Radium medical applications

Brachytherapy Sources. The first 252cf sources for radiotherapy research were prepared at SRL about fourteen years ago (4 5). Initially, these sources resembled the classical radium needles familiar in clinical radiotherapy. Eventually, afterloading cells and applicator tubes were supplied to medical evaluators, and all medical sources were improved by the use of californium-palladium cermet wire sheathed in Pt - 10% Ir alloy (6, 7). The most recent designs for medical sources produced in quantity for therapy research are line sources and point sources containing a range of Cf from iess than 1 yg to 200 yg (Figures 9 and 10). 

Radium itself has no commercial applications. Its compounds are used mainly for medical purposes and as a source of radon these absorb some 85 per cent of the world s output 10 per cent is used for rendering dials of instruments and other objects luminous, the remaining 5 per cent being used for scientific and miscellaneous purposes. One mg of radium emits 22 2 X io8 a-particles per min. Its half-life is 1610 years. 

Medical uses of radioactive sources include sterilization, implants using radium, scans using iodine, and therapy using cobalt. X-rays are used in diagnostic medical procedures. In addition to medical facilities, radioactive materials may be found in research laboratories, educational institutions, industrial applications, and hazardous waste sites. 

The medical and scientific communities soon realized that the power of radiation had to be carefully channelled to ensure that its effects were curative rather than harmful. They devised shielding, remote handling devices, and ventilation systems to protect workers from radiation. They also developed international standards to gauge workers exposure to radiation and calibrate doses given to patients. Working with radium came to involve protection as much as application. 

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