1 Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK.
2 The Christie NHS Foundation Trust, Manchester, and University of Manchester, UK.
3 Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK; Division of Cancer Sciences, University of Manchester, Manchester Cancer Research Centre, Manchester Academic Health Science Centre, UK.
4 Division of Cancer Sciences, University of Manchester, Manchester Cancer Research Centre, Manchester Academic Health Science Centre, UK.