Abstract
Purpose
Monte Carlo study of radiation transmission around areas surrounding a PET room.
Methods
An extended population of patients administered with 18F-FDG for PET-CT investigations was studied, collecting air kerma rate and gamma ray
spectra measurements at a reference distance. An MC model of the diagnostic room was
developed, including the scanner and walls with variable material and thickness. MC
simulations were carried out with the widely used code GEANT4.
Results
The model was validated by comparing simulated radiation dose values and gamma ray
spectra produced by a volumetric source with experimental measurements; ambient doses
in the surrounding areas were assessed for different combinations of wall materials
and shielding and compared with analytical calculations, based on the AAPM Report
108.
In the range 1.5–3.0 times of the product between the linear attenuation coefficient
and thickness of an absorber (μ x), it was observed that the effectiveness of different
combinations of shielding is roughly equivalent. An extensive tabulation of results
is given in the text.
Conclusions
The validation tests performed showed a satisfactory agreement between the simulated
and expected results. The simulated dose rates incident on, and transmitted by the
walls in our model of PET scanner room, are generally in good agreement with analytical
estimates performed using the AAPM Publication No. 108 method. This provides an independent
confirmation of AAPM's approach. Even in this specific field of application, GEANT4
proved to be a relevant and accurate tool for dosimetry estimates, shielding evaluation
and for general radiation protection use.
Keywords
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Article info
Publication history
Published online: January 21, 2014
Accepted:
December 20,
2013
Received in revised form:
December 19,
2013
Received:
May 8,
2013
Identification
Copyright
© 2014 Associazione Italiana di Fisica Medica. Published by Elsevier Inc. All rights reserved.
