Concur with above post.
One mistake I made during my aways was I concentrated on learning rad/onc specific stuff (physics, management) when I was asked more about anatomy, basic workup, classic presentations of diseases, etc... Your attendings and residents know you're a medical student and are more likely to ask you the location of the motor strip or a pelvic anatomy question than about studies on altered vs conventional fractionation for H&N cancers.