Gold Nanoparticle DNA Damage by Photon Beam in a Magnetic Field: A Monte Carlo Study

Jabeen, Mehwish; Chow, James C. L.

doi:10.3390/nano11071751

Cited by 17 publications

(9 citation statements)

References 40 publications

(43 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The simulation geometry is shown in Figure 1. In the simulation geometry, the DNA model as per Henthorn et al was used [35] and defined with a single gold nanoparticle inside a spherical water phantom with a radius of 0.5 µm [36]. The nanoparticle was positioned at the center of the phantom with the proton beam source on the left and the DNA on the right as shown in Figure 1.…”

Section: Simulation Methods and Geometrymentioning

confidence: 99%

DNA Dosimetry with Gold Nanoparticle Irradiated by Proton Beams: A Monte Carlo Study on Dose Enhancement

Huynh

Chow

2021

Applied Sciences

Self Cite

View full text Add to dashboard Cite

Heavy atom nanoparticles, such as gold nanoparticles, are proven effective radiosensitizers in radiotherapy to enhance the dose delivery for cancer treatment. This study investigated the effectiveness of cancer cell killing, involving gold nanoparticle in proton radiation, by changing the nanoparticle size, proton beam energy, and distance between the nanoparticle and DNA. Monte Carlo (MC) simulation (Geant4-DNA code) was used to determine the dose enhancement in terms of dose enhancement ratio (DER), when a gold nanoparticle is present with the DNA. With varying nanoparticle size (radius = 15–50 nm), distance between the gold nanoparticle and DNA (30–130 nm), as well as proton beam energy (0.5–25 MeV) based on the simulation model, our results showed that the DER value increases with a decrease of distance between the gold nanoparticle and DNA and a decrease of proton beam energy. The maximum DER (1.83) is achieved with a 25 nm-radius gold nanoparticle, irradiated by a 0.5 MeV proton beam and 30 nm away from the DNA.

show abstract

Section: Simulation Methods and Geometrymentioning

confidence: 99%

DNA Dosimetry with Gold Nanoparticle Irradiated by Proton Beams: A Monte Carlo Study on Dose Enhancement

Huynh

Chow

2021

Applied Sciences

Self Cite

View full text Add to dashboard Cite

show abstract

“…Early studies have reported initial results suggesting that the biological response to radiation in the presence of a static magnetic field (B-field) may be modestly different when compared to conventional radiotherapy in a zero B-field environment. While the mechanisms of interaction in the presence of a static magnetic field are still an active field of research, the calculation and validation of physical dose will be critical in isolating any biological effects due to treatment in a high-field MR-Linac system (4)(5)(6).…”

Section: Introductionmentioning

confidence: 99%

“…The capability of evaluating daily geometric and anatomical changes along with real-time imaging of tumor position during beam delivery makes on-board MR superior to other imaging modalities for online treatment plan adaptation ( 1 ). The clinical introduction of such MR-guided radiotherapy (MRgRT) systems using hybrid MR-Linac systems have also prompted considerations of the potential impact of the static magnetic field on biological responses to radiation ( 5 , 6 ). Early studies have reported initial results suggesting that the biological response to radiation in the presence of a static magnetic field (B-field) may be modestly different when compared to conventional radiotherapy in a zero B-field environment.…”

Section: Introductionmentioning

confidence: 99%

Integration of an Independent Monitor Unit Check for High-Magnetic-Field MR-Guided Radiation Therapy System

et al. 2022

View full text Add to dashboard Cite

PurposeCommercial independent monitor unit (IMU) check systems for high-magnetic-field MR-guided radiation therapy (RT) systems are lacking. We investigated the feasibility of adopting an existing treatment planning system (TPS) as an IMU check for online adaptive radiotherapy using 1.5-Tesla MR-Linac.MethodsThe 7-MV flattening filter free (FFF) beam and multi-leaf collimator (MLC) models of a 1.5-T Elekta Unity MR-Linac within Monte Carlo-based Monaco TPS were used to generate an optimized beam model in Eclipse TPS. The MLC dosimetric leaf gap of the beam in Eclipse was determined by matching the dose distribution of Eclipse-generated intensity-modulated radiation therapy (IMRT) plans using the Analytical Anisotropic Algorithm (AAA) algorithm to Monaco plans. The plans were automatically adjusted for different source-to-axis distances (SADs) between the two systems. For IMU check, the treatment plans developed in Monaco were transferred to Eclipse to recalculate the dose using AAA. A plug-in within Eclipse was created to perform a 2D gamma analysis of the AAA and Monte Carlo dose distribution on a beam’s eye view parallel plane. Monaco dose distribution was shifted laterally by 2 mm during gamma analysis to account for the impact of magnetic field on electron trajectories. Eclipse doses for posterior beams were corrected for both the Unity couch and the posterior MR coil attenuation. Thirteen patients, each with 4–5 fractions for a variety of tumor sites (pancreas, rectum, and prostate), were tested.ResultsAfter thorough commissioning, the method was implemented as part of the standard clinical workflow. A total of 62 online plans, each with approximately 15 beams, were evaluated. The average per-beam gamma (3%/3 mm) pass rate for plans was 97.9% (range, 95.9% to 98.8%). The average pass rate per beam for all 932 beams used in these plans was 97.9% ± 1.9%, with the lowest per-beam gamma pass rate at 88.4%. The time for the process was within 3.2 ± 0.9 min.ConclusionThe use of a second planning system provides an efficient way to perform IMU checks with clinically acceptable accuracy for online adaptive plans on Unity MR-Linac. This is essential for meeting the safety requirements for second checks as outlined in American Association of Physicists in Medicine Task Group (AAPM TG) reports 114 and 219.

show abstract

“…With the help of Monte Carlo codes (e.g., BEAM and DOSXYZ combined with EGS4), the dose enhancement ratio (DER) due to the addition of gold NPs was quantified based on several parameters; photon beam energies of 140 kVp, 4 MV, and 6 MV spectra with and without flattening filters, and gold NP concentrations of 7, 18, and 30 mg/mL [ 14 ]. These studies inspired many researchers to investigate the role of NPs in radiotherapy, using different types of radiation beams and delivery methods [ 15 , 16 , 17 , 18 ]. This has included skin therapy using orthovoltage photon beams [ 19 ].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Dosimetric Effect of Bone Scatter on Nanoparticle-Enhanced Orthovoltage Radiotherapy: A Monte Carlo Phantom Study

Sadiq

Chow

2022

Nanomaterials

Self Cite

View full text Add to dashboard Cite

In nanoparticle (NP)-enhanced orthovoltage radiotherapy, bone scatter affected dose enhancement at the skin lesion in areas such as the forehead, chest wall, and knee. Since each of these treatment sites have a bone, such as the frontal bone, rib, or patella, underneath the skin lesion and this bone is not considered in dose delivery calculations, uncertainty arises in the evaluation of dose enhancement with the addition of NPs in radiotherapy. To investigate the impact of neglecting the effect of bone scatter, Monte Carlo simulations based on heterogeneous phantoms were carried out to determine and compare the dose enhancement ratio (DER), when a bone was and was not present underneath the skin lesion. For skin lesions with added NPs, Monte Carlo simulations were used to calculate the DER values using different elemental NPs (gold, platinum, silver, iodine, as well as iron oxide), in varying NP concentrations (3–40 mg/mL), at two different photon beam energies (105 and 220 kVp). It was found that DER values at the skin lesion increased with the presence of bone when there was a higher atomic number of NPs, a higher NP concentration, and a lower photon beam energy. When comparing DER values with and without bone, using the same NP elements, NP concentration, and beam energy, differences were found in the range 0.04–3.55%, and a higher difference was found when the NP concentration increased. By considering the uncertainty in the DER calculation, the effect of bone scatter became significant to the dose enhancement (>2%) when the NP concentration was higher than 18 mg/mL. This resulted in an underestimation of dose enhancement at the skin lesion, when the bone underneath the tumour was neglected during orthovoltage radiotherapy.

show abstract

Gold Nanoparticle DNA Damage by Photon Beam in a Magnetic Field: A Monte Carlo Study

Cited by 17 publications

References 40 publications

DNA Dosimetry with Gold Nanoparticle Irradiated by Proton Beams: A Monte Carlo Study on Dose Enhancement

DNA Dosimetry with Gold Nanoparticle Irradiated by Proton Beams: A Monte Carlo Study on Dose Enhancement

Integration of an Independent Monitor Unit Check for High-Magnetic-Field MR-Guided Radiation Therapy System

Evaluation of Dosimetric Effect of Bone Scatter on Nanoparticle-Enhanced Orthovoltage Radiotherapy: A Monte Carlo Phantom Study

Contact Info

Product

Resources

About