MO-FG-BRA-03: A Monte-Carlo Study of Cellular Dosimetry of Radioactive Gold-Palladium Nanoparticles

Journal Article · Mon Jun 15 00:00:00 EDT 2015 · Medical Physics

DOI:https://doi.org/10.1118/1.4925407· OSTI ID:22562900

Ma, Y ^[1]; Michaud, F ^[2]; Fortin, M ^[3]; Beaulieu, L ^[4]

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1. CHU de Quebec, Quebec, QC (Canada)
2. Rutherford Physics Building, Montreal, Quebec (Canada)
3. Hopital Saint-Francois -d’Assise, Quebec, Quebec (Canada)
4. Centre Hospitalier Univ de Quebec, Quebec, QC (Canada)

Purpose: Radioactive gold-palladium nanoparticles ({sup 103}Pd:Pd@Au NPs) are being developed for prostate cancer brachytherapy. Photons emitted by the radioisotope palladium (photon energy: 20.1 and 23.0 keV), interacting with gold-coating of NPs, lead to enhanced energy distribution in nucleus. Here, a simple cellular model was studied using detailed track-structure method. Methods: Geant4-DNA was used with auger electrons enabled. Biological cell was modeled as a sphere of radius r=5 µm that were immersed in a fluid containing large number of NPs at different concentrations (S=1, 2.15, 5.1, 17.2 mg-Au/g-H2O). Nucleus was modeled as a concentric sphere (r=3µm). Thickness of gold-coating on {sup 103}Pd core was 15nm, 20nm and 25nm, respectively. A scenario of NP diffusion was investigated, where S=5.1 mg-Au/g-H2O outside cell and S=1 mg-Au/g-H2O in cytoplasm. 10{sup 10} {sup 103}Pd decays were simulated for each combination of NP concentration and gold-coating. Results: A uniform increase in energy deposition (Edep) is observed in cell nucleus and the energy enhancement ratio (EER) is 1.16, 1.22 and 1.3 for 15nm, 20nm and 25nm of gold -coatings, respectively. Edep at the center of nucleus is increased by a factor of 1.47, 2.51 and 5.54 when the NP concentration in the cytoplasm increases from 1 mg-Au/g-H2O to 2.15, 5.10 and 17.2 mg-Au/g-H2O, respectively. When NPs diffuse into cytoplasm, the mean value of Edep in nucleus increases from 0.42 to 1.13 MeV per 10{sup 9} decays (GBq-Second) of {sup 103}Pd and the maximum value increases from 0.54 to 2.5 MeV per GBq-Second. Conclusion: These results suggest that {sup 103}Pd:Pd@Au NPs constitute a promising nanotherapeutic agent. Ongoing studies use transmission electron microscopy (TEM) images of prostate cancer.

• OSTI ID: 22562900
• Journal Information: Medical Physics, Vol. 42, Issue 6; Other Information: (c) 2015 American Association of Physicists in Medicine; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-2405
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
61 RADIATION PROTECTION AND DOSIMETRY
ABUNDANCE
BRACHYTHERAPY
CELL NUCLEI
CONCENTRATION RATIO
CYTOPLASM
DNA
DOSIMETRY
ENERGY ABSORPTION
ENERGY LOSSES
ENERGY SPECTRA
GOLD
MONTE CARLO METHOD
NANOPARTICLES
NEOPLASMS
PALLADIUM
PALLADIUM 103
PARTICLE TRACKS
PROSTATE
TRANSMISSION ELECTRON MICROSCOPY