Top Three Radiation Side Effects

By Elizabeth Falkenberg, M.D., radiation oncologist at Alliance Cancer Care

Radiation sounds scary even before the doctor begins to talk about side effects. Will I glow in the dark? NO, but that would be cool! Radiation is an x-ray treatment, designed to target a particular area of the body. In contrast, chemotherapy is a medication that is given by IV or mouth and goes all over the body. Side effects are very different with radiation being targeted to one location in the body versus the potential of being all over the body. When your doctor first talks about the side effects of radiation, these are acute side effects – ones that happen during treatment. Here we review the top three acute side effects of radiation and how to manage them.

Fatigue – Radiation therapy causes fatigue by the body releasing proteins called cytokines. Radiation typically does not drop your blood counts to cause fatigue, like some types of chemotherapy that affect the bone marrow. Instead, your body needs to focus its energy to heal the site being treated and releases inflammatory markers. You, the patient, then feel fatigued. It usually takes about 2-3 weeks of radiation to notice fatigue because it is a gradual “build-up” side effect. Most fatigue from radiation therapy is mild. Many patients continue to work full-time and continue their previous exercise regimen.

If you experience fatigue during treatment, try to do your normal activities but take breaks to rest. Some patients need to go to sleep earlier at night. Other patients just need 30-40 minutes to rest, and then they feel like getting up and back to normal activities. We suggest daily exercise to increase function and decrease fatigue, as exercise decreases inflammation in the body and can improve quality of life. We also recommend staying well-hydrated during radiation.

Redness/rash/sunburn of the skin – Radiation may cause skin changes, but these are only seen where the beam of radiation is going. These changes are also gradually “building up” during radiation treatment. Redness or sunburn in the skin at the end of radiation is only a side effect, as the x-rays do not work by “burning” the cancer. Radiation x-rays work at the cellular level to cause a break in the tumor cells’ DNA so the tumor cell cannot grow or replicate. The redness or darkening of the skin near your tumor and treatment site is the reaction of the skin, and then these normal cells heal slowly over time, similar to a sunburn at the beach. We usually treat skin redness with moisturizing lotions and then treat itching or rash with a steroid cream. Gentle massage with lotion can help preserve the elasticity of the skin as it heals. Your hair, which is part of the skin, may fall out in the location of the radiation changes. This is sometimes temporary and sometimes permanent.

Diarrhea/nausea– Again, radiation causes side effects specific to the location of the treatment. Patients who are receiving treatment to the pelvis for prostate cancer, rectal cancer, cervical cancer, endometrial cancer, and others can experience diarrhea. If you are receiving chemotherapy at the same time, diarrhea can be exacerbated. We usually recommend using Imodium for diarrhea, or your doctor can prescribe something stronger if needed. Gas-X can help with symptoms of bloating and gas. If the radiation therapy is delivered to the abdomen or stomach area, this can cause mild nausea or reflux. We recommend anti-acids and nausea medicine daily before treatment to help prevent nausea if you experience it after the first couple of treatments.

Your doctor will discuss side effects relevant to the area of the body that will receive radiation therapy. Always ask questions if you are unsure if the symptom you are having is due to your radiation treatment.