Radiation therapy is a clinical specialty, dealing with the use of this modality in the treatment of patients with malignant neoplasia. The objective of radiation therapy is to deliver a precisely measured dose of radiation to a defined tumor volume with minimal damage to surrounding healthy tissue, resulting in cure of the tumor and a high quality of life. While training and research are also considered part of radiation oncology services, patient care is the primary focus of this document. In addition to curative efforts, a major component in cancer management is effective palliation or prevention of the symptoms of the disease. This is often neglected when important therapeutic objectives are described, but it remains a major obligation of the physician.
Radiation therapy has outstanding palliative capabilities.
Pain can be alleviated, luminal patency restored, skeletal integrity preserved, and organ function reestablished with minimal morbidity, in a variety of clinical circumstances. The radiation dose can be delivered by directing a beam of ionizing radiation, from an external source, towards the tumor region, or by the use of radioactive sources placed in the tumor region for a prescribed period of time. In external beam radiation therapy, the prescribed radiation dose is delivered in a series of fractions, usually one per weekday for several weeks. A critical step of evaluation of the patient to determine the extent and nature of the tumor. This is important for making the therapeutic decision.