Leonor,I only had one lot of radiation(lasting 6 weeks)back in 2003.After that.for 6 years, my mammograms were clear.Then last year's mammogram showed a 3cm area of cancer.It was in the same breast,same spot,similar pathology.My doctor says there may have been a stray cell left behind. I think there could be 2 explanations: firstly the supposedly clear margins from the lumpectomy were not looked at properly.Or perhaps the radiation excellerated the growth.I will never know the reason it came back and I've stopped worrying about it cos it does your head in! These are questions you might want to ask your radio oncologist before you decide.
Tonya xx