To eradicate any cancer cells that may potentially remain after surgery or chemotherapy, many breast cancer patients also undergo radiation therapy. All patients experience unfortunate side effects including skin irritation, and sometimes peeling and blistering. Patients can also develop permanent discoloration of the skin and thickening of the breast tissue months, or even years, after treatment. There is currently no method to predict the severity of these acute and late effects, and even current evaluation of these effects are based on subjective scoring.