How Does Radiation Therapy Work?

Radiation therapy, or radiotherapy, is the use of various forms of radiation to safely and effectively treat cancer and other diseases. Radiation oncologists may use radiation to cure cancer, to control the growth of the cancer, or to relieve symptoms such as pain.

Radiation therapy works by damaging cells. Normal cells are able to repair themselves, whereas cancer cells cannot. New techniques also allow doctors to better target the radiation to protect healthy cells.

Sometimes radiation therapy is the only treatment a patient needs. At other times, it is only one part of a patient’s treatment. For example, prostate and larynx cancer are often treated with radiotherapy alone, while a woman with breast cancer may be treated with surgery, radiation therapy and chemotherapy.

Radiation may also be used to make your primary treatment more effective. For example, you can be treated with radiation therapy before surgery to help shrink the cancer, or you may be treated with radiation after surgery to destroy small amounts of cancer that may have been left behind.

Sometimes, the overall goal is to slow down the cancer as much as possible. In other cases, the goal is to reduce the symptoms caused by growing tumors and to improve your quality of life. When radiation therapy is administered for this purpose, it is called palliative care or palliation. In this instance, radiation may be used to shrink tumors that are interfering with your quality of life or relieve pain by reducing the size of your tumor.