USE OF A MICRO-IONIZATION CHAMBER AND AN ANTHROPOMORPHIC HEAD PHANTOMIN A QUALITY ASSURANCE PROGRAM FOR STEREOTAXIC RADIOSURGERY

Quality assurance methods used in association with radiosurgery must i nclude all aspects of the radiosurgery process: visualization and loca lization of the target, treatment and dose planning and dose delivery. Presented here is a quality assurance method that utilizes an anthrom orphic head phantom and a micro-ionization chamber to demonstrate prec ise target localization and accurate dose delivery. This micro-ionizat ion chamber method offers an immediate readout which is both accurate and reproducible. Additionally, this method allows unlimited repetitio n of the dose measurement process without repeated radiographic locali zation studies as is necessary with the conventional methods of TLD, f ilm, and Fricke gels. The method and techniques presented can be used in the acceptance testing and routine quality assurance of both linac- based and Gamma Knife radiosurgery units. (C) 1996 American Associatio n of Physicists in Medicine.