Radiation therapy, a type of treatment that exposes patients to ionizing radiation, has a number of common side effects. Frequent complications of radiation therapy may include immediate issues such as skin irritation, nausea, and ulcers, as well as long-term side effects including fibrosis, skin thinning, and lymphedema. The side effects of radiation therapy can be limited by using the smallest dose of radiation possible, and can be alleviated by a number of medications. Many of the side effects of radiation therapy are unavoidable because radiation harms normal and abnormal cells alike.
Side effects of radiation therapy can develop immediately at the site where the radiation is administered. These local side effects can include skin redness, swelling and peeling. If areas such as the mouth are subject to radiation, ulcers can develop. Radiation of the gastrointestinal tract can cause diarrhea. Exposing the testes or ovaries to ionizing radiation can cause infertility, which can be temporary or permanent depending on the dose of radiation.
Other common side effects of radiation therapy develop over time. The tissue at the radiation site often never completely returns to normal. The skin, blood vessels, and lymphatic vessels may all lose some structural integrity, resulting in thin skin, hair loss, easy bruising, lymphedema, and fibrosis.
Some less common radiation side effects develop over time. Research has suggested that radiation to the heart increases the long-term risk for heart disease. Radiation therapy also increases the risk for cancers such as leukemia and lymphoma.
The best way to prevent the side effects of radiation therapy is to decrease exposure to radiation. A basic tenet of all radiation administration is to use the smallest effective dose in the smallest area of the body to prevent as many side effects of radiation therapy as possible. Various techniques have been developed to focus the radiation on a small area.
Other side effects of radiation therapy can be dealt with as symptoms arise. A number of lotions and creams can alleviate pain associated with skin redness or peeling. Numbing medications can decrease the pain associated with oral ulcers. Anti-emetic medications can decrease nausea and vomiting.
The use of radiation therapy relies on its ability to harm the genetic material of cells, the deoxyribonucleic acid (DNA). Damage to the DNA results in cell death, whether it's the affected cell or the affected cell’s offspring that dies. Ionizing radiation kills non-selectively, meaning both healthy and cancerous cells can be harmed. The death of normal cells results in many of the side effects associated with radiation therapy.