Contrast Enhancement for Portal Imaging in Nanoparticle-Enhanced Radiotherapy: A Monte Carlo Phantom Evaluation Using Flattening-Filter-Free Photon Beams

Abdulle, Aniza; Chow, James C. L.

doi:10.3390/nano9070920

Cited by 21 publications

(8 citation statements)

References 41 publications

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“…The use of radiosensitizers may increase the local dose and overcome the heterogeneity of response within hypoxia and rapid proliferative areas of tumors, thereby improving the contrast between tumors and normal tissues for additional therapeutic benefits. 167 , 168 Regarding GNPs, experimental evidence from several in vitro and few in vivo investigations have supported the potential of GNPs as radiosensitizing agents. Radiosensitization by GNPs was initially identified as stem from initiating physical dose enhancement due to the strong photoelectric absorption of Au.…”

Section: Introductionmentioning

confidence: 99%

<p>Gold Nanoparticles as Radiosensitizers in Cancer Radiotherapy</p>

Chen

Yang

Shao

et al. 2020

IJN

182

191

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The rapid development of nanotechnology offers a variety of potential therapeutic strategies for cancer treatment. High atomic element nanomaterials are often utilized as radiosensitizers due to their unique photoelectric decay characteristics. Among them, gold nanoparticles (GNPs) are one of the most widely investigated and are considered to be an ideal radiosensitizers for radiotherapy due to their high X-ray absorption and unique physicochemical properties. Over the last few decades, multidisciplinary studies have focused on the design and optimization of GNPs to achieve greater dosing capability and higher therapeutic effects and highlight potential mechanisms for radiosensitization of GNPs. Although the radiosensitizing potential of GNPs has been widely recognized, its clinical translation still faces many challenges. This review analyses the different roles of GNPs as radiosensitizers in cancer radiotherapy and summarizes recent advances. In addition, the underlying mechanisms of GNP radiosensitization, including physical, chemical and biological mechanisms are discussed, which may provide new directions for the optimization and clinical transformation of next-generation GNPs.

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Section: Introductionmentioning

confidence: 99%

<p>Gold Nanoparticles as Radiosensitizers in Cancer Radiotherapy</p>

Chen

Yang

Shao

et al. 2020

IJN

182

191

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“…Moreover, the dose enhancement can increase cancer cell killing. Second, due to the increase in the deviation of beam absorption between the target (with gold nanoparticle addition) and its surrounding tissue (without gold nanoparticle addition), contrast enhancement can be achieved in medical imaging modalities such as computed tomography (CT) using a kV photon beam [ 9 , 10 , 11 ]. The increase in target contrast will make it easier for the radiation oncologist to identify the tumor and contour it more accurately in radiation treatment planning.…”

Section: Introductionmentioning

confidence: 99%

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

Jabeen

Chow

2021

Nanomaterials

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Ever since the emergence of magnetic resonance (MR)-guided radiotherapy, it is important to investigate the impact of the magnetic field on the dose enhancement in deoxyribonucleic acid (DNA), when gold nanoparticles are used as radiosensitizers during radiotherapy. Gold nanoparticle-enhanced radiotherapy is known to enhance the dose deposition in the DNA, resulting in a double-strand break. In this study, the effects of the magnetic field on the dose enhancement factor (DER) for varying gold nanoparticle sizes, photon beam energies and magnetic field strengths and orientations were investigated using Geant4-DNA Monte Carlo simulations. Using a Monte Carlo model including a single gold nanoparticle with a photon beam source and DNA molecule on the left and right, it is demonstrated that as the gold nanoparticle size increased, the DER increased. However, as the photon beam energy decreased, an increase in the DER was detected. When a magnetic field was added to the simulation model, the DER was found to increase by 2.5–5% as different field strengths (0–2 T) and orientations (x-, y- and z-axis) were used for a 100 nm gold nanoparticle using a 50 keV photon beam. The DNA damage reflected by the DER increased slightly with the presence of the magnetic field. However, variations in the magnetic field strength and orientation did not change the DER significantly.

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“…Mitotic death is the most common form of cell death caused by radiation; it occurs when cells die while in the process of mitosis due to damaged chromosomes. Recently, many studies focused on the development of radiosensitizers such as heavy-atom nanoparticles in radiotherapy [3][4][5][6][7][8]. These nanomaterials aggregate in the cell because of the interactions with glutathione present in cytosol.…”

Section: Introductionmentioning

confidence: 99%

Dose Enhancement for the Flattening-Filter-Free and Flattening-Filter Photon Beams in Nanoparticle-Enhanced Radiotherapy: A Monte Carlo Phantom Study

Martelli

Chow

2020

Nanomaterials

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Monte Carlo simulations were used to predict the dose enhancement ratio (DER) using the flattening-filter-free (FFF) and flattening-filter (FF) photon beams in prostate nanoparticle-enhanced radiotherapy, with multiple variables such as nanoparticle material, nanoparticle concentration, prostate size, pelvic size, and photon beam energy. A phantom mimicking the patient’s pelvis with various prostate and pelvic sizes was used. Macroscopic Monte Carlo simulation using the EGSnrc code was used to predict the dose at the prostate or target using the 6 MV FFF, 6 MV FF, 10 MV FFF, and 10 MV FF photon beams produced by a Varian TrueBeam linear accelerator (Varian Medical System, Palo Alto, CA, USA). Nanoparticle materials of gold, platinum, iodine, silver, and iron oxide with concentration varying in the range of 3–40 mg/ml were used in simulations. Moreover, the prostate and pelvic size were varied from 2.5 to 5.5 cm and 20 to 30 cm, respectively. The DER was defined as the ratio of the target dose with nanoparticle addition to the target dose without nanoparticle addition in the simulation. From the Monte Carlo results of DER, the best nanoparticle material with the highest DER was gold, based on all the nanoparticle concentrations and photon beams. Smaller prostate size, smaller pelvic size, and a higher nanoparticle concentration showed better DER results. When comparing energies, the 6 MV beams always had the greater enhancement ratio. In addition, the FFF photon beams always had a better DER when compared to the FF beams. It is concluded that gold nanoparticles were the most effective material in nanoparticle-enhanced radiotherapy. Moreover, lower photon beam energy (6 MV), FFF photon beam, higher nanoparticle concentration, smaller pelvic size, and smaller prostate size would all increase the DER in prostate nanoparticle-enhanced radiotherapy.

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Contrast Enhancement for Portal Imaging in Nanoparticle-Enhanced Radiotherapy: A Monte Carlo Phantom Evaluation Using Flattening-Filter-Free Photon Beams

Cited by 21 publications

References 41 publications

<p>Gold Nanoparticles as Radiosensitizers in Cancer Radiotherapy</p>

<p>Gold Nanoparticles as Radiosensitizers in Cancer Radiotherapy</p>

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

Dose Enhancement for the Flattening-Filter-Free and Flattening-Filter Photon Beams in Nanoparticle-Enhanced Radiotherapy: A Monte Carlo Phantom Study

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