Apparatus and method for robotic radiosurgery beam geometry quality assurance

摘要

A method and apparatus for quality assurance of beam geometry of robotic radiosurgery systems. The apparatus comprises two or more radio-opaque markers set at a fixed distance from each other and contained in a housing, which is assembled to a collimator fixture for attachment to the collimator interface of the LINAC of a robotic radiosurgery system. A treatment plan is generated to position the LINAC to a series of pre-defined radiation beam orientations, then a simulation of the treatment is carried out, and radiographic images are taken at each LINAC position. The coordinates of the radio-opaque markers obtained from the images are used to determine beam orientation by calculating their directional cosines, the beam off-axis error and the deviation of the radiation source to iso-center distance (SAD). The imaging system is independently calibrated and the quantitative beam geometric information is used to adjust beam geometry for quality assurance.