Dale has given you a very good picture of what happens with radiotherapy.I had a lumpectomy back in 2003 and was told I HAD to have radiation afterwards.I went for about 6 weeks and by the end I was quite tired and my boob was glowing like a hotplate but my skin never broke down.I had no problems afterwards with my lungs or heart.However,my boob was firmer and uncomfortable (not painful)from then on. Unfortunately,7 years later,I was in the 8% whose cancer returns in the same breast. So last year I had a mastectomy and chemo.You will find that radiation treatment is nowhere near as hard as chemo.It's scary at first but you get used to it after a few sessions and it doesn't hurt.If I could look into a crystal ball then I would have had a mastectomy in the first place but we don't know.I think you would be taking more of a risk if you don't have radiation- 8% is better odds than 30%.
Tonya xx