Do you know what the radiotherapy is directed at?
These are both possible treatments, but currently rare for advanced prostate cancer. There is new-ish evidence to show they can be very beneficial, but this hasn't gone mainstream on the NHS yet.
I'm guessing you are being offered this because they can't do chemo?
Has anyone mentioned abiraterone or enzalutamide drugs? They might also not be possible because of liver transplant, but I don't know.