University of Newcastle, University of Newcastle, affiliation not provided to SSRN, Trans Tasman Radiation Oncology Group, University of Newcastle, affiliation not provided to SSRN, affiliation not provided to SSRN, affiliation not provided to SSRN, Nepean Hospital, affiliation not provided to SSRN, affiliation not provided to SSRN, Nepean Hospital, affiliation not provided to SSRN, Health New Zealand Waikato, Peter MacCallum Cancer Centre, affiliation not provided to SSRN, affiliation not provided to SSRN, University Hospital, Geelong - Andrew Love Cancer Centre, affiliation not provided to SSRN, affiliation not provided to SSRN, University of Otago - Christchurch Hospital, affiliation not provided to SSRN, Calvary Mater Newcastle, University College London and Calvary Mater Newcastle