Microstrip plastic scintillating detector system for quality assurance in synchrotron microbeam radiotherapy.

Synchrotron microbeam radiotherapy (MRT), which has entered the clinical transfer phase, requires the development of appropriate quality assurance (QA) tools due to very high dose rates and spatial hyperfractionation. A microstrip plastic scintillating detector system with associated modules was proposed in the context of real-time MRT QA. A prototype of such a system with 105 scintillating microstrips was developed and tested under MRT conditions. The signal obtained from each microstrip when irradiated was reproducible, linear with the dose, and independent of both the dose rate and the beam energy. The detector prototype was capable of measuring an entire 52-microbeam field in real time and exhibited outstanding radiation hardness. It could withstand more than 100 kGy absorbed dose, which is at least ten times higher than the doses reported in the literature for plastic scintillators before deterioration. The potential of this detector system in MRT QA was demonstrated in this study.