Introduction: Radiation therapy is the use of radiation to treat diseases such as cancer and to detect other conditions someone may have. Since the development of radiotherapy, much progress has been made both in the process of using radiation itself, which in turn has increased its effectiveness for medical use, and in the study of other possible uses of radiation. The concepts behind radiotherapy are not overly complicated, but they are still revolutionary ideas that have had a great impact on society and people's well-being. Development of Radiotherapy: The beginnings of radiotherapy were the result of X-rays, first discovered by a German physicist named Wilhelm Roentgen in 1895. During experiments with electricity, he discovered that certain types of energy were able to pass through his body and produce an image of his skeletal structure. Shortly after Roentgen's discovery of how to produce X-rays, their medical potential was explored and used to diagnose health problems. The use of radiation was taken beyond X-rays by Emil Grubbe, who became the first radiation oncologist. Radiation oncology is the study of the therapeutic benefits of radiation. Grubbe earned this title because he was the first to propose the use of X-rays as a treatment for breast cancer, and his experiment was accompanied by immense success. Many people followed in Grubbe's footsteps and became radiation oncologists. Treatment methods have improved in many areas, such as when the dosage should be given, how much should be given per dose, and the ability to target and attack even the deepest cancerous tumors. After these improvements, many radiation oncologists have shifted their attention to more specific treatments and...... half of the article ......ncer Center, 2014. Web. 18 May 2014. Frey, Rebecca J. "Radiotherapy" . The Encyclopedia of Gale Medicine. Ed. Laurie J. Fundukian. 4th ed. Detroit: Gale, 2011. Science in Context. Network. May 19, 2014. Washington, Charles M. and Dennis Leaver, eds. Principles and Practice of Radiotherapy, 3rd ed. St. Louis, MO: Mosby Elsevier, 2010. Meyer, John L., ed. IMRT, IGRT, SBRT: advances in treatment planning and administration of radiotherapy. New York: Karger, 2007. “Radiotherapy.” World of health. Gale, 2000. Science in context. Network. May 19, 2014."Radioactive facilities." World of health. Gale, 2007. Science in context. Network. 19 May 2014."Radioisotopes in medicine." World of physics. Gale, 2007. Science in context. Network. May 19, 2014. Chao, Clifford, et al. Radiotherapy oncology: management decisions. Philadelphia: Lippincott Williams and Wilkins, May 16, 2011. Print.