We’ve been doing this for several years now and published our methods last year. Here is the link to our paper. https://pubmed.ncbi.nlm.nih.gov/32196944/
We also explored the dosimetric consequences of the intra-fraction motion if it had not been corrected and found that it doesn’t matter a whole lot to the ITV dose. We presented this at ASTRO in 2019. https://www.redjournal.org/article/S0360-3016(19)31654-2/fulltext