title: Use of simple quality assurance procedures in the analysis of beam asymmetries on cobalt-60 treatment units.
abstract: Recently, the mechanical failure of one of the upper collimator mechanical trimmers on a cobalt-60 unit resulted in large beam asymmetries and unacceptable flatness characteristics. This malfunction was not detected using currently accepted schedules for quality assurance tests. The incident suggests that the frequency of routine beam profile constancy checks should be increased to weekly for cobalt-60 units.
authors.affiliation: Department of Radiation Physics, The University of Texas M.D. Anderson Cancer Center, Houston 77030, USA.
authors.forename: M G
authors.initials: MG
authors.lastname: Davis
authors.forename: J L
authors.initials: JL
authors.lastname: Horton
authors.forename: J A
authors.initials: JA
authors.lastname: Bencomo
mesh_terms: D055592:Biophysical Phenomena; D001703:Biophysics; D003037:Cobalt Radioisotopes / Q000627:therapeutic use*; D004868:Equipment Failure; D006801:Humans; D011785:Quality Assurance, Health Care; D011867:Radioisotope Teletherapy / Q000295:instrumentation* / Q000592:standards*; D011874:Radiometry
chemical_list: D003037:Cobalt Radioisotopes