This was the same for my mother, she finished radiotherapy April 07, about 4 weeks ago her tounge became swollen along with her lips, looked like she had a plum in her mouth. I contacted the consultant by phone, he rang her GP who did a home visit. She has been taking steriods for the last 10 days and after about 4 days there was a noticable diffrence in the toiunge. It is not back to normal and may never be, but it is better and easier to understand what she is saying.