Polymer gels impregnated with gold nanoparticles implemented for measurements of radiation dose enhancement in synchrotron and conventional radiotherapy type beams

Rahman, Wan Nordiana; Wong, Christopher J.; Ackerly, Trevor; Yagi, Naoto; Geso, Moshi

doi:10.1007/s13246-012-0157-x

Cited by 37 publications

(30 citation statements)

References 39 publications

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“…A recent study of polymer gel dosimetry (normoxic polyacrylamide gel and radiochromic gel), show more dose enhancement in the kilovoltage range of energy than in the megavoltage range of energy. 24,25 Comparison of the results for both types of gel is in close agreement, where the variation of DEF obtained for 6 mV is 1.14 (polymer gel) and 1.11 (presage gel) while the DEF obtained at around 80 kV energy is 1.76 (polymer gel) and 1.77 (presage gel). 24,25 In contrast with the unpredictable behavior and variation of biological materials, polymer gel dosimetry provides a more controlled environment for the measurement of the physical dose enhancement effects of gold nanoparticles.…”

supporting

confidence: 58%

Optimal energy for cell radiosensitivity enhancement by gold nanoparticles using synchrotron-based monoenergetic photon beams

Rahman¹,

Corde²,

Yagi³

et al. 2014

IJN

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Gold nanoparticles have been shown to enhance radiation doses delivered to biological targets due to the high absorption coefficient of gold atoms, stemming from their high atomic number (Z) and physical density. These properties significantly increase the likelihood of photoelectric effects and Compton scattering interactions. Gold nanoparticles are a novel radiosensitizing agent that can potentially be used to increase the effectiveness of current radiation therapy techniques and improve the diagnosis and treatment of cancer. However, the optimum radiosensitization effect of gold nanoparticles is strongly dependent on photon energy, which theoretically is predicted to occur in the kilovoltage range of energy. In this research, synchrotron-generated monoenergetic X-rays in the 30–100 keV range were used to investigate the energy dependence of radiosensitization by gold nanoparticles and also to determine the photon energy that produces optimum effects. This investigation was conducted using cells in culture to measure dose enhancement. Bovine aortic endothelial cells with and without gold nanoparticles were irradiated with X-rays at energies of 30, 40, 50, 60, 70, 81, and 100 keV. Trypan blue exclusion assays were performed after irradiation to determine cell viability. Cell radiosensitivity enhancement was indicated by the dose enhancement factor which was found to be maximum at 40 keV with a value of 3.47. The dose enhancement factor obtained at other energy levels followed the same direction as the theoretical calculations based on the ratio of the mass energy absorption coefficients of gold and water. This experimental evidence shows that the radiosensitization effect of gold nanoparticles varies with photon energy as predicted from theoretical calculations. However, prediction based on theoretical assumptions is sometimes difficult due to the complexity of biological systems, so further study at the cellular level is required to fully characterize the effects of gold nanoparticles with ionizing radiation.

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supporting

confidence: 58%

Optimal energy for cell radiosensitivity enhancement by gold nanoparticles using synchrotron-based monoenergetic photon beams

Rahman¹,

Corde²,

Yagi³

et al. 2014

IJN

Self Cite

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“…In photon activation therapy the dose due to secondary particles (Auger electrons) are the most responsible for the biological effect, in some extent similar to the present study in which the secondary electrons are important. Rahman et al [8] used 2 mm slice thickness for magnetic resonance imaging (MRI) analysis of gel samples in an experimental measurement of radiation dose enhancement in 6 MeV electron beam. However, it should be noted that the dose enhancement of nanoparticles in an electron beam irradiation is typically local to them (this happens because of the enhanced production of low energy electrons) and the dose enhancement changes signifi cantly in a sub-mm range.…”

Section: Discussionmentioning

confidence: 99%

“…For photon contamination calculation, F6 tally for photons was scored in the tally cells. The number of electron histories followed was 1.5 × 10 8 . The maximum value of the Monte Carlo type A uncertainty was 5.59% which was related to the cells outside the tumor.…”

Section: Photon Contamination Calculationsmentioning

confidence: 99%

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A Monte Carlo study on dose enhancement and photon contamination production by various nanoparticles in electron mode of a medical linac

Toossi

Ghorbani

Sabet³

et al. 2015

Nukleonika

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The aim of this study is the evaluation of electron dose enhancement and photon contamination production by various nanoparticles in the electron mode of a medical linac. MCNPX Monte Carlo code was used for simulation of Siemens Primus linac as well as a phantom and a tumor loaded with nanoparticles. Electron dose enhancement by Au, Ag, I and Fe2O3 nanoparticles of 7, 18 and 30 mg/ml concentrations for 8, 12 and 14 MeV electrons was calculated. The increase in photon contamination due to the presence of the nanoparticles was evaluated as well. The above effects were evaluated for 500 keV and 10 keV energy cut-offs defined for electrons and photons. For 500 keV energy cut-off, there was no significant electron dose enhancement. However, for 10 keV energy cut-off, a maximum electron dose enhancement factor of 1.08 was observed for 30 mg/ml of gold nanoparticles with 8 MeV electrons. An increase in photon contamination due to nanoparticles was also observed which existed mainly inside the tumor. A maximum photon dose increase factor of 1.07 was observed inside the tumor with Au nanoparticles. Nanoparticles can be used for the enhancement of electron dose in the electron mode of a linac. Lower energy electron beams, and nanoparticles with higher atomic number, can be of greater benefit in this field. Photons originating from nanoparticles will increase the photon dose inside the tumor, and will be an additional advantage of the use of nanoparticles in radiotherapy with electron beams.

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“…Various gold, [10,61,[238][239][240] gold@dielectric hybrids, [10,[241][242][243][244][245][246] and multimodal materials, [96,[246][247][248] have been fabricated and their in vivo functionality as X-ray CT contrast agents for cancer, tissue-specific, and blood-pool imaging. Gold nanomaterials are currently being explored in multiple clinical trials and they constitute a promising next generation candidate for X-ray contrast materials, radiotherapy [249][250][251] and cancer therapy [252].…”

Section: Gold Nanoparticlesmentioning

confidence: 99%

Functionalized nanomaterials: their use as contrast agents in bioimaging: mono- and multimodal approaches

Trequesser¹,

Seznec²,

Delville³

2016

Nano Online

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The successful development of nanomaterials illustrates the considerable interest in the development of new molecular probes for medical diagnosis and imaging. Substantial progress was made in synthesis protocol and characterization of these materials whereas toxicological issues are sometimes incomplete. Nanoparticle-based contrast agents tend to become efficient tools for enhancing medical diagnostics and surgery for a wide range of 2 imaging modalities. Multimodal nanoparticles (NPs) are much more efficient than conventional molecular-scale contrast agents. They provide new abilities for in vivo detection and enhanced targeting efficiencies through longer circulation times, designed clearance pathways, and multiple binding capacities. Properly protected, they can safely be used for the fabrication of various functional systems with targeting properties, reduced toxicity and proper removal from the body. This review mainly describes the advances in the development of mono-to multimodal NPs and their in vitro and in vivo relevant biomedical applications ranging from imaging and tracking to cancer treatment. Besides specific applications for classical imaging, (MRI, PET, CT, US, PAI) are also mentioned less common imaging techniques such as terahertz molecular imaging (THMI) or ion beam analysis (IBA).Perspectives on multimodal theranostic NPs and their potential for clinical advances are also mentioned.

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Polymer gels impregnated with gold nanoparticles implemented for measurements of radiation dose enhancement in synchrotron and conventional radiotherapy type beams

Cited by 37 publications

References 39 publications

Optimal energy for cell radiosensitivity enhancement by gold nanoparticles using synchrotron-based monoenergetic photon beams

Optimal energy for cell radiosensitivity enhancement by gold nanoparticles using synchrotron-based monoenergetic photon beams

A Monte Carlo study on dose enhancement and photon contamination production by various nanoparticles in electron mode of a medical linac

Functionalized nanomaterials: their use as contrast agents in bioimaging: mono- and multimodal approaches

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