Radiotherapy:The treatment ofdiseasewith ionizing radiation. Also called radiation therapy.
Inradiotherapy, high-energy rays are often used to damage cancer cells and stop them from growing and dividing. A specialist in the radiation treatment ofcanceris called aradiation oncologist.
Likesurgery,radiation therapyis alocal treatment; it affectscancercells only in the treated area. Radiation can come from a machine (external radiation). It can also come from animplant(a small container of放射性material) placed directly into or near the tumor (internal radiation). Some patients receive both kinds of radiationtherapy.
External radiation therapyis usually given on anoutpatientbasis in ahospitalor clinic, for example, 5 days a week for several weeks. Patients are not radioactive during or after the treatment.
Forinternal radiation therapy,patientusually stays in the hospital for a few days. The radiation implant may be temporary or permanent. Because the level of radiation is highest during the hospital stay, patients may not be able to have visitors or may have visitors only for a short time. Once an implant is removed, there is no radioactivity in the body. The amount of radiation in a permanent implant goes down to a safe level before the patient leaves the hospital.
With radiation therapy, theside effectsdepend on the treatment dose and the part of the body that is treated. The most common side effects are tiredness,skinreactions (such as a rash or redness) in the treated area, and loss of appetite. Radiation therapy can also cause a decrease in the number of whitebloodcells, cells that help protect the body againstinfection. Although the side effects of radiation therapy can be unpleasant, they can usually be treated or controlled and, in most cases, they are not permanent.
