I've seen some professors out there who list being board cert. in both radiation oncology and medical oncology. Are there fellowships out there for radiation oncology after residency (if not why? Is internal med residency that necessary for the fellowship?) or did these people do two residencies plus a fellowship? Do Radiation oncologists ever treat patients medically? I'm wondering because clinical oncologists (UK) supposedly treat patients both with chemo and radiation, but that doesn't seem to be the case here? Thanks for the answers!