A Monte Carlo Study on Dose Enhancement by Homogeneous and Inhomogeneous Distributions of Gold Nanoparticles in Radiotherapy with Low Energy X-rays
Background: To enhance the dose to tumor, the use of high atomic number elements has been proposed. Objective: The aim of this study is to investigate the effect of gold nanoparticle distribution on dose enhancement in tumor when the tumor is irradiated by typical monoenergetic X-ray beams by c...
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| Format: | Article |
| Language: | English |
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Shiraz University of Medical Sciences
2018-03-01
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| Series: | Journal of Biomedical Physics and Engineering |
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| Online Access: | http://jbpe.ir/Journal_OJS/JBPE/index.php/jbpe/article/view/413/409 |
| _version_ | 1818559090230558720 |
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| author | M Zabihzadeh T Moshirian M Ghorbani C Knaup M A Behrooz |
| author_facet | M Zabihzadeh T Moshirian M Ghorbani C Knaup M A Behrooz |
| author_sort | M Zabihzadeh |
| collection | DOAJ |
| description | Background: To enhance the dose to tumor, the use of high atomic number elements has been proposed.
Objective: The aim of this study is to investigate the effect of gold nanoparticle distribution on dose enhancement in tumor when the tumor is irradiated by typical monoenergetic X-ray beams by considering homogeneous and inhomogeneous distributions of gold nanoparticles (GNPs) in the tumor.
Methods: MCNP-4C Monte Carlo code was utilized for the simulation of a source, a phantom containing tumor and gold nanoparticles with concentrations of 10, 30 and 70 mg Au/g tumor. A 15 cm×15 cm×15 cm cubic water phantom was irradiated with a small planar source with four monoenergetic X-ray beams of 35, 55, 75 and 95 keV energy. Furthermore, tumor depths of 2.5 cm, 4.5 cm and 6.5 cm with homogeneous and inhomogeneous distributions of nanoparticles were studied. Each concentration, photon energy, tumor depth and type of distribution was evaluated in a separate simulation.
Results: Results have shown that dose enhancement factor (DEF) in tumor increases approximately linearly with the concentration of gold nanoparticles. While DEF has fluctuations with photon energy, 55 keV photons have the highest DEF values compared to other energies. While DEF has relatively the same values with tumor located at various depths, inhomogeneous distribution of GNP has shown different results compared with the homogeneous model. Dose enhancement can be expected with relatively deep seated tumors in radiotherapy with low energy X-rays. Inhomogeneous model is recommended for the purpose of dose enhancement study because it mimics the real distribution of GNPs in tumor. |
| first_indexed | 2024-12-14T00:20:49Z |
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| issn | 2251-7200 2251-7200 |
| language | English |
| last_indexed | 2024-12-14T00:20:49Z |
| publishDate | 2018-03-01 |
| publisher | Shiraz University of Medical Sciences |
| record_format | Article |
| series | Journal of Biomedical Physics and Engineering |
| spelling | doaj.art-eca0fee0e49047188ded092484ff1ae12022-12-21T23:25:13ZengShiraz University of Medical SciencesJournal of Biomedical Physics and Engineering2251-72002251-72002018-03-0181132810.22086/jbpe.v0i0.413A Monte Carlo Study on Dose Enhancement by Homogeneous and Inhomogeneous Distributions of Gold Nanoparticles in Radiotherapy with Low Energy X-raysM Zabihzadeh0 T Moshirian1M Ghorbani2C Knaup3M A Behrooz4Department of Medical Physics, Faculty of Medicine, Ahvaz Jundishapur University of Medical Department of Medical Physics, Faculty of Medicine, Ahvaz Jundishapur University of Medical Biomedical Engineering and Medical Physics Department, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, IranComprehensive Cancer Centers of Nevada, Las Vegas, Nevada, USADepartment of Medical Physics, Faculty of Medicine, Ahvaz Jundishapur University of Medical Background: To enhance the dose to tumor, the use of high atomic number elements has been proposed. Objective: The aim of this study is to investigate the effect of gold nanoparticle distribution on dose enhancement in tumor when the tumor is irradiated by typical monoenergetic X-ray beams by considering homogeneous and inhomogeneous distributions of gold nanoparticles (GNPs) in the tumor. Methods: MCNP-4C Monte Carlo code was utilized for the simulation of a source, a phantom containing tumor and gold nanoparticles with concentrations of 10, 30 and 70 mg Au/g tumor. A 15 cm×15 cm×15 cm cubic water phantom was irradiated with a small planar source with four monoenergetic X-ray beams of 35, 55, 75 and 95 keV energy. Furthermore, tumor depths of 2.5 cm, 4.5 cm and 6.5 cm with homogeneous and inhomogeneous distributions of nanoparticles were studied. Each concentration, photon energy, tumor depth and type of distribution was evaluated in a separate simulation. Results: Results have shown that dose enhancement factor (DEF) in tumor increases approximately linearly with the concentration of gold nanoparticles. While DEF has fluctuations with photon energy, 55 keV photons have the highest DEF values compared to other energies. While DEF has relatively the same values with tumor located at various depths, inhomogeneous distribution of GNP has shown different results compared with the homogeneous model. Dose enhancement can be expected with relatively deep seated tumors in radiotherapy with low energy X-rays. Inhomogeneous model is recommended for the purpose of dose enhancement study because it mimics the real distribution of GNPs in tumor.http://jbpe.ir/Journal_OJS/JBPE/index.php/jbpe/article/view/413/409Gold NanoparticleDose EnhancementHomogeneous DistributionInhomogeneous Distribution |
| spellingShingle | M Zabihzadeh T Moshirian M Ghorbani C Knaup M A Behrooz A Monte Carlo Study on Dose Enhancement by Homogeneous and Inhomogeneous Distributions of Gold Nanoparticles in Radiotherapy with Low Energy X-rays Journal of Biomedical Physics and Engineering Gold Nanoparticle Dose Enhancement Homogeneous Distribution Inhomogeneous Distribution |
| title | A Monte Carlo Study on Dose Enhancement by Homogeneous and Inhomogeneous Distributions of Gold Nanoparticles in Radiotherapy with Low Energy X-rays |
| title_full | A Monte Carlo Study on Dose Enhancement by Homogeneous and Inhomogeneous Distributions of Gold Nanoparticles in Radiotherapy with Low Energy X-rays |
| title_fullStr | A Monte Carlo Study on Dose Enhancement by Homogeneous and Inhomogeneous Distributions of Gold Nanoparticles in Radiotherapy with Low Energy X-rays |
| title_full_unstemmed | A Monte Carlo Study on Dose Enhancement by Homogeneous and Inhomogeneous Distributions of Gold Nanoparticles in Radiotherapy with Low Energy X-rays |
| title_short | A Monte Carlo Study on Dose Enhancement by Homogeneous and Inhomogeneous Distributions of Gold Nanoparticles in Radiotherapy with Low Energy X-rays |
| title_sort | monte carlo study on dose enhancement by homogeneous and inhomogeneous distributions of gold nanoparticles in radiotherapy with low energy x rays |
| topic | Gold Nanoparticle Dose Enhancement Homogeneous Distribution Inhomogeneous Distribution |
| url | http://jbpe.ir/Journal_OJS/JBPE/index.php/jbpe/article/view/413/409 |
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