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Author Lin, Y. ♦ Held, K. ♦ Paganetti, H. ♦ Schuemann, J. ♦ McMahon, S.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword APPLIED LIFE SCIENCES ♦ RADIATION PROTECTION AND DOSIMETRY ♦ CARBON IONS ♦ COMPUTERIZED SIMULATION ♦ ENERGY SPECTRA ♦ ION BEAMS ♦ IRRADIATION ♦ MONTE CARLO METHOD ♦ NANOPARTICLES ♦ PHANTOMS ♦ PHASE SPACE ♦ RADIOTHERAPY
Abstract Purpose The aim of this work is to investigate the radiosensitization effect of gold nanoparticles (GNP) in carbon ion irradiation. Nano-scale dosimetric characteristics of GNP interaction with carbon ions as well as the secondary particles generated as a carbon beam traverses the water phantom were studied. Methods Monte Carlo simulations were carried out using TOPAS (Tool for Particle Simulation). First, a water phantom was irradiated by the carbon ion beam and the particle shower spectrum at several depths was recorded in phase spaces. We analyzed the number and energy spectrum of each particle type. Then, the phase spaces obtained from Step 1 were modified to nanometer scale to irradiate a single 50 nm GNP. The secondary electrons that escaped from the GNPs following interactions with each particle type were recorded as phase spaces. The number and energy spectrum of the secondary electrons were studied. The same simulations were repeated replacing the GNPs with water nanoparticles (WNPs) with the same size. The energy absorbed in either GNP or WNP was scored. Results There is a large amount of secondary particles generated through carbon ion beam interaction with the water phantom. Analysis of the secondary electrons generated by the primary particles which escape from the nanoparticle revealed that majority (above 80%) of these electrons were generated by the GNP interaction with Carbon beam itself, making it the biggest contributor to the enhancement. The ratio of the energy absorbed by GNP and WNP is about 8–10 for charged particles and above 3000 for gammas. Conclusion We showed in the study the GNPs may potentially be used to enhance carbon ion therapy, and the main mechanism of enhancement is the interaction with Carbon ion particles itself.
ISSN 00942405
Educational Use Research
Learning Resource Type Article
Publisher Date 2015-06-15
Publisher Place United States
Journal Medical Physics
Volume Number 42
Issue Number 6


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