Absorbed energy monitoring during hadrontherapy via prompt gamma detection

An independent monitoring system aiming for the detection of deviations from the prescribed treatment in hadrontherapy is presented. The system is based on prompt gamma-ray detection via scintillation detectors and the use of time-of-flight information. Test measurements at cyclotrons show the influence of degraders used in passive beam delivery systems. A dedicated data acquisition card has been developed which is suitable to provide timing and energy information from scintillation detectors at counting rates compatible with clinical beam intensities.