A5100732636- Particle accelerators and beam dynamics
- Nuclear Physics and Applications
- Advanced Radiotherapy Techniques
- Superconducting Materials and Applications
- Radiation Therapy and Dosimetry
- Magnetic confinement fusion research
- Radiation Dose and Imaging
- Nuclear reactor physics and engineering
- Advanced Optical Sensing Technologies
- Particle Accelerators and Free-Electron Lasers
- Photorefractive and Nonlinear Optics
- Gyrotron and Vacuum Electronics Research
- Medical Imaging Techniques and Applications
- Advanced Fiber Laser Technologies
- Photonic and Optical Devices
- Atomic and Subatomic Physics Research
- Advanced X-ray and CT Imaging
- High-pressure geophysics and materials
- Digital Radiography and Breast Imaging
- Muon and positron interactions and applications
- Ocular and Laser Science Research
- Solid State Laser Technologies
- Optical measurement and interference techniques
- Internet of Things and Social Network Interactions
- Radiation Detection and Scintillator Technologies
University of Maryland, Baltimore
2017-2023
Oak Ridge National Laboratory
2015-2020
Indiana University Bloomington
2020
University of Missouri
2020
Dankook University
2019
Seoul National University
2016
Spallation Neutron Source
2015
Saint Anne's Hospital
2008
Texas A&M University
2003-2004
Henry Ford Health System
2004
Practical guidelines that are not explicit in the TG-51 protocol and its Addendum for photon beam dosimetry presented implementation of reference external high-energy electron beams. These pertain to: (i) measurement depth-ionization curves required to obtain quality specifiers selection conversion factors, (ii) considerations system specifications a reference-class ionization chamber, (iii) commissioning frequency measurements, (iv) positioning/aligning water tank chamber depth dose (v)...
Background and purposeContouring of organs at risk is important for studying health effects following breast radiotherapy. However, manual contouring time-consuming subject to variability. The purpose this study was develop a deep learning-based method automatically segment multiple structures on radiotherapy planning computed tomography (CT) images.Materials methodsWe used data from 118 patients, including 90 diagnostic CT scans with expert structure delineations training 28 images testing....
Despite the challenges, neutron resonance spin echo still holds promise to improve upon for measurement of slow dynamics in materials. We present a bootstrap, radio frequency flipper using high temperature superconducting technology capable flipping with either nonadiabatic or adiabatic modes. A 2 MHz has been achieved, which would achieve an effective field integral 0.35 T m meter separation spectrometer at current device specifications. In bootstrap mode, self-cancellation Larmor phase...
Although flat-panel based X-ray imaging has been well tested in diagnostic radiology, its use as an image-guided-radiotherapy (IGRT) system a treatment room is new and requires systematic assessment.BrainLab Novalis IGRT was used for this study. It consists of two floor mounted kV tubes projecting obliquely into detectors on the ceiling. The automatically fuses 2D localization images with 3D simulation CT image to provide positioning guidance. following characteristics were studied: (1)...
The analysis of neutron diffraction experiments often assumes that neutrons are elastically scattered from the sample. However, there is growing evidence a significant fraction detected in fact inelastically scattered, especially soft materials and aqueous samples. Ignoring these inelastic contributions gives rise to inaccurate experimental results. To date, has been no simple method with broad applicability for signal separation experiments. Here, we present robust believe could be suited...
To present the results and discuss potential insights gained through surveys on reference dosimetry practices.Two were sent to medical physicists learn about current state of practices at radiation oncology clinics worldwide. A short survey designed maximize response rate was made publicly available distributed via AAPM website a physics list server. Another, much more involved survey, smaller group gain insight detailed practices. The questions diverse, covering topics like measurements...
This paper presents a light detection and ranging (LIDAR) system using electromagnetically actuated two-axis scanning micromirror. The distance measurement with the LIDAR is based on indirect time-of-flight method relative ratio of accumulated charges in capacitors connected to photodiode pixels, which determined by time difference between transmitted reflected pulse. micromirror has double gimbaled structure for actuation circular reflection plate diameter 3 mm. horizontal scan angle 49.13°...
Abstract Purpose The recently published AAPM TG‐275 and the public review version of TG‐315 list new recommendations for comprehensive minimum physics initial chart checks, respectively. This article addresses potential development benefit check automation when these are implemented clinical photon/electron EBRT. Methods Eight board‐certified physicists with 2–20 years experience performed checks using checklists from TG‐315. Manual times were estimated three types plans (IMRT/VMAT, 3D, 2D)...
In this paper, we present a LIDAR(Light Detection And Ranging) system as an application of the MEMS(Micro Electro Mechanical System) scanner that was developed in our previous research. The electromagnetically actuated 2-axis driving MEMS operated about X axis at 1.4 kHz and Y 10 Hz is applied for LIDAR provides measurement distance to object. We adopt indirect time flight method measurement. measured through single laser spot scanning beam using scanner. 1, 2 3 m were 118±15 cm, 207.8±23.4...
Well-designed routine multileaf collimator (MLC) quality assurance (QA) is important to assure external-beam radiation treatment delivery accuracy. This study evaluates the clinical necessity of a comprehensive weekly (C-Weekly) MLC QA program compared American Association Physics in Medicinerecommended picket fence test (PF-Weekly), based on our seven-year experience with QA.The C-Weekly used this includes 5 tests analyze: (1) absolute leaf position; (2) interdigitation (3) positions at...
Electron backscattering is a prominent secondary effect in beta dosimetry, and closely correlated with factors such as the geometries of source scattering material, well composition material. Previous results were varied depending on experimental setup detector resolution, generally performed for monoenergetic electron beams, which makes direct application these to sources difficult. In this work, calculated MCNP 4C selected currently use (32P 90Sr/90Y) potential therapeutic (45Ca, 142Pr...
For prone breast treatment, daily image-guided radiation therapy (IGRT) allows couch shifting to correct position relative the treatment field. This work investigates dosimetric effect of reducing kV imaging frequencies and feasibility optimizing frequency using patient anatomy or their first 3-day shifts.Thirty-seven patients who had been treated with skin marker alignment followed by were retrospectively analyzed. Three IGRT schemes (daily-kV, weekly-kV, no-kV) simulated, assuming that...
This dissertation explores beta dose profiles of microspheres packed in arteries, various source geometries that can be used for therapeutic purposes, and backscatter factors selected sources. A novel treatment method by injecting into feeding arteries arteriovenous malformations (AVM) is under preclinical investigation. To optimize radiation to the clinically important area, i.e., arterial wall, preliminary dosimetric studies were needed. Monte Carlo calculations performed several...
PurposeCyberattacks on health care systems have been the rise over past 5 years. Formulation and implementation of a robust postattack business continuity plan and/or contingency (CP) is essential for minimal disruption to patient care. The level awareness planning within radiation oncology community cyberattacks not clear. This study was undertaken survey assess cyberattack CP preparedness.Methods MaterialsA instrument comprising questions preparedness CPs e-mailed 150 departments....