OUTPUT MEASUREMENTS AND THE USE OF ISODOSE CHARTS

The provision of more accurate dosage information and treatment plans is of the greatest value to radiotherapy provided that the treatment they represent can be applied with equal accuracy to the patient. The provision of the basic dosage data that are required for clinical work; to the consideration of how this information is to be used; and to deciding what other information may be needed or what other measurements may be required on an X-ray set or teletherapy unit being used for radiotherapy. The data can be little affected by the detailed design of the beam producing equipment so that information obtained with one X-ray tube can, quite reasonably, be applied to another working under similar conditions. This chapter describes two main methods called the output with backscatter and the output in air methods.