Radiation therapy radium

Radon can be isolated from radium by several methods. An aqueous solution of radium salt such as radium bromide is heated, liberating radon. Radioactive bombardment then decomposes water to oxygen and hydrogen. Radon is separated from the gaseous mixture by condensation in tiny tubes placed in liquid air. The tubes then are sealed by melting. A gold or platinum coating is applied to form the radon seeds used in radiation therapy. 

Radiation—the energy particles released by radioactive elements—can be a friend or foe to the human body. As The Radium Girls discovered, radiation can destroy cells and change the DNA in cells in a way that increases the risk of cancer. Yet radiation therapy is also widely used as a treatment for cancer, because carefully targeted radiation can be used to kill cancer cells. 

Sanger, C., High pressure oxygen and radiation therapy. Am. J. Roentgenol. Radium Therapy Nucl. Med. 81, 498-503 (1959). 

Write the nuclear equation for the alpha emission of radium-226, which is used in radiation therapy. 

Bouchard J, Peirce CB Radiation therapy in the management of neoplasms of the central nervous system, with a special note in regard to children twenty years experience, 1939-1958. American Journal of Roentgenology, Radium Therapy and Nuclear Medicine 84 610-628,1960... 

Potential sources for RDWs include hospital radiation therapy (Cobalt-60, Cesium-137), nuclear power fuel rods (Uranium-235, Plutonium), universities and laboratories and radiography and gauging (Cobalt-60, Cesium-13 7, Iridium-192, Radium-226). Unclassified sources reveal that the Iraqis and Russian separatists in Chechnya have already demonstrated practical knowledge of RDWs. The availability of material to make RDWs will inevitably increase in the future as more countries pursue nuclear power (and weapons) programs and radioactive material becomes more available. 

The uranium decay series provides the most important isotopes of elements radium, radon, and polonium, which can be isolated in the processing of uranium minerals. Each ton of uranium is associated with 0.340 g of Ra. Freshly isolated Ra reaches radioactive equilibrium with its decay products to Pb in about two weeks (see Fig. 1.2). Many of these products emit energetic y-rays, which resulted in the use of Ra as a y-source in medical treatment of cancer (radiation therapy). However, the medical importance of radium has diminished greatly since the introduction of other radiation sources, and presently the largest use of radium is as small neutron sources (see Table 12.2). 

Radon has been produced commercially for use in radiation therapy but for the most part has been replaced by radionuclides made in accelerators and nuclear reactors. Radiopharmaceutical companies and a few hospitals pump the radon from a radium source into tubes called "seeds" or "needles" which may be implanted in patients (Cohen 1979). Research laboratories and universities produce radon for experimental studies. 

From experimental beginnings, radiation therapy soon developed into a separate branch of medicine, with its own specialists, practices, and standards. X-rays had to be applied from an external machine, but radium could be introduced right into the patient. This approach, known as brachytherapy, was pioneered early in the century. The radium was put in gold needles that were inserted into cancerous tissue, in tubes that were placed in body cavities, or in moulds applied to the outside of the body. During tumour surgery, doctors permanently implanted gold capsules, or seeds, filled with short-lived radon to help kill residual cancerous cells. 

Low prices may have been bad news for Eldorado, but they were a boon for radiation therapy. Hospitals could afford to buy more radium and employ it more liberally. They supplemented brachytherapy with teletherapy, which exposed tumours to radiation transmitted from several grams of radium mounted in a source external to the patient. The machines developed in the 1930s to hold the radium, aim it at a tumour, and expose it for the appropriate time were called radium bombs. ... 

For both humans and laboratory animals, one cannot currently distinguish between a radiation-induced cancer and a spontaneously occurring cancer (i.e., from an unknown cause). Therefore, statistical methods are used to determine whether radiation exposure is associated with an increase in cancer in a given study population. There have been several epidemiological studies in which definite dose-response relationships have been established for radiation-induced cancers. The best studied populations include atomic bomb survivors, Tinea capitis irradiation patients, ankylosing spondylitis irradiation patients, radium dial painters, radium therapy radium-224 patients, Thorotrast patients, uranium miners, Chernobyl fallout victims, and Mayak plutonium facility workers. 

Macklis RM (1990) Radiation and the era of mild radium therapy. Journal of the American Medical Association 264 614-616. 

Soon after the discoveries of X-rays and radioactivity it was learned that radiation could cause changes in matter. In 1901 P. Curie found that when a radium source was placed on his skin, woimds were produced that were difficult to heal. In 1902 skin cancer was shown to be caused by the radioactivity from radium but S years later it was learnt that radium therapy could be used to heal the disease. Large radiation doses were found to kill fungi and microorganisms and produce mutations in plants. 

The early deaths and other effects of radiation on man led to the initiation of the second International Congress of Radiology to establish the International X-Ray and Radium Protection Committee in 1928. The Committee forced an international cooperation to introduce protective criteria in the use of X-rays and radium therapy. After the beginning of the nuclear age in the 1940s, the increasing interest and extended fields in radiation were restructured and the Committee was renamed the International Commission on Radiological Protection (ICRP), in 1950. Because of the different conditions that apply in various countries, the Commission sets out recommendations but does not intend to provide a regulatory text. 

The use of radioactive isotopes has had a profound effect on the practice of medicine. Radioisotopes were first used in medicine in the treatment of cancer. This treatment is based on the fact that rapidly dividing cells, such as those in cancer, are more adversely affected by radiation from radioactive substances than are cells that divide more slowly. Radium-226 and its decay product radon-222 were nsed for cancer therapy a few years after the discovery of radioactivity. Today gamma radiation from cobalt-60 is more commonly used. 

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