Financial & competing interests disclosure
RJ Ellis has received research funding from Elekta AB and Phillips. L Ponsky has received research grants from Accuray. SS Lo has received travel expenses and honorarium from Varian Medical Systems and Accuray and research support from Elekta AB. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.
No writing assistance was utilized in the production of this manuscript.
Supplementary data
To view the supplementary data that accompany this paper please visit the journal website at: www.tandfonline.com/doi/suppl/10.2144/000112170