1 Institute of Cancer Research-Clinical Trials and Statistics Unit (ICR-CTSU), London, United Kingdom; Division of Radiotherapy and Imaging, The Institute of Cancer Research, London, United Kingdom; The Royal Marsden, London, United Kingdom.
2 Division of Radiotherapy and Imaging, The Institute of Cancer Research, London, United Kingdom.
3 Division of Radiotherapy and Imaging, The Institute of Cancer Research, London, United Kingdom; The Royal Marsden, London, United Kingdom.
4 Institute of Cancer Research-Clinical Trials and Statistics Unit (ICR-CTSU), London, United Kingdom.