Radiation Therapy: General Principles & Techniques

Abstract

Radiation therapy has emerged as an independent medical specialty in the United States only in the past 15 years. Radiation therapists are broadly based oncologic physicians with special training in the technical aspects of radiation therapy, radiation physics, and radiation biology. Radiation therapy is a major form of curative treatment, either alone or in combination with chemotherapy and/or surgery, as well as a major palliative tool in the treatment of malignant disease. The use of ionizing radiation dates to Röntgen’s discovery of x-rays (1895) and to the discovery of natural radioactivity by the Curies and Becquerel. There were numerous aborted attempts to use this new energy to treat patients. In 1913, Coolidge developed an x-ray tube with heated tungsten filament and target in an effective vacuum producing effective x-rays, and thereby providing the foundation for external radiation therapy. The application of radiation therapy by radium containers and interstitial radium for uterine cancer were developed during this period. In 1922, Regaud, Coutard, and Hautant presented evidence that radiation therapy could be applied to cure advanced laryngeal cancer. Coutard and Baclesse developed a specific modality of protracted fractionation (administering the total dose in smaller daily doses extended over longer periods of time) which is today the basis of radiation treatment schedules. Radiation therapists in France, Scandinavia, and England developed techniques for the treatment of patients with cancer of the cervix and defined the guidelines for local radium application.