Characterization of the Theorectical Radiation Dose Enhancement from                     Nanoparticles

Roeske, John C.; Nuñez, Luis; Hoggarth, Mark A.; Labay, Edwardine; Weichselbaum, Ralph R.

doi:10.1177/153303460700600504

Cited by 154 publications

(142 citation statements)

References 37 publications

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“…Among all the situations evaluated, the highest electron dose enhancement obtained was 1.08, which was that of 30 mg/ml Au nanoparticles with 8 MeV electron beams (Table 2). Although this level of dose enhancement is not as high as the levels obtained by brachytherapy photon sources in previous studies [3,6,22], it seems to be a clinically signifi cant value, because it corresponds to an 8% dose enhancement inside the tumor. The fact that the observed dose enhancement for electron beam therapy is lower than brachytherapy depends on the voxelization adopted in these two modalities.…”

Section: Discussioncontrasting

confidence: 54%

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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Section: Discussioncontrasting

confidence: 54%

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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“…A further modelling study compared GNP dose enhancement with a range of X-ray energies, including commonly used brachytherapy radioisotopes, demonstrating, as expected, that high-Z materials at lower photon energies would be predicted to yield the greatest physical enhancement [61]. It was noted that even in the superficial and orthovoltage kilovoltage range, where photoelectric interactions are dominant, significant enhancement would occur only if uniform GNP concentrations were greater than 1 mg ml -1 .…”

Section: Monte Carlo Modelling Studiesmentioning

confidence: 74%

Gold nanoparticles as novel agents for cancer therapy

Jain¹,

Hirst²,

O’Sullivan³

2012

BJR

904

568

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ABSTRACT. Gold nanoparticles are emerging as promising agents for cancer therapy and are being investigated as drug carriers, photothermal agents, contrast agents and radiosensitisers. This review introduces the field of nanotechnology with a focus on recent gold nanoparticle research which has led to early-phase clinical trials. In particular, the pre-clinical evidence for gold nanoparticles as sensitisers with ionising radiation in vitro and in vivo at kilovoltage and megavoltage energies is discussed.

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“…Hainfeld et al further proved that adding gold nanoparticle in radiotherapy is efficacious when treating highly aggressive squamous cell carcinoma using the small animal model [8]. To quantify the dose enhancement due to the heavy atom nanoparticle addition, Roeske et al estimated the dose enhancement factor based on the effective mass energy coefficient and concluded that heavy atom nanoparticle coupled with low-energy photons has the potential of significantly enhancing the delivered dose [9].…”

Section: Introductionmentioning

confidence: 98%

Characteristics of Secondary Electrons from Irradiated Gold Nanoparticle in Radiotherapy

Chow¹

2015

Handbook of Nanoparticles

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The effective range, maximum deflection angle, interaction parameters, and energy deposition of secondary electrons emitted from a gold nanoparticle irradiated by photon beams were calculated by means of Monte Carlo simulations. Moreover, the low-energy electrons (LEEs) with energy range of 3-20 eV, produced when a gold nanoparticle is irradiated by photon beams, were studied. The author's group used the Geant4-based computer code was used to simulate and track secondary electrons from a 100 nm diameter gold nanoparticle irradiated at monoenergetic photon beams of 35, 73.3, 660, and 1,200 keVand from 2, 50, and 100 nm diameter gold nanoparticles irradiated at polyenergetic photon beams of 50 kVp, 250 kVp, 1.25 MV, and 6 MV in water. To investigate the LEEs, secondary electrons emitted from a gold nanoparticle with diameter of 100 nm, interacting with photon beams with energies equal to 35, 73.3, and 600 keV, were simulated using the Geant4 code. The phase spaces of the secondary electrons produced by simulations were then used to simulate the LEEs in water using the NOREC Monte Carlo code. All secondary electrons emitted by the gold nanoparticle and all LEEs produced by each secondary electron were tracked in simulations. The author's group compared the number of secondary electron emitted with and without the gold nanoparticle in water and found that the presence of gold produces more electrons, when irradiated by monoenergetic photon beams with particularly low energy (35 keV). As the photon beam energy was increased from 35 to 1,200 keV, the effective electron range increased from 24.7 to 5,060 mm, but the total number of emitted photoelectric electrons decreased by a factor of 270 per interacting photon. The maximum electron deflection angle relative to the incident beam decreased from 83.1 to 39.2 , and the stopping power of the emitted electron decreased from 1.42 to 0.24 keV/mm. For polyenergetic photon beams with 2, 50, and 100 nm diameter nanoparticles, the author's group found that both irradiations of the 50 and 250 kVp photon beam caused significantly greater deposited energy surrounding the gold nanoparticle (three orders of magnitude) than the MV beams (approximately five times). The author's group also found that a larger portion of deposited energy resided within a larger nanoparticle under the photon irradiation. From the LEE results, the author's group found that the energy distributions of the LEEs from the gold nanoparticle do not vary significantly between different photon beam energies. In addition, the 660 keV photon beam produced more LEEs traveling to a longer range than photon beams of lower energies (35 and 73.3 keV). This higher energy deposition and longer range LEEs produced by the 660 keV photon beam can enhance the cell kill. These simulated results yield important insights concerning the enhancement of tumor cell killing in gold nanoparticle-enhanced radiotherapy. The aim of this chapter is to show that the irradiation of gold nanoparticles at lower monoenergetic and polye...

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Characterization of the Theorectical Radiation Dose Enhancement from Nanoparticles

Cited by 154 publications

References 37 publications

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

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

Gold nanoparticles as novel agents for cancer therapy

Characteristics of Secondary Electrons from Irradiated Gold Nanoparticle in Radiotherapy

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