[1] Royal Marsden Hosp, Clin Oncol, London, England
[2] Inst Canc Res Radiotherapy & Imaging, Sutton, Surrey, England
[3] Massachusetts Gen Hosp, Boston, MA USA
[4] Harvard Med Sch, Radiat Oncol, Boston, MA USA
[5] Hampton Univ Proton Therapy Inst, Phys & Dosimetry, Hampton, VA USA
[6] Christie NHS Fdn Trust, Med Phys, Manchester, Lancs, England
[7] Royal Marsden Hosp, Clin Oncol Breast, London, England
[8] UCL, Med Phys, London, England
[9] UCL, Hosp NHS Fdn Trust, Radiotherapy, London, England