'Institute of Electrical and Electronics Engineers (IEEE)'
Doi
Abstract
Solid state detectors with nanosecond response timesto incoming radiation are increasingly present at the forefrontof radiotherapy dosimetry research. The fast response time ofmaterials, such as diamond, allow pulse by pulse dosimetry. Thereis a trend in radiotherapy to move towards shorter treatments,using fewer but more intense pulses with varying pulse rates andintensities. This makes the possibility of measuring individualpulses very attractive and would allow intervention during thetreatment and not just afterwards. Here an analogue front endhas been developed and combined with a CVD diamond detectorto provide real time, pulse by pulse beam intensity measure-ments.The front end design is discussed and the experimentalresults obtained using a medical LINAC are presented. Theresults show that pulse by pulse The device is capable of pulseby pulse beam intensity measurements up to pulse rates wellabove 1 kHz. The system performs so well that its variations arenegligible compared to the pulse to pulse intensity variations.The dosimetric performance of our system was compared toa commercially available, integrating diamond detector, themicroDiamond by PTW. The dose and dose-rate linearity of oursystem is comparable with the one of the microDiamond and hasthe additional advantage of being able to measure the depositeddose per pulse
