So this radiotherapy lark?
Basically it'll involve I think a week and a half of daily doses, which as a pallative treatment, which won't cure it, but is meant to try and shrink it and reduce the pain that Dad gets when his arm feels numb from the cancer touching nerves.
So Dad's gonna get these daily doses, zapped into him, and it sadly enough won't lead to him coming over all Radioactive and Incredible Hulk-like.
Neither will there be any interesting side-effects like hair-loss, only tiredness and as The Brat said, "who's gonna know the difference then?"

If you're a statistics freak, we've been told that, there will be a 75% chance of this working and a 45% percent chance of side-effects.

So there you go, we also have thrilling booklets entitled "living at home when your cancer is advanced" (Or living at home when your cancers about to kill you off), this comes with a equally riveting sequel, "Caring at home when your cancer is advanced" (Possibly the saddest and most depressing thing I've ever forced myself to read)
And another about Financial help from the Macmillan Cancer people. (The Mothership already has plans about getting a new tumble dryer from them as our ones dying a slow and painful death)
(Look at that! A post that goes from radiotherapy, to dying to new tumble-dryers, It's all linked in a big circle!)