Types of radiation involved in "Unsealed Source Radiotherapy/Treatment (kind of internal radiotherapy) and how are they produced? Nuclear medicine therapy uses unsealed radioactive sources for the selective delivery of radiation to tumours or target organs. For benign disorders such as thyrotoxicosis and arthritis radionuclide therapy provides an alternative to surgery or medical treatment. In cancer treatment, it often combines the advantage of target selectivity (like brachytherapy or external beam radiotherapy) with that of being systemic, as with chemotherapy, and it may be used as part of a therapeutic strategy with curative intent or for disease control and palliation. Toxicity is generally limited to the haematopoietic tissue and few side-effects are observed. When cure is feasible, the long-term consequences of radionuclide therapy (eg, fertility disorders and leukaemia or other secondary cancers) do compare favourably with the risks associated with and accepted for chemotherapy and radiotherapy. The treatment, which was first started over a hundred years ago has altered a little during the years. By around 1915 the use of radium-226 or radon-222 was used frequently. Two technical innovations began to allay those concerns. In the 1950s, so-called afterloading techniques (remote source handling with increasingly sophisticated robotics) were introduced that dramatically reduced personnel exposure. Around the same time, several new reactor-produced radionuclides with better radiation safety characteristics became available. For example, when ready supplies of cobalt-60 (which has a high specific activity, a 5.27-y halflife, and 1.25-MeV gamma rays) became available 40 years ago, external beam therapy with Co-60 quickly supplanted the 250-kV x-ray tubes then in use. Even today, Co 60 machines remain a vital and dominant treatment option for radiotherapy in developing countries. During the same period, the fission product cesium-137 became available as a safer alternative to 226 Ra for brachytherapy, and it is still in active use for treating gynecological cancers. Whilst this has nothing to do with your question, I add for interest, that gamma rays are used in industry, as are x-rays, for making images of metal objects to discover any faults that may be included during the casting process.
I add a link containing details of the subject of nuclear medicine therapy
http://www.icr.ac.uk/about_
us/annual_research_report/
5872.pdf
Hope this helps
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