Use of Nanoparticles in Brachytherapy – An Alternative for Enhancing Doses in Cancer Treatment

Gual, Maritza Rodríguez; Cardona, Caridad M. Alvarez; González, Landy Y. Castro; García, Jesús Rosales

doi:10.1007/978-3-642-03474-9_153

Cited by 5 publications

(3 citation statements)

References 5 publications

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“…The source design, dimensions, and materials of flexi 60 Co HDR source was provided by the manufacturer, and shown schematically in Figure 1B. It is composed of a central cylindrical active core made of metallic 60 Co, with a density of 8.9 g/cc, 3.5 mm in length and 0.5 mm in diameter [10,14,17]. The active core of flexisource 60 Co radionuclide source is covered by a cylindrical 316L stainless steel of elemental composition by weight Fig.…”

Section: Source Descriptionmentioning

confidence: 99%

Dosimetric comparison between microSelectron iridium-192 and flexi cobalt-60 sources in high-dose-rate brachytherapy using Geant4 Monte Carlo code

Gebremariam¹,

Geraily²,

Jassim³

et al. 2023

jcb

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Purpose: Manufacturing of miniaturized high activity sources have been made a market preference in modern brachytherapy. Smaller dimensions of the sources are flexible for smaller diameter of the applicators, and it is also suitable for interstitial implants. Presently, cobalt-60 ( 60 Co) sources have been commercialized as an alternative to 192 Ir sources for high-dose-rate (HDR) brachytherapy, since 60 Co source have an advantage of longer half-life comparing with 192 Ir source. One of them is the HDR 60 Co Flexisource manufactured by Elekta. The purpose of this study was to compare the TG-43 dosimetric parameters of HDR flexi 60 Co and HDR microSelectron 192 Ir sources.Material and methods: Monte Carlo simulation code of Geant4 (v.11.0) was applied. Following the recommendations of AAPM TG-43 formalism report, Monte Carlo code of HDR flexi 60 Co and HDR microSelectron 192 Ir was validated by calculating radial dose function, anisotropy function, and dose-rate constants in a water phantom. Finally, results of both radionuclide sources were compared.Results: The calculated dose-rate constants per unit air-kerma strength in water medium were 1.108 cGy h -1 U -1 for HDR microSelectron 192 Ir, and 1.097 cGy h -1 U -1 for HDR flexi 60 Co source, with the percentage uncertainty of 1.1% and 0.2%, respectively. The values of radial dose function for distances above 22 cm for HDR flexi 60 Co source were higher than that of the other source. The anisotropic values sharply increased to the longitudinal sides of HDR flexi 60 Co source, and the rise was comparatively sharper to that of the other source.Conclusions: The primary photons from the lower-energy HDR microSelectron 192 Ir source have a limited range and are partially attenuated when considering the results of radial and anisotropic dose distribution functions. This implies that a HDR flexi 60 Co radionuclide could be used to treat tumors beyond the source compared with a HDR microSelectron 192 Ir source, despite the fact that 192 Ir has a lower exit dose than HDR flexi 60 Co radionuclide source.

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Section: Source Descriptionmentioning

confidence: 99%

Dosimetric comparison between microSelectron iridium-192 and flexi cobalt-60 sources in high-dose-rate brachytherapy using Geant4 Monte Carlo code

Gebremariam¹,

Geraily²,

Jassim³

et al. 2023

jcb

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“…This interaction increases the production of copious numbers of secondary particles, such as Auger electrons, which contribute greatly to dose enhancement and radiation damage effects on tumor cell DNA (Gholami et al 2019). Many previous studies have addressed dose enhancement to a tumor with GNPs using Ir-192 brachytherapy (Cho and Krishnan 2007, Gual et al 2009, Khosravi et al 2015, Retif et al 2015, Zabihzadeh and Arefian 2015, Farahani et al 2019. Monte Carlo methods, in vitro experiments (Chithrani et al 2010, Jain et al 2011, and in vivo studies (Hainfeld et al 2004, 2013, Chang et al 2008, Kim et al 2012, Zhang et al 2012, Joh et al 2013, Bobyk et al 2013, Chen et al 2015 have been implemented to better understand the dose enhancing effect of these high-Z materials.…”

Section: Introductionmentioning

confidence: 99%

“…The authors determined that the larger the GNP radius, the larger the dose enhancement was. In a study published by Gual et al (2009), the Monte Carlo transport code MCNPX was utilized to estimate dose enhancement to tumor cells during brachytherapy. A 192 Ir source was modeled in a uterus phantom proposed by Eckerman and Cristy (Cristy and Eckerman 1987).…”

Section: Introductionmentioning

confidence: 99%

A detailed Monte Carlo evaluation of ¹⁹²Ir dose enhancement for gold nanoparticles and comparison with experimentally measured dose enhancements

et al. 2020

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Gold nanoparticles (GNPs) have been studied extensively as promising radiation dose enhancing agents. In the current study, the dose enhancement effect of GNPs for Ir-192 HDR brachytherapy is studied using Monte Carlo N-Particle code, version 6.2 (MCNP6.2) and compared with experimental results obtained using Burlin cavity theory formalism. The Ir-192 source is verified using TG-43 parameters and dose enhancement factors (DEFs) from GNPs are simulated for three different mass percentages of gold in the GNP solution. These results are compared to DEFs previously reported experimentally by our group (Bassiri et al Med. Phys.) for a GNP-containing volume in an apparatus designed in-house to measure dose enhancement with GNPs for high dose rate (HDR) Ir-192 brachytherapy. An HDR Ir-192 Microselectron v2 r HDR brachytherapy source was modeled using MCNP6.2 using the TG-43 formalism in water. Anisotropy and radial dose function were verified against known values. An apparatus designed to measure dose enhancement to a 0.75 cm3 volume of GNPs from an Ir-192 brachytherapy seed with average energy of 0.38 MeV was built in-house and modeled using MCNP6.2. Burlin cavity correction factors were applied to experimental measurements. The macroscopic DEF was calculated for GNPs of size 30 nm at mass percentages of gold of 0.28%, 0.56% and 0.77%, using the repeating structures capability of MCNP6.2. DEF was calculated by dividing dose to the GNP solution by dose to water in the same volume. The radial dose function and anisotropy factor values at varying angles and distances were accurate when compared against known values. DEFs of 1.018 ± 0.003, 1.031 ± 0.003, and 1.041 ± 0.003 for GNP solutions containing mass percent of gold of 0.28%, 0.56% and 0.77%, respectively, were computed. These DEFs were within 2% of experimental values with Burlin cavity correction factors applied for all three mass percentages of gold.

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Effect of gold nanoparticles on radiation doses in tumor treatment: a Monte Carlo study

Al-Musywel

Laref

2017

Lasers Med Sci

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Radiotherapy is an extensively used treatment for most tumor types. However, ionizing radiation does not discriminate between cancerous and normal cells surrounding the tumor, which can be considered as a dose-limiting factor. This can lead to the reduction of the effectiveness of tumor cell eradication with this treatment. A potential solution to this problem is loading the tumor with high-Z materials prior to radiotherapy as this can induce higher toxicity in tumor cells compared to normal ones. New advances in nanotechnology have introduced the promising use of heavy metal nanoparticles to enhance tumor treatment. The primary studies showed that gold nanoparticles (GNPs) have unique characteristics as biocompatible radiosensitizers for tumor cells. This study aimed to quantify the dose enhancement effect and its radial dose distribution by Monte Carlo simulations utilizing the EGSnrc code for the water-gold phantom loaded with seven different concentrations of Au: 0, 7, 18, 30, 50, 75, and 100 mg-Au/g-water. The phantom was irradiated with two different radionuclide sources, Ir-192 and Cs-137, which are commonly used in brachytherapy, for all concentrations. The results exhibited that gold nanoparticle-aided radiotherapy (GNRT) increases the efficacy of radiotherapy with low-energy photon sources accompanied with high Au concentration loads of up to 30 mg-Au/g-water. Our finding conducts also to the detection of dose enhancement effects in a short average range of 650 μm outside the region loaded with Au. This can indicate that the location determination is highly important in this treatment method.

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Use of Nanoparticles in Brachytherapy – An Alternative for Enhancing Doses in Cancer Treatment

Cited by 5 publications

References 5 publications

Dosimetric comparison between microSelectron iridium-192 and flexi cobalt-60 sources in high-dose-rate brachytherapy using Geant4 Monte Carlo code

Dosimetric comparison between microSelectron iridium-192 and flexi cobalt-60 sources in high-dose-rate brachytherapy using Geant4 Monte Carlo code

A detailed Monte Carlo evaluation of ¹⁹²Ir dose enhancement for gold nanoparticles and comparison with experimentally measured dose enhancements

Effect of gold nanoparticles on radiation doses in tumor treatment: a Monte Carlo study

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Use of Nanoparticles in Brachytherapy – An Alternative for Enhancing Doses in Cancer Treatment

Cited by 5 publications

References 5 publications

Dosimetric comparison between microSelectron iridium-192 and flexi cobalt-60 sources in high-dose-rate brachytherapy using Geant4 Monte Carlo code

Dosimetric comparison between microSelectron iridium-192 and flexi cobalt-60 sources in high-dose-rate brachytherapy using Geant4 Monte Carlo code

A detailed Monte Carlo evaluation of 192Ir dose enhancement for gold nanoparticles and comparison with experimentally measured dose enhancements

Effect of gold nanoparticles on radiation doses in tumor treatment: a Monte Carlo study

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A detailed Monte Carlo evaluation of ¹⁹²Ir dose enhancement for gold nanoparticles and comparison with experimentally measured dose enhancements