1 The Institute of Cancer Research, London, UK; Head and Neck Unit, The Royal Marsden, London, UK. Electronic address: [email protected].
2 Leeds Cancer Centre, St James's Institute of Oncology, Leeds Teaching Hospital NHS Trust, Leeds, UK.
3 Department of Clinical Oncology, The Christie NHS Foundation Trust, Manchester, UK; Division of Cancer Sciences, The University of Manchester, Manchester, UK.
4 Head and Neck Unit, The Royal Marsden, London, UK; Division of Radiotherapy and Imaging, The Institute of Cancer Research, London, UK.