Modernising an accelerator dosemeter system.

The electron linear accelerator is rapidly becoming a dominant radiation therapy treatment unit, and safe and accurate dose monitoring is required for the delivery of safe, accurate treatments. The authors' experience with a 15-year-old accelerator shows that the original dosemeter system failed 19 times. To design an updated dose monitoring system, they used the documents RASMP (1975) and IEC (1977) as guidelines, as well as drawing on their own experience with dosemeters and their problems. Although specifically concerned with the development of a dosemeter system for a Clinac-6 treatment unit, the rationale and specific circuits have broad usefulness.