title: Monte Carlo simulation of a whole-body counter using IGOR phantoms.
abstract: Whole-body counting is a technique of choice for assessing the intake of gamma-emitting radionuclides. An appropriate calibration is necessary, which is done either by experimental measurement or by Monte Carlo (MC) calculation. The aim of this work was to validate a MC model for calibrating whole-body counters (WBCs) by comparing the results of computations with measurements performed on an anthropomorphic phantom and to investigate the effect of a change in phantom's position on the WBC counting sensitivity. GEANT MC code was used for the calculations, and an IGOR phantom loaded with several types of radionuclides was used for the experimental measurements. The results show a reasonable agreement between measurements and MC computation. A 1-cm error in phantom positioning changes the activity estimation by >2%. Considering that a 5-cm deviation of the positioning of the phantom may occur in a realistic counting scenario, this implies that the uncertainty of the activity measured by a WBC is ∼10-20%.
authors.affiliation: Institute of Radiation Physics (IRA), Lausanne University Hospital, Lausanne, Switzerland francois.bochud@chuv.ch.
authors.forename: François O
authors.initials: FO
authors.lastname: Bochud
authors.affiliation: Institute of Radiation Physics (IRA), Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Jean-Pascal
authors.initials: JP
authors.lastname: Laedermann
authors.affiliation: Institute of Radiation Physics (IRA), Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Baechler
authors.affiliation: Institute of Radiation Physics (IRA), Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Claude J
authors.initials: CJ
authors.lastname: Bailat
authors.affiliation: Division for Radiation Safety and Security, Paul Scherrer Institute (PSI), Villigen PSI, Switzerland.
authors.forename: Markus
authors.initials: M
authors.lastname: Boschung
authors.affiliation: Institute of Radiation Physics (IRA), Lausanne University Hospital, Lausanne, Switzerland.
authors.forename: Abbas
authors.initials: A
authors.lastname: Aroua
authors.affiliation: Division for Radiation Safety and Security, Paul Scherrer Institute (PSI), Villigen PSI, Switzerland.
authors.forename: Sabine
authors.initials: S
authors.lastname: Mayer
mesh_terms: D002138:Calibration; D003198:Computer Simulation; D006801:Humans; D008954:Models, Biological; D009010:Monte Carlo Method; D019047:Phantoms, Imaging; D011829:Radiation Dosage; D011835:Radiation Protection / Q000379:methods*; D014915:Whole-Body Counting / Q000379:methods*