ASSURANCE OF HIGH-QUALITY LINAC-BASED STEREOTAXIC RADIOSURGERY

Purpose: Stereotactic radiosurgery is generally a single, high-dose ra diation treatment for the brain requiring targeting accuracy on the or der of a millimeter. From the initial implementation of radiosurgery, therefore, quality assurance is an ongoing process of paramount import ance. In this paper, we outline the basic elements of a quality assura nce program for our linear accelerator that has been in use at Washing ton University Medical Center over the past 2 years. Methods and Mater ials: Various devices and procedures have been developed to verify the accuracy and safety of the stereotactic radiosurgery regimen. Specifi cally, we present methods for assessing the attainment of spatially co rrect patient images, the reliability of the computerized treatment pl anning system, achieving physical safety for the patient, as well as t he proper operation of the radiation treatment device. Results: Our pr ocedures have allowed us to assure quality patient treatments and, add itionally, has permitted monitoring our performance for continual impr ovement. For example, a plot of targeting accuracy with the number of patients shows an asymptotic approach to a value within 0.6 mm of that ideally expected. Conclusion: To maintain high-quality patient care, one must review critical aspects of the treatment regimen on a periodi c basis. Providing for the appropriate level of staff training, period ic reviews of procedures and maintenance of forms are also very import ant.