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For example, the cost of the entire unit used to perform the first cobalt-60 treatment was about $50,000. By way of contrast, it would cost $50,000,000 just to produce enough radium (which had been previously used as a therapy source) to perform the same procedure.
Cobalt therapy is the medical use of gamma rays from the radioisotope cobalt-60 to treat conditions such as cancer.Beginning in the 1950s, cobalt-60 was widely used in external beam radiotherapy (teletherapy) machines, which produced a beam of gamma rays which was directed into the patient's body to kill tumor tissue.
Cobalt-60 beam machine from 1951. Cobalt units use radiation from cobalt-60, which emits two gamma rays at energies of 1.17 and 1.33 MeV, a dichromatic beam with an average energy of 1.25 MeV. The role of the cobalt unit has largely been replaced by the linear accelerator, which can generate higher energy radiation.
The main uses for 60 Co are: As a tracer for cobalt in chemical reactions; Sterilization of medical equipment. [8] Radiation source for medical radiotherapy. [9] Cobalt therapy, using beams of gamma rays from 60 Co teletherapy machines to treat cancer. Radiation source for industrial radiography. [9] Radiation source for leveling devices and ...
a cylinder of radioactive source material (caesium-137 in the Goiânia incident, but usually cobalt-60) The Goiânia accident [ɡojˈjɐniɐ] was a radioactive contamination accident that occurred on September 13, 1987, in Goiânia , Goiás , Brazil, after an unsecured radiotherapy source was stolen from an abandoned hospital site in the city.
A local resident salvaged materials from a discarded radiation therapy machine containing 6,010 pellets of cobalt-60. The transport of the material led to severe contamination of his truck. Remaining pellets in the scrapyard contaminated another 5,000 metric tonnes of steel to an estimated 300 Ci (11 TBq) of activity.
Cobalt machines were relatively cheap, robust and simple to use, although due to its 5.27 year half-life the cobalt had to be replaced about every 5 years. Medical linear particle accelerators, developed since the 1940s, began replacing X-ray and cobalt units in the 1980s and these older therapies are now declining.
The radioactive isotope is used for a variety of medical and industrial purposes including cancer therapy, sterilization of medical equipment, food irradiation and materials testing. It is produced by inserting a 'target' rod rich in non-radioactive cobalt-59 into a reactor core where free neutrons will be captured, turning cobalt-59 into ...