Patent ID: 8242458

Claim:
A system for irradiating a patient with a particle beam of charged particles, comprising: a raster scanning irradiation unit, which comprises a particle accelerator, a beam guide unit, and a 3D scanning system, wherein the 3D scanning system comprises an energy variation unit for setting an energy of the particle beam and thus a penetration depth of the particle beam into the patient in a beam direction and a deflecting unit with several deflecting magnets for a two-dimensional deflection of the particle beam between individual raster points in each of several layers of predefined penetration depth in the patient, the layers being defined by the energy variation unit and being situated transversely to the beam direction; a therapy planning system for generating therapy planning data, which comprise an energy and number of charged particles for each raster point in each layer as derived from a desired dose distribution; a therapy control system, which converts the therapy planning data generated by the therapy planning system into irradiation data and irradiation commands for the particle accelerator, the beam guide unit, and the 3D scanning system; and a plurality of safety devices for ensuring that the therapy planning data have been converted correctly and for verifying the functionality of the system; wherein the plurality of safety devices comprises an evaluation unit, which checks the irradiation data and irradiation commands supplied by the therapy control system to the 3D scanning system to verify a therapy-specific plausibility of the irradiation data and irradiation commands; wherein the evaluation unit checks a sequence and arrangement of the raster points to be hit during a scanning process for each layer by deriving x values and y values for all raster points of one layer of predetermined penetration depth to be hit during a scanning process, determining from them a progression from one raster point to another in a sequence of administration within the two-dimensional arrangement of the raster points, and then checking the progression against predetermined criteria, wherein the evaluation unit derives the x values and the y values for all raster points from values of magnet currents of the deflecting magnets of the deflecting unit, said values of magnet currents being included in the irradiation data and irradiation commands supplied by the therapy control system to the 3D scanning system.