I say this as an emergency physician in the latter portion of my residency and not as a radiation oncologist, so caveat lector.
In short, no. Different modalities, different reasons. Different strengths and weaknesses. Not all malignancies are created equal in location, aggressiveness, how amenable they are to various therapies, and a number of other things. I do think it will grow in popularity, yes. But I wouldn't feel comfortable saying it'll supersede current radiation-based approaches. Certainly not to the point that it should sway you, should you think many years from now the way you think currently, from pursuing radiation oncology.
My two cents.