University College London Hospitals NHS Trust and Barts Health NHS Trust, London, UK. Electronic address: m.lechner@ucl.ac.uk.
2 UCL Cancer Institute, University College London, London WC1E 6AG, UK.
3 Centre for Health Policy and Management, Trinity College, Dublin, Ireland.
4 Department of ENT, Cambridge University Hospitals NHS Trust, Cambridge, UK.