Extreme fatigue; irritation; dry, red skin; heavy or tight feeling in treated area; decreased sensation; and appetite loss are some side effects of radiation therapy. Dr. Marcio Fagundes, Medical Director of Radiation Oncology at Miami Cancer Institute, points out that irritation of the skin is the most common side effect.

He explains radiation therapy can also cause swelling and inflammation of the skin, and fatigue, because patients will come in on a daily basis for several weeks.