Has anyone had effects of radiotherapy months after . I have now been told the redness and heat and tenderness on the opposite side of where tumour was removed on same right breast is a reaction to radiotherapy 6 months after I had finished my treatment, I have been to hospital had a mammogram and thank the Lord it was clear. Some days redness and swelling is worse than others. The bcc nurse said she feels it may be gone by next visit I see them next year.