Highlights
- •Monte-Carlo simulation of a prototype electron LINAC.
- •Dose distributions in solid water were measured and compared with simulations.
- •Realistic electron irradiation conditions simulated in voxelised mice CT images.
- •3D dose distributions and dose-volume histograms in lungs of mice were analyzed.
Abstract
Purpose
Measurements and Monte-Carlo simulations were carried out to model the dose distribution
of a prototype electron beam linear accelerator (Kinetron LINAC) to determine the
dose to organs in small animal irradiations experiments. Dose distributions were simulated
using the GATE8.0/Geant4.10.3 Monte-Carlo platform, and measured in air and solid
water phantoms using a commercial scintillating screen detector and new EBT-XD Gafchromic
films.
Methods
The LINAC is able to produce 4.5 MeV electron beams at dose-rates ranging from Gy/min
to thousands of Gy/s, and is used to study the radiobiological effects of very-high
dose-rates that have been shown to protect normal tissues from radiation toxicity.
Numerical simulations and experimental dosimetric characterisation of this electron
accelerator were performed with the Monte-Carlo toolkit and various detectors. Absolute
dose distributions in solid water were measured and compared with simulations. Realistic
electron irradiation conditions were simulated in voxelised mice CT images. 3D dose
distributions and dose-volume histograms in lungs of mice were simulated and analyzed.
Results
Measured and calculated depth-dose profiles for several beam configurations (energy
and dose-rate) were compared. Beam emittance was validated by comparing measured and
calculated beam sizes along the central axis in air: the deviation for all conditions
was less than 1 mm. A good agreement was obtained between experimental dose distributions
and the results obtained with simulations (<2% dose differences for lateral and depth-dose
profiles).
Conclusions
The method presented here, relying on few free parameters, can be adapted to very-high
dose-rate electron irradiation to support the analysis of preclinical research experiments.
Keywords
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Article info
Publication history
Published online: March 27, 2019
Accepted:
March 17,
2019
Received in revised form:
March 12,
2019
Received:
November 28,
2018
Identification
Copyright
© 2019 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.
