A beam monitoring and validation system for continuous line scanning in proton therapy.

摘要: Line scanning represents a faster and potentially more flexible form of pencil beam than conventional step-and-shoot irradiations. It seeks to minimize dead times in delivery whilst preserving the possibility modulating dose at any point target volume. Our second generation proton gantry features irradiations line mode, but it still lacks dedicated monitoring validation system that guarantees patient safety throughout irradiation. We report on its design implementation this paper. In scanning, we steer continuously along straight lines while adapting speed and/or current frequently modulate delivered dose. intend prevent errors could be clinically relevant through two-stage system: level 1 monitors position every 10 μs. demonstrate direct readings from ionization chambers nozzle Hall probes scanner magnets provide required information position, respectively. Interlocks will raised when measured signals exceed their predefined tolerance bands. Even case an erroneous delivery, restricts hot cold spots physically fraction to  ±[Formula: see text] (±[Formula: [Formula: biologically). 2-an additional, partly redundant step-we compare integral profile with strip monitor forward-calculated prediction. The comparison is performed between two applications detect amplifying inaccuracies modulation. This can regarded as online quality assurance machine. Both levels use devices functionalities already installed beamline. Hence, presented preserves full compatibility discrete continuous mode single gantry, switching modes during application field.