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| Typical Number in Hospital: 1 | Cost Bands: 8 | References: 3 |
Cobalt-60 produces gamma radiation at 1.17 and 1.33 MeV which is useful in the treatment of deep-seated tumours. Cobalt-60 has a half-life of 5.5 years and thus a sealed unit containing the cobalt will last for a few years. The sealed source contains a number of cobalt discs in a double stainless steel container with a brass window. The source is fitted into a treatment head which contains massive shielding (about 1 ton) and a mechanism for exposing or hiding the source by rotating it away from the collimator, or by rotating the collimator to shield the source.
The gamma-ray beam is directed at the tumour to be treated via a set of collimators and moved during the treatment so that maximum radiation dose is delivered to the point at the centre of the rotation, other parts being irradiated less.
Such devices are found in the radiotherapy department.
Content and Design Copyright 2000 Dr. Malcolm C Brown. See Title Page for more details