Monte Carlo simulation of dose enhancement due to silver nanoparticles implantation in brain tumor brachytherapy using a digital phantom

Taha, Eslam; Djouider, Fathi; Banoqitah, Essam

doi:10.1016/j.radphyschem.2018.10.027

Cited by 12 publications

(7 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The obtained values of the OER relative to pressure of O 2 shown in Figure 4 have a behavior similar to an increasing logarithm function as found in literature [49,[51][52][53][54]. After the 60 mmHg of pressure of O 2 , the OER values have a trend to value constant.…”

Section: Discussionsupporting

confidence: 84%

Evaluation by Monte Carlo Simulation of Doses Distribution in Tumors with Hypoxia

Alva-Sánchez¹,

Pianoschi²

2021

Translational Research in Cancer

View full text Add to dashboard Cite

Radiotherapy is one of the most useful modalities applied for tumor treatments, which use ionization radiation to eradicate the tumor, in major cases. Cells with normal oxygenation are more sensitive to the effects of ionizing radiation than those with hypoxic conditions, because O 2 molecules react rapidly with free radicals, produced by irradiation, originating highly reactive radicals. Thus, the different concentrations of hypoxia in tumors can modulate the response of the irradiation through the radioresistance they present and consequently the success of the treatment. This chapter deals with the dose distributions in cranial tumors with different concentrations of hypoxia through a code based on Monte Carlo simulation.

show abstract

Section: Discussionsupporting

confidence: 84%

Evaluation by Monte Carlo Simulation of Doses Distribution in Tumors with Hypoxia

Alva-Sánchez¹,

Pianoschi²

2021

Translational Research in Cancer

View full text Add to dashboard Cite

show abstract

“…The average enhancement was not considered in this study, as it is highly dependent on the tumor size [11]. Changing the tumor size will affect the dose enhancement distribution and, consequently, the average DEF.…”

Section: Resultsmentioning

confidence: 99%

“…In the last few decades, nanoparticles (NPs) have been increasingly investigated as radio-sensitizers that enhance radiation damage to cancer cells. In this perspective, NPs with a high atomic number Z-gold [8], gadolinium, [9] bismuth, [10] and silver [11]implanted inside a tumor can increase the production of secondary electrons and Auger electrons by the photoelectric effect when irradiated with photons of low energy E, as the cross-section of this interaction varies as with 4 < n < 5 [12]. This local dose intensification, in turn, may enhance the radiation therapy effects [13].…”

Section: Introductionmentioning

confidence: 99%

Estimation of Dose Enhancement for Inhomogeneous Distribution of Nanoparticles: A Monte Carlo Study

et al. 2021

Self Cite

View full text Add to dashboard Cite

High atomic number nanoparticles are of increasing interest in radiotherapy due to their significant positive impact on the local dose applied to the treatment site. In this work, three types of metal nanoparticles were utilized to investigate their dose enhancement based on the GATE Monte Carlo simulation tool. Gold, gadolinium, and silver were implanted at three different concentrations to a 1 cm radius sphere to mimic a cancerous tumor inside a 10 × 10 × 30 cm3 water phantom. The innermost layer of the tumor represents a necrotic region, where the metal nanoparticles uptake is assumed to be zero, arising from hypoxic conditions. The nanoparticles were defined using the mixture technique, where nanoparticles are added to the chemical composition of the tumor. A directional 2 × 2 cm2 monoenergetic photon beam was used with several energies ranging from 50 keV to 4000 keV. The dose enhancement factor (DEF) was measured for all three metal nanoparticles under all beam energies. The maximum DEF was ~7 for silver nanoparticles with the 50 keV beam energy at the highest nanoparticle concentration of 30 mg/g of water. Gold followed the same trend as it registered the highest DEF at the 50 keV beam energy with the highest concentration of nanoparticles at 30 mg/g, while gadolinium registered the highest at 100 keV.

show abstract

“…In order to verify the effectiveness and accuracy of the proposed TG‐43‐DP‐ICF, dose distributions surrounding the single‐seed‐loaded stent and the 16‐seed‐loaded stent were calculated by TG‐43‐DP‐ICF not only in water phantom but also for three real patient cases who had received the treatment of seed‐loaded stent implantation. The digital voxelized phantoms were constructed from the postimplantation CTs using GATE 27 according to a correlation between HU value and mass density as well as elemental weights. The default volume weighting algorithm was adopted, which means that the dose inside a dose grid was computed as the sum of the absorbed dose of the volume voxels contained in that dose grid weighted by their respective volume fractions 28 .…”

Section: Methodsmentioning

confidence: 99%

Technical note: A fast and accurate analytical dose calculation algorithm for ¹²⁵I seed‐loaded stent applications

et al. 2021

View full text Add to dashboard Cite

The safety and clinical efficacy of 125 I seed-loaded stent for the treatment of portal vein tumor thrombosis (PVTT) have been shown. Accurate and fast dose calculation of the 125 I seeds with the presence of the stent is necessary for the plan optimization and evaluation. However, the dosimetric characteristics of the seed-loaded stents remain unclear and there is no fast dose calculation technique available. This paper aims to explore a fast and accurate analytical dose calculation method based on Monte Carlo (MC) dose calculation, which takes into account the effect of stent and tissue inhomogeneity. Methods: A detailed model of the seed-loaded stent was developed using 3D modeling software and subsequently used in MC simulations to calculate the dose distribution around the stent. The dose perturbation caused by the presence of the stent was analyzed, and dose perturbation kernels (DPKs) were derived and stored for future use. Then, the dose calculation method from AAPM TG-43 was adapted by integrating the DPK and appropriate inhomogeneity correction factors (ICF) to calculate dose distributions analytically. To validate the proposed method, several comparisons were performed with other methods in water phantom and voxelized CT phantoms for three patients. Results:The stent has a considerable dosimetric effect reducing the dose up to 47.2% for single-seed stent and 11.9%-16.1% for 16-seed stent. In a water phantom, dose distributions from MC simulations and TG-43-DP-ICF showed a good agreement with the relative error less than 3.3%. In voxelized CT phantoms, taking MC results as the reference, the relative errors of TG-43 method can be up to 33%, while those of TG-43-DP-ICF method were less than 5%. For a dose matrix with 256 × 256 × 46 grid (corresponding to a phantom of 17.2 × 17.2 × 11.5 cm 3 ) for 16-seed-loaded stent, it only takes 17 s for TG-43-DP-ICF to compute, compared to 25 h for the full MC calculation. Conclusions: The combination of DPK and inhomogeneity corrections is an effective approach to handle both the presence of stent and tissue heterogeneity. Exhibiting good agreement with MC calculation and computational efficiency, the proposed TG-43-DP-ICF method is adequate for dose evaluation and optimization in seed-loaded stent implantation treatment planning.

show abstract

Monte Carlo simulation of dose enhancement due to silver nanoparticles implantation in brain tumor brachytherapy using a digital phantom

Cited by 12 publications

References 32 publications

Evaluation by Monte Carlo Simulation of Doses Distribution in Tumors with Hypoxia

Evaluation by Monte Carlo Simulation of Doses Distribution in Tumors with Hypoxia

Estimation of Dose Enhancement for Inhomogeneous Distribution of Nanoparticles: A Monte Carlo Study

Technical note: A fast and accurate analytical dose calculation algorithm for ¹²⁵I seed‐loaded stent applications

Contact Info

Product

Resources

About

Monte Carlo simulation of dose enhancement due to silver nanoparticles implantation in brain tumor brachytherapy using a digital phantom

Cited by 12 publications

References 32 publications

Evaluation by Monte Carlo Simulation of Doses Distribution in Tumors with Hypoxia

Evaluation by Monte Carlo Simulation of Doses Distribution in Tumors with Hypoxia

Estimation of Dose Enhancement for Inhomogeneous Distribution of Nanoparticles: A Monte Carlo Study

Technical note: A fast and accurate analytical dose calculation algorithm for 125I seed‐loaded stent applications

Contact Info

Product

Resources

About

Technical note: A fast and accurate analytical dose calculation algorithm for ¹²⁵I seed‐loaded stent applications