Welcome to OCF! You have come to the right place for info and support. With yoru wife being 8 months post rads, she is still in the recovery phase with lots of improvements still to happen up until about the 2 year post rad mark.

I know all about the white tongue. Ive had that happen to me many times and it can be quite painful. I called it grey tongue, but yes white is a good description too. Its from lack of circulation or it happens when its cold outside. Im in Pennsylvania where winters (to me) can be very cold its happened to me when I go outside to shovel snow. The longer it stays white (or grey) the more it can hurt when the circulation starts working again. At least thats what Ive experienced. I didnt get as far as you did with researching it to find out what the phenomenon is called. I havent had it happen to me in a long time. Since Im now almost 10 years post rads, I cant remember what my ENT told me about it. Make sure you ask your wifes doctors on her next appointment. Or if this continues to happen for extended periods of time then go get it checked out by her doc. Please come back and post what they tell you after the appointment as Im sure its not only your wife and I who have had this happen.

Thank you!