Hi. I had radiotherapy after lumpectomy and lymph node clearance last year. It wasn't too bad at all at the time, although the room was cold because of the machines. I wasn't worried about having to take of my bra as the staff were lovely and made me feel completely at ease every session. During the treatment I felt ok, a bit tired but not that awful. Afterwards I had some discoloration and some blistering and soreness under my breast but they gave me gels and creams to put on it which helped loads. The fatigue didn't kick in straight away, only after a few weeks, so it's worth resting whenever you can. Now I have a 'suntan' underneath and some pock marks on the breast itself but I moisturise every day and the skin seems ok apart from that. 

Hope your treatment goes well. x