Now, what I've heard is, that in some cases, proton therapy is advantageous compared to photons, and of course the other way around in some other cases. I can see, that the Bragg peak of the proton curve is very sharp, which means, that in order to hit a tumour, with some size, you have to make a spread Bragg peak resulting in some higher dose in the plateau region, than then ~20% it is now. But I'm not sure that even that would result in a larger dose in that area, than if you were to use photons ?