Quality assurance system for a medical linear accelerator

摘要

An image-based quality assurance (IBQA) system is provided for performing quality assurance testing of a medical linear accelerator photon beam. The IBQA system includes an imaging phantom integrated with an automated image analysis system. The imaging phantom comprises a set of fixed and rotatable reference objects which, when radiographed, set the orientation of the phantom, determine magnification factors and measure spatial distortions. The imaging phantom includes a chamber for inserting a radiographic film to record an image of the photon beam. The sampled image is digitized and made available to the automated image analysis system for measuring quality assurance parameters from the sampled image. The measured beam quality parameters are compared with baseline parameter values to determine whether they fall within prescribed specifications. The analysis system includes an integrated database which stores the measured parameters to: establish baseline and tolerance tables for all measured image quality assurance parameters for each accelerator modality and energy; record and retrieve beam quality parameter results for trend analysis and data mining for most AAPM TG-40 beam parameters; select specific protocols for defining the image quality assurance parameters; and generate customized reports responsive to government mandated regulations.