Some observations on x-ray treatment cones

In recent years, considerable attention has been given to the matter of providing the radiotherapist with more reliable high-tension generating equipment and x-ray tubes, more accurate physical measurements of the x-ray output, and more trustworthy evaluations of skin dose and depth dose data. With respect to treatment cones, however, it would appear that some improvement is still necessary. Manufacturers have made available a large variety of cones and applicators which in many cases are being used in conjunction with x-ray equipment without full realization of their individual limitations. In particular, the practice of supplying accessories which attempt to provide for all types of therapy (superficial, deep, and cavity) with the one high-voltage therapy unit has resulted in the production of some treatment cones which do not conform to sound physical principles. This report is based on experience gained during the routine calibration of all types of x-ray equipment in Australia. With many of the point...