K--
I had complications after radiation (my throat closed up completely), and the scans later did show some activity, but my doctors were convinced that it was consistent with the inflamation in my throat. In fact, my ENT and I saw the scans before they had been read by radiology, which he said was good since the radiologist would identify them as cancer, while we knew it was something else.
I would question the doctor more carefully if you are not satisfied with the "wait and see" answer. But you should know that other things besides cancer can show up on these things. You could get a second opinion on the reading, but at some point you just have to trust your doctors on these interpretations. Maybe a more detailed explanation is all you really need?
Best of luck to you!
Susan