Hi Brendan - I haven't heard of that particular issue but this treatment does crazy things to us! I have a tingly numbness that shoots down my spine as a result of radiation every time I look down.
I've found my GP to not be the best person to follow-up with - my MO - by far - has been able to give me reasons for weird side effects while others have seemed to just take their best guess! Not at all reassuring!

I can't help but wonder if there isn't something more that your team can do about your nausea and vomtting. I think I was on 3 different meds for nausea - given to me during chemo by IV and then afterwards by mouth and they did the trick - oddly enough - I looked forward to chemo cause I felt better the 2 days afterwards than I did all week - no nausea and the steroids gave me a blessed break from the fatigue. May want to see if there's something different that can be done for your nausea - the idea of vomitting with a radiation burned mouth makes me cringe!

Take good care!