title: Quality assurance for gamma knife stereotactic radiosurgery.
abstract: OBJECTIVE
  This quality assurance program is designed for stereotactic radiosurgical units, gamma knife, to check and maintain the unit to preclude accidents and comply with current regulations.
  
  
  METHODS
  Over 58 stereotactic radiosurgical units using 201 focused 60Co beams have been installed in the last 7 years and are in use at hospitals throughout the world, with at least 11 additional units being prepared to come on-line in the next year. This system has been in use at the University of Pittsburgh Medical Center (UPMC) for 7 years. A comprehensive quality assurance program has been developed. It includes the physics and dosimetry parameters and safety checks required by regulatory agencies. The program, based on over 7 years of experience in measurements, and used during the treatment of over 1500 patients, is separated into three aspects, namely physics, dosimetry, and safety. The UPMC program hopefully will indicate out-of-tolerance problems. Some quality assurance items are checked on a daily basis prior to patient treatment, while other aspects are checked on a weekly, monthly, and/or annual basis. A complete list of items with their respective time tables and tolerances is provided.
  
  
  RESULTS
  Although experience shows very small margins of error, larger values were chosen to account for variations in equipment and techniques.
  
  
  CONCLUSIONS
  Items included in this quality assurance program should indicate and/or preclude problems encountered in the use of this unit.
authors.affiliation: Department of Radiation Oncology, University of Pittsburgh Medical Center, PA 15213, USA.
authors.forename: A H
authors.initials: AH
authors.lastname: Maitz
authors.forename: A
authors.initials: A
authors.lastname: Wu
authors.forename: L D
authors.initials: LD
authors.lastname: Lunsford
authors.forename: J C
authors.initials: JC
authors.lastname: Flickinger
authors.forename: D
authors.initials: D
authors.lastname: Kondziolka
authors.forename: W D
authors.initials: WD
authors.lastname: Bloomer
mesh_terms: D003037:Cobalt Radioisotopes; D005720:Gamma Rays; D006801:Humans; D011785:Quality Assurance, Health Care; D011786:Quality Control; D016634:Radiosurgery / Q000295:instrumentation* / Q000592:standards*; D012449:Safety; D013238:Stereotaxic Techniques
chemical_list: D003037:Cobalt Radioisotopes