A5101876696- Advanced X-ray and CT Imaging
- Radiation Therapy and Dosimetry
- Medical Imaging Techniques and Applications
- Advanced Radiotherapy Techniques
- Radiation Dose and Imaging
- Radiation Detection and Scintillator Technologies
- ZnO doping and properties
- Digital Radiography and Breast Imaging
- Metal Alloys Wear and Properties
- Nuclear Physics and Applications
- Microstructure and Mechanical Properties of Steels
- Photoacoustic and Ultrasonic Imaging
- Stability and Control of Uncertain Systems
- Chalcogenide Semiconductor Thin Films
- Electron and X-Ray Spectroscopy Techniques
- Metallurgy and Material Forming
- Nanoplatforms for cancer theranostics
- Semiconductor materials and devices
- Gold and Silver Nanoparticles Synthesis and Applications
- Gas Sensing Nanomaterials and Sensors
- Boron Compounds in Chemistry
- Advanced MRI Techniques and Applications
- Thin-Film Transistor Technologies
- Nanoparticle-Based Drug Delivery
- Optical Imaging and Spectroscopy Techniques
The University of Texas MD Anderson Cancer Center
2016-2025
Korea Advanced Institute of Science and Technology
2023
Chonnam National University
2023
Siemens (United States)
2023
Essar Steel Algoma (Canada)
2013-2020
Georgia Institute of Technology
2007-2016
Radiation Oncology Associates
1999-2016
Sungkyunkwan University
2012-2013
Daegu TechnoPark
2010-2012
Pusan National University
2009-2012
A recent mice study demonstrated that gold nanoparticles could be safely administered and used to enhance the tumour dose during radiation therapy. The use of seems more promising than earlier methods because high atomic number can easily penetrate vasculature. However, date, possible enhancement due has not been well quantified, especially for common treatment situations. Therefore, current preliminary estimated this by Monte Carlo calculations several phantom test cases representing...
We report noninvasive modulation of in vivo tumor radiation response using gold nanoshells. Mild-temperature hyperthermia generated by near-infrared illumination nanoshell-laden tumors, noninvasively quantified magnetic resonance temperature imaging, causes an early increase perfusion that reduces the hypoxic fraction tumors. A subsequent dose induces vascular disruption with extensive necrosis. Gold nanoshells sequestered perivascular space mediate these two vasculature-focused effects to...
A conventional x-ray fluorescence computed tomography (XFCT) technique requires monochromatic synchrotron x-rays to simultaneously determine the spatial distribution and concentration of various elements such as metals in a sample. However, synchrotron-based XFCT appears be unsuitable for vivo imaging under typical laboratory setting. In this study we demonstrated, first time our knowledge, possibility performing small animal-sized object containing gold nanoparticles (GNPs) at relatively...
Purpose: Excessive complexity in intensity‐modulated radiation therapy (IMRT) plans increases the dose uncertainty, prolongs treatment time, and susceptibility to changes patient or target geometry. To date, tools for quantitative assessment of IMRT beam are still lacking. In this study, The authors have sought develop metrics characterize different aspects investigate disease sites. Methods: evaluated scores 65 step‐and‐shoot from three sites (prostate, head neck, spine) 26...
X-ray fluorescence computed tomography (XFCT) is a technique that can identify, quantify, and locate elements within objects by detecting x-ray (characteristic x-rays) stimulated an excitation source, typically derived from synchrotron. However, the use of synchrotron limits practicality accessibility XFCT for routine biomedical imaging applications. Therefore, we have developed ability to perform on benchtop setting with ordinary polychromatic sources. Here, report our postmortem study...
Two-dimensional ordered arrays of honeycomb morphology platinum are fabricated by using anodized aluminum oxide template and metal sputtering methods. The resulting films highly conductible (71 Ω/sq), stretchable (16.8%), transparent (75.2% at 550 nm). presented synthetic strategy is scalable to large area without noticeable defects incorporating the deposition a thin layer silver. In addition, both pore size wall thickness nanomesh straightforwardly controlled with time. As proof concept,...
This report presents the first experimental demonstration, to our knowledge, of benchtop polychromatic cone-beam x-ray fluorescence computed tomography (XFCT) for a simultaneous determination spatial distribution and amount gold nanoparticles (GNPs) within small-animal-sized objects. The current setup successfully produced XFCT images accurately showing regions containing small GNPs (on order 0.1 mg) 3 cm diameter plastic phantom. In particular, performance was improved remarkably (e.g., at...
A recent study investigated the feasibility to develop a bench-top x-ray fluorescence computed tomography (XFCT) system capable of determining spatial distribution and concentration gold nanoparticles (GNPs) in vivo using diagnostic energy range polychromatic (i.e. 110 kVp) pencil-beam source. In this follow-up study, we examined cone-beam implementation XFCT by Monte Carlo (MC) simulations MCNP5 code. current MC model, cylindrical columns with various sizes (5–10 mm diameter) containing...
Gold nanoparticles (GNPs) are promising radiosensitizers in radiation therapy, yet the exact mechanisms behind their effectiveness remain not fully understood. Monte Carlo (MC) simulations have been used to study extra energy deposition and increased DNA damage by secondary electrons from intracellularly present GNPs, which believed be key physical responsible for radiosensitization effects observed many radiobiological studies. However, discrepancies between experimental results...
Inadequate light penetration in tissues restricts photodynamic therapy to treating only superficial tumors. To enable x-ray–excited (XPDT) that targets deep-seated tumors, we synthesized a nanoscintillator-photosensitizer complex containing 5% Eu-doped Y 2 O 3 fluorescing at 611 nanometers and decorated with SiO the scintillation-coupled photosensitizer methylene blue polyethylene glycol coating [PEGylated :Eu@SiO -methylene (pYSM)]. When irradiated, pYSMs generate singlet oxygen species...
This study demonstrates the use of diffuse optical spectroscopy (DOS) for noninvasive measurement gold nanoshell concentrations in tumors live mice. We measured spectra (500-800 nm) using an fiber probe placed contact with tissue surface. performed vitro studies on phantoms illustrating accurate gold-silica concentration within 12.6% known concentration. In vivo were a mouse xenograft tumor model. DOS at preinjection, immediately postinjection, 1 and 24 h postinjection times, verified...
The current study presents the reference photon dosimetry data (RPDD) and phase space (RPSD) for beam from Varian 2100 series linear accelerators. RPDD provide basic data, typically collected during initial commissioning of a new accelerator, including output factors, depth dose profile in air water. RPSD full information, such as position, direction, energy each particle generated inside head any particular accelerator question. dosimetric characteristics majority aforementioned...
Some investigators have shown tumor cell killing enhancement in vitro and regression mice associated with the loading of gold nanoparticles (GNPs) before proton treatments. Several Monte Carlo (MC) investigations also demonstrated GNP-mediated dose enhancement. However, further studies need to be done quantify individual physical factors that contribute or cell-kill (or radiosensitization). Thus, current study investigated contributions particle-induced x-ray emission (PIXE), gamma-ray...
Theoretical investigations suggest that gold nanoparticle (GNP)-mediated radiation dose enhancement and radiosensitization can be maximized when photons interact with gold, predominantly via photoelectric absorption. This makes ytterbium (Yb)-169, which emits an average energy of 93 keV (just above the K-edge gold), ideal radioisotope for such purposes. investigation tests feasibility tumor-specific prostate brachytherapy achievable Yb-169 actively targeted GNPs, using external beam...
Gold nanoparticles can be engineered to target cancerous cells and at the same time designed absorb specific wavelengths of light. Consequently, with presence optically tunable gold such as nanoshells, light effectively converted heat via photothermal effect well enough raise temperature medium surrounding nanoshells for thermal ablation or hyperthermia treatments cancers. In this study, authors proposed a new computational method estimate response embedded in tissue‐like when illuminated by...
Purpose: To develop an accurate and comprehensive Monte Carlo (MC) model of experimental benchtop polychromatic cone‐beam x‐ray fluorescence computed tomography (XFCT) setup apply this MC to optimize incident spectrum for improving production/detection photons from gold nanoparticles (GNPs). Methods: A detailed model, based on XFCT system, was created using the N‐Particle (MCNP) transport code. The validated by comparing results including (XRF) scatter photon spectra with measured data...
In this work, we successfully synthesized a vertically-aligned bimetallic Pt/Pd nanotube array by using anodic aluminum oxide (AAO) template-assisted electro-deposition. The resulting nanostructures exhibited higher catalytic activity in methanol oxidation than either individual constituent (Pt or Pd). facile synthesis of the tubular nanostructure was inspired previously developed thin-walled Pd formation mechanism, which takes advantage surface hydroxyl chemistry AAO template. content Pt...
In this study, zero‐field percent depth dose (PDD) and tissue maximum ratio (TMR) for x rays have been determined by extrapolation from dosimetric measurements over the field size range . The key to small dosimetry is selection of a proper dosimeter measurements, as well alignment detector with central axis (CAX) beam. measured PDD results are compared those obtained Monte Carlo (MC) simulation examine consistency integrity data which extrapolated. Of six most commonly used dosimeters in...
Abstract Transmission electron microscopy (TEM) imaging can be used for detection/localization of gold nanoparticles (GNPs) within tumor cells. However, quantitative analysis GNP-containing cellular TEM images typically relies on conventional/thresholding-based methods, which are manual, time-consuming, and prone to human errors. In this study, therefore, deep learning (DL)–based methods were developed fully automated detection GNPs from images. Several models “you only look once (YOLO)” v5...
Abstract Background Gold nanoparticles (GNPs) accumulated within tumor cells have been shown to sensitize tumors radiotherapy. From a physics point of view, the observed GNP‐mediated radiosensitization is due various downstream effects secondary electron (SE) production from internalized GNPs such as dose enhancement. Over years, numerous computational investigations on enhancement/radiosensitization conducted. However, relied mostly simple cellular geometry models and/or artificial GNP...