Dear hemme, There could be a number of reasons for this happening not directly related to the
radiationCystitis - noninfectious
Radiation therapy,
tamoxifenTamoxifen
Tamoxifen citrate or megace. For example; this could be a fungal infection, with your body being more susceptable to infection being on treatment or an underlying circulation problem. Make sure you bring it to the attention of your doctor so they can evaluate what is happening and can recommend appropriate treatment.