Impact of beam quality on megavoltage radiotherapy treatment techniques utilizing gold nanoparticles for dose enhancement

2013 ◽  
Vol 58 (3) ◽  
pp. 451-464 ◽  
Author(s):  
Panagiotis Tsiamas ◽  
Bo Liu ◽  
Fulya Cifter ◽  
Wilfred F Ngwa ◽  
Ross I Berbeco ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Beam Quality ◽  
Dose Enhancement ◽  
Treatment Techniques ◽  
Radiotherapy Treatment

The effects of gold nanoparticles concentrations and beam quality/LET on dose enhancement when irradiated with X-rays and protons using alanine/EPR dosimetry

2017 ◽  
Vol 106 ◽  
pp. 352-356 ◽  
Author(s):  
Clare L. Smith ◽  
Stephen P. Best ◽  
Frank Gagliardi ◽  
Takahiro Tominaga ◽  
Moshi Geso
Keyword(s):  
Gold Nanoparticles ◽  
Beam Quality ◽  
X Rays ◽  
Dose Enhancement ◽  
Epr Dosimetry

scholarly journals Monte Carlo characterization of the gold nanoparticles dose enhancement and estimation of the physical interactions weight in dose enhancement mechanism

2020 ◽  
Vol 26 (4) ◽  
pp. 217-223
Author(s):  
Mohammad Mohammadzadeh ◽  
Hosein Ghiasi
Keyword(s):  
Gold Nanoparticles ◽  
Monte Carlo ◽  
Beam Quality ◽  
Simulation Method ◽  
Photoelectric Effect ◽  
Dose Enhancement ◽  
Heavy Atoms ◽  
Physical Interactions ◽  
The Subject

AbstractRadiosensitization of the cancer cells by the heavy atoms of nanoparticles was the subject of some studies. But, the physical characterization to determine the weight of all interactions hasn’t been made numerically. The aim of this study was to calculate and compare the dose enhancement (DE) for different energies. The Monte Carlo simulation method was used in the current study. The influence of gold nanoparticles (GNP) size, beam quality, the GNP concentration, and dose inhomogeneity on the radiosensitization by DE was studied. A 35% increase in the photoelectric effect was observed while energy decreased from 18 MV to 300 kV. In the microscopic study which DE calculated in 30 µm from a single GNP, a 79% decreasing in DE within the first 1µm was seen and it declined to 2% in 30 µm from the GNP center. The effect was observed at small distances only. Our study revealed that the dose inhomogeneity around a nanoparticle is the main and very strong effect of DE on a macroscopic scale. In the location which 35% DE occurs most malignant cells survival will be effectively reduced. Our research indicates the need for further research.

Dosimetry and Radioenhancement Comparison of Gold Nanoparticles in Kilovoltage and Megavoltage Radiotherapy using MAGAT Polymer Gel Dosimeter

2019 ◽  
Vol 9 (2Apr) ◽  
Author(s):  
S Farahani ◽  
N Riyahi Alam ◽  
S Haghgoo ◽  
M Khoobi ◽  
Gh Geraily ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
3D Visualization ◽  
Energy Levels ◽  
Polymer Gel ◽  
External Radiotherapy ◽  
Dose Enhancement ◽  
Internal Radiotherapy ◽  
Boost Radiotherapy

Background: Numerous unique characteristics of the nanosized gold, including high atomic number, low toxicity, and high biocompatibility make it one of the most appropriate nanostructures to boost radiotherapy efficacy. Many in-vivo and in-vitro investigations have indicated that gold nanoparticles (AuNPs) can significantly increase tumor injuries in low kilovoltage radiotherapy. While deep-lying tumors require much higher energy levels with greater penetration power, and investigations carried out in megavoltage energy range show contradictory results.Objective: In this study, we quantitatively assess and compare dose enhancement factors (DEFs) obtained through AuNPs under radiation of Cobalt-60 source (1.25MeV) versus Iridium-192 source (0.380 KeV) using MAGAT gel dosimeter.Material and Methods: MAGAT polymer gel in both pure and combined with 0.2 mM AuNPs was synthesized. In order to quantify the effect of energy on DEF, irradiation was carried out by Co-60 external radiotherapy and Ir-192 internal radiotherapy. Finally, readings of irradiated and non-irradiated gels were performed by MR imaging.Result: The radiation-induced R2 (1/T2) changes of the gel tubes doped with AuNPs compared to control samples, upon irradiation of beams released by Ir-192 source showed a significant dose enhancement (15.31% ±0.30) relative to the Co-60 external radiotherapy (5.85% ±0.14).Conclusion: This preliminary study suggests the feasibility of using AuNPs in radiation therapy (RT), especially in low-energy sources of brachytherapy. In addition, MAGAT polymer gel, as a powerful dosimeter, could be used for 3D visualization of radiation dose distribution of AuNPs in radiotherapy.

scholarly journals The effect of flattening filter free delivery on endothelial dose enhancement with gold nanoparticles

2013 ◽  
Vol 40 (3) ◽  
pp. 031706 ◽  
Author(s):  
Alexandre Detappe ◽  
Panagiotis Tsiamas ◽  
Wilfred Ngwa ◽  
Piotr Zygmanski ◽  
Mike Makrigiorgos ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Dose Enhancement ◽  
Flattening Filter Free ◽  
Flattening Filter

scholarly journals Different distributions of gold nanoparticles on the tumor and calculation of dose enhancement factor by Monte Carlo simulation

2019 ◽  
Vol 5 (4) ◽  
pp. 361-371 ◽  
Author(s):  
Sajad Keshavarz ◽  
Dariush Sardari
Keyword(s):  
Gold Nanoparticles ◽  
Uniform Distribution ◽  
Enhancement Factor ◽  
Radiation Energy ◽  
Distribution Model ◽  
Distribution Models ◽  
Dose Enhancement ◽  
X Ray ◽  
Nanoparticle Distribution ◽  
Nanoparticle Sizes

Gold nanoparticles can be used to increase the dose of the tumor due to its high atomic number as well as being free from apparent toxicity. The aim of this study is to evaluate the effect of distribution of gold nanoparticles models, as well as changes in nanoparticle sizes and spectrum of radiation energy along with the effects of nanoparticle penetration into surrounding tissues in dose enhancement factor DEF. Three mathematical models were considered for distribution of gold nanoparticles in the tumor, such as 1-uniform, 2- non-uniform distribution with no penetration margin and 3- non-uniform distribution with penetration margin of 2.7 mm of gold nanoparticles. For this purpose, a cube-shaped water phantom of 50 cm size in each side and a cube with 1 cm side placed at depth of 2 cm below the upper surface of the cubic phantom as the tumor was defined, and then 3 models of nanoparticle distribution were modeled. MCNPX code was used to simulate 3 distribution models. DEF was evaluated for sizes of 20, 25, 30, 50, 70, 90 and 100 nm of gold nanoparticles, and 50, 95, 250 keV and 4 MeV photon energies. In uniform distribution model the maximum DEF was observed at 100 nm and 50 keV being equal to 2.90, in non-uniform distribution with no penetration margin, the maximum DEF was measured at 100 nm and 50 keV being 1.69, and in non-uniform distribution with penetration margin of 2.7 mm, the maximum DEF was measured at 100 nm and 50 keV as 1.38, and the results have been showed that the dose was increased by injecting nanoparticles into the tumor. It is concluded that the highest DEF could be achieved in low energy photons and larger sizes of nanoparticles. Non-uniform distribution of gold nanoparticles can increase the dose and also decrease the DEF in comparison with the uniform distribution. The non-uniform distribution of nanoparticles with penetration margin showed a lower DEF than the non-uniform distribution without any margin and uniform distribution. Meanwhile, utilization of the real X-ray spectrum brought about a smaller DEF in comparison to mono-energetic X-ray photons.

An investigation of the effect of gold nanoparticles with different concentrations on increasing absorbed dose: an empirical and simulation study

2018 ◽  
Vol 18 (02) ◽  
pp. 191-197
Author(s):  
Masoumeh Hoseinnezhad ◽  
Mohammad Mahdavi ◽  
Seyyed R. M. Mahdavi ◽  
Mobarake Mahdavizade
Keyword(s):  
Monte Carlo Simulation ◽  
Gold Nanoparticles ◽  
Monte Carlo ◽  
Absorbed Dose ◽  
Simulation Method ◽  
Dose Enhancement ◽  
Depth Dose ◽  
Optical Ct ◽  
Ct System ◽  
Monte Carlo Simulation Model

AbstractPurposeThe purpose of this study was to determine the dose enhancement factor (DEF) of gold nanoparticles in a dosimeter gel and construct percentage depth dose curves, using the Optical CT system and the Monte Carlo simulation model, to determine the effect of increasing the dose caused by increasing the concentration of gold nanoparticles at depths in the gel.Materials and methodsThe Magic-f Gel was made based on the relevant protocol in the physics lab. To determine the amount of the increase in the absorbed dose, the gold nanoparticles were added to the gel and irradiated. An increase in the dose after adding nanoparticles to the gel vials was estimated both with the Optical CT system and by the Monte Carlo simulation method.ResultsDose enhancement curves for doses of 2, 4 and 6 Gy were prepared for gel vials without adding nanoparticles, and nanoparticle gels at concentrations 0·17, 3 and 6 mM. Also, the DEF was estimated. For the 0·17 mM molar gel, the DEF for 2, 4 and 6 Gy was 0·7, 0·743 and 0·801, respectively. For the 3 mM gel, it was 1·98, 2·5 and 2·2, and for the 6 mM gel, it was 37·4, 4·24 and 4·71, respectively.ConclusionThe enhancement of the dose after adding gold nanoparticles was confirmed both by experimental data and by simulation data.

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