title: Quality assurance study for dosimetry of radiation therapy equipment in Saudi Arabia.
abstract: BACKGROUND
  International standards address the accuracy of dose delivery for radiation therapy machines as well as quality assurance and staffing levels for radiation therapy centers. We performed absolute calibrations of gamma, x-ray and electron radiotherapy beams in all radiation therapy centers in Saudi Arabia. We also assessed quality assurance and staffing levels.
  
  
  METHODS
  Dosimetric measurements were made with a portable dosimetry system, which consisted of a calibrated Farmer ionization chamber and an electrometer, small water phantom, barometer, and thermometer.
  
  
  RESULTS
  Differences between the measured and the expected output (cGy/MU or cGy/min) were found to be in the range of -11% + 5%. About 17% of the radiotherapy beams were not within the acceptable tolerance level (+/-3%). Quality assurance in some radiation therapy centers was poor and staffing levels were inadequate.
  
  
  CONCLUSIONS
  We found poor compliance with internationally accepted tolerance levels for dose calibration of radiotherapy beams at radiation therapy centers in Saudi Arabia. Analysis of medical physics staffing revealed severe discrepancies from those recommended by international guidelines. We recommend that radiation therapy centers be adequately staffed with qualified medical physics personnel and that periodic audit programs be required by a governmental body.
authors.affiliation: Department of Biomedical Physics, Division of Radiation Physics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.
authors.forename: Jazi M
authors.initials: JM
authors.lastname: Al-Mokhlef
authors.forename: Nabaz
authors.initials: N
authors.lastname: Noori