Your practice will have an outside consultant called a Medical Physics Expert/Radiation Protection Advisor. You can ask them anything which you are not sure of regarding xrays.
We emailed our Radiation Protection Advisor/MPE this question and have kept a copy of his response in our Radiation Protection Folder. He informed us it is fine for this information to be kept only within the patient records as long as the registered manager can obtain the information and submit it to the Secretary of State if requested.
Read below the section on dose estimates.
www.fgdp.org.uk/news/updated-new-regulat...irr17-and-irmer18ead
If you're interested read the IRMER2018. There should be a copy in your radiation folder.