Abstract: A quality control accessory (QC accessory) is provided which is adapted for use in linear accelerator quality control or in verification of an arbitrary isocentric radiation treatment plan of a patient or radiation sensitive body. The accessory includes an absorber, a detector and an optional orientation device. The absorber is rotationally symmetric, preferably spherical or hemispherical. The detector is adapted to be fixed in a stationary spatial relationship with respect to the absorber. The optional orientation device is adapted to maintain the two dimensional detector (2d detector) and the absorber in a fixed relative spatial relationship with respect to the beam focus of the linear accelerator, when the gantry is rotated, so that the central axis of the beam is essentially orthogonal to the 2d detector and the phantom axis of symmetry is parallel to or aligned with the central axis of the gantry rotation axis.

Abstract: A quality control accessory (QC accessory) is provided which is adapted for use in linear accelerator quality control or in verification of an arbitrary isocentric radiation treatment plan of a patient or radiation sensitive body. The accessory includes an absorber, a detector and an optional orientation device. The absorber is rotationally symmetric, preferably spherical or hemispherical. The detector is adapted to be fixed in a stationary spatial relationship with respect to the absorber. The optional orientation device is adapted to maintain the two dimensional detector (2d detector) and the absorber in a fixed relative spatial relationship with respect to the beam focus of the linear accelerator, when the gantry is rotated, so that the central axis of the beam is essentially orthogonal to the 2d detector and the phantom axis of symmetry is parallel to or aligned with the central axis of the gantry rotation axis.