Cyberknife 3 versus 5 sessions

[notaclone13]

I have noticed that some people undergoing treatment with Cybeknife are having 3 sessions, while others are having 5 sessions. Notably, folks treated at Stanford appear to be getting only 3 sessions. I believe my doctor mentioned 5 sessions, although I will confirm that when I see him in a couple of days.  Anyone have any insight into why the difference in the number of sessions?