@jardinera25 Even for photon, the “beam” is huge, like maybe 18” in diameter? Don’t quote me, but your team uses scans of your breast/arm/chest/area of concern, and uses beautiful mathematics to program little lead fingers that open or close the beam in 3D to focus where they want. The advantage is that Proton beam can be further programmed to stop where needed whereas Photon just kind of goes thru. I hope I did not butcher the description of it, but don’t think of a laser pointer size beam; think much larger and sculpted for you and you only. Your radiologist should be able to explain it better and even provide visuals of your plan. Very interesting medicine!