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https://www.readbyqxmd.com/read/28717826/operator-radiation-exposure-during-transradial-coronary-angiography-effect-of-single-vs-double-catheters
#1
A Tarighatnia, L Pourafkari, A Farajollahi, A H Mohammadalian, M Ghojazadeh, N D Nader
BACKGROUND: The right radial artery has gained popularity as the preferred access site for coronary angiography. To save time and limit the radiation exposure of operators and patients, newly designed catheters can be used to access both the right and left coronary arteries. The aim of this study was to compare operator radiation exposure between single-catheter (SCA) and two-catheter approaches (TCA). METHODS: In all, 256 patients undergoing diagnostic coronary angiography via the right radial artery in a high-volume medical center were randomized to either the SCA or TCA group...
July 17, 2017: Herz
https://www.readbyqxmd.com/read/28712278/in-vivo-dosimetry-and-acute-toxicity-in-breast-cancer-patients-undergoing-intraoperative-radiotherapy-as-boost
#2
Jason Joon Bock Lee, Jinhyun Choi, Sung Gwe Ahn, Joon Jeong, Ik Jae Lee, Kwangwoo Park, Kangpyo Kim, Jun Won Kim
PURPOSE: To report the results of a correlation analysis of skin dose assessed by in vivo dosimetry and the incidence of acute toxicity. This is a phase 2 trial evaluating the feasibility of intraoperative radiotherapy (IORT) as a boost for breast cancer patients. MATERIALS AND METHODS: Eligible patients were treated with IORT of 20 Gy followed by whole breast irradiation (WBI) of 46 Gy. A total of 55 patients with a minimum follow-up of 1 month after WBI were evaluated...
June 2017: Radiation Oncology Journal
https://www.readbyqxmd.com/read/28708603/monte-carlo-skin-dose-simulation-in-intraoperative-radiotherapy-of-breast-cancer-using-spherical-applicators
#3
Farhad Moradi, Ngie Min Ung, M U Khandaker, Ghafour Amouzad Mahdiraji, Marniza Saad, Rozita Abdul Malik, Anita Zarina Bustam, Zainor Zaili, David A Bradley
The relatively new treatment modality electronic intraoperative radiotherapy (IORT) is gaining popularity, irradiation being obtained within a surgically produced cavity being delivered via a low-energy X-ray source and spherical applicators, primarily for early stage breast cancer. Due to the spatially dramatic dose-rate fall off with radial distance from the source and effects related to changes in the beam quality of the low keV photon spectra, dosimetric account of the Intrabeam system is rather complex...
July 14, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28706352/monte-carlo-calculation-of-beam-quality-and-phantom-scatter-corrections-for-lithium-formate-electron-paramagnetic-resonance-dosimeter-for-high-energy-brachytherapy-dosimetry
#4
Subhalaxmi Mishra, T Palani Selvam
PURPOSE: To investigate beam quality correction, KQQ0 (r) and phantom scatter correction, Kphan (r) for lithium formate dosimeter as a function of distance r along the transverse axis of the high-energy brachytherapy sources (60)Co, (137)Cs, (192)Ir and (169)Yb using the Monte Carlo-based EGSnrc code system. MATERIALS AND METHODS: The brachytherapy sources investigated in this study are BEBIG High Dose Rate (HDR) (60)Co (model Co0.A86), (137)Cs (model RTR), HDR (192)Ir (model Microselectron) and HDR (169)Yb (model 4140)...
April 2017: Journal of Medical Physics
https://www.readbyqxmd.com/read/28706350/investigating-the-electronic-portal-imaging-device-for-small-radiation-field-measurements
#5
Arpita Agarwal, Nikhil Rastogi, K J Maria Das, S A Yoganathan, D Udayakumar, Shaleen Kumar
PURPOSE: With the advent of state-of-the-art treatment technologies, the use of small fields has increased, and dosimetry in small fields is highly challenging. In this study, the potential use of Varian electronic portal imaging device (EPID) for small field measurements was explored for 6 and 15 MV photon beams. MATERIALS AND METHODS: The output factors and profiles were measured for a range of jaw-collimated square field sizes starting from 0.8 cm × 0.8 cm to 10 cm × 10 cm using EPID...
April 2017: Journal of Medical Physics
https://www.readbyqxmd.com/read/28704443/dosimetric-characteristics-of-a-reusable-3d-radiochromic-dosimetry-material
#6
Jong Min Park, So-Yeon Park, Chang Heon Choi, Minsoo Chun, Ji Hye Han, Jin Dong Cho, Jung-In Kim
PURPOSE: To investigate the dosimetric characteristics of PRESAGEREU dosimeters. METHODS: Commercially available PRESAGEREU dosimeters (size of 10 mm × 10 mm × 45 mm) were divided into two groups, with one of the groups placed at room temperature of 22°C (RT group) and another group placed at low temperature of 10°C (LT group). A total of 3 dosimeters (set of dosimeters) were irradiated at a time, with doses of 1 Gy, 2 Gy, 4 Gy, 8 Gy, 12 Gy, 16 Gy, and 20 Gy, at a nominal dose rate of 400 MU/min at temperature of 22°C...
2017: PloS One
https://www.readbyqxmd.com/read/28701665/the-clinical-applications-of-polymer-gel-dosimetry-using-mri
#7
Kaoru Ono
Polymer gel dosimeters are devices that utilize the radiation-induced polymerization reactions of vinyl monomers in a gel to store information of radiation dose. They have some advantages over other dosimeters as the visual conformation and the direct read-out of three-dimensional (3D) radiation dose information for the dosimetric verification of intensity modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT), and stereotactic radiotherapy (SRT) with steep dose gradients. In this report, the dosimetric uncertainties and potential for clinical applications of polymer gel dosimetry by the in-house developed 3D dose verification system for IMRT and VMAT QA is outlined...
2017: Japanese Journal of Medical Physics
https://www.readbyqxmd.com/read/28688159/aapm-tg-158-measurement-and-calculation-of-doses-outside-the-treated-volume-from-external-beam-radiation-therapy
#8
Stephen F Kry, Bryan Bednarz, Rebecca M Howell, Larry Dauer, David Followill, Eric Klein, Harald Paganetti, Brian Wang, Cheng-Shie Wuu, X George Xu
The introduction of advanced techniques and technology in radiotherapy has greatly improved our ability to deliver highly conformal tumor doses while minimizing the dose to adjacent organs at risk. Despite these tremendous improvements there remains a general concern about doses to normal tissues that are not the target of the radiation treatment; any "non-target" radiation should be minimized as it offers no therapeutic benefit. As patients live longer after treatment, there is increased opportunity for late effects including second cancers and cardiac toxicity to manifest...
July 8, 2017: Medical Physics
https://www.readbyqxmd.com/read/28688151/physical-validation-of-a-monte-carlo-based-phantom-derived-approach-to-computed-tomography-organ-dosimetry-under-tube-current-modulation
#9
Elliott J Stepusin, Daniel J Long, Kayla Ficarrotta, David Hintenlang, Wesley E Bolch
PURPOSE: To physically validate the accuracy of a Monte Carlo-based, phantom-derived methodology for computed tomography (CT) dosimetry that utilizes organ doses from pre-computed axial scans and that accounts for tube current modulation (TCM). METHODS: The output of a Toshiba Aquilion ONE CT scanner was modeled, based on physical measurement, in the Monte Carlo radiation transport code MCNPX (v2.70). CT examinations were taken of two anthropomorphic phantoms representing pediatric and adult patients (15-year-old female and adult male) at various energies, in which physical organ dose measurements were made using optically stimulated luminesce dosimeters (OSLDs)...
July 8, 2017: Medical Physics
https://www.readbyqxmd.com/read/28687290/a-pilot-study-investigating-two-dose-reduction-techniques-for-ap-lumbar-spine-radiography-using-direct-dosimetry-and-projection-vr
#10
M C Shanahan
INTRODUCTION: The purpose of this study was to compare radiation dose measurements generated using a virtual radiography simulation with experimental dosimeter measurements for two radiation dose reduction techniques in digital radiography. METHODS: Entrance Surface Dose (ESD) measurements were generated for an antero-posterior lumbar spine radiograph experimentally using NanoDOT™, single point dosimeters, for two radiographic systems (systems 1 and 2) and using Projection VR™, a virtual radiography simulation (system 3)...
August 2017: Radiography
https://www.readbyqxmd.com/read/28687288/does-collimation-affect-patient-dose-in-antero-posterior-thoraco-lumbar-spine
#11
J B Robinson, R M Ali, A K Tootell, P Hogg
INTRODUCTION: The purpose of this study is to determine the effect of collimation on the lifetime attributable risk (LAR) of cancer incidence in all body organs (effective risk) in patients undergoing antero-posterior (AP) examinations of the spine. This is of particular importance for patients suffering from scoliosis as in their case regular repeat examinations are required and also because such patients are usually young and more susceptible to the effects of ionising radiation than are older patients...
August 2017: Radiography
https://www.readbyqxmd.com/read/28682791/individual-external-dose-monitoring-of-all-citizens-of-date-city-by-passive-dosimeter-5-to-51-months-after-the-fukushima-npp-accident-series-ii-prediction-of-lifetime-additional-effective-dose-and-evaluating-the-effect-of-decontamination-on-individual-dose
#12
Makoto Miyazaki, Ryugo Hayano
In the first paper of this series, we showed that the ratio c of individual dose to ambient dose did not change with time in Date City, Fukushima Prefecture, after the Fukushima Daiichi Nuclear Power Plant accident. The purpose of the present paper, the second in a series, is to estimate the lifetime doses of the Date City residents, based on continuous glass badge monitoring data, extrapolated by means of the ambient-dose-rate reduction function obtained from the airborne monitoring data. As a result, we found that the external exposure contribution to the mean additional lifetime dose of residents living in Date City is not expected to exceed 18 mSv...
July 6, 2017: Journal of Radiological Protection: Official Journal of the Society for Radiological Protection
https://www.readbyqxmd.com/read/28676266/frequencies-of-micronucleated-reticulocytes-a-dosimeter-of-dna-double-strand-breaks-in-infants-receiving-computed-tomography-or-cardiac-catheterization
#13
Mona Khattab, Dale M Walker, Richard J Albertini, Janice A Nicklas, Lennart K A Lundblad, Pamela M Vacek, Vernon E Walker
The use of computed tomography (CT scans) has increased dramatically in recent decades, raising questions about the long-term safety of CT-emitted x-rays especially in infants who are more sensitive to radiation-induced effects. Cancer risk estimates for CT scans typically are extrapolated from models; therefore, new approaches measuring actual DNA damage are needed for improved estimations. Hence, changes in a dosimeter of DNA double-strand breaks, micronucleated reticulocytes (MN-RETs) measured by flow cytometry, were investigated in mice and infants exposed to CT scans...
August 2017: Mutation Research
https://www.readbyqxmd.com/read/28666901/characterization-of-the-effect-of-a-new-commercial-transmission-detector-on-radiation-therapy-beams
#14
Joey P Cheung, Angelica Perez-Andujar, Olivier Morin
PURPOSE: To evaluate the influence of a new commercial transmission detector on radiation therapy beams. METHODS AND MATERIALS: A transmission detector designed for online treatment monitoring was characterized on a TrueBeam STx linear accelerator with 6-MV, 6-flattening filter free, 10-MV, and 10-flattening filter free beams. Measurements of percentage depth doses, in-plane and cross-plane off-axis profiles at different depths, transmission factors, and skin dose were acquired with 3 × 3, 5 × 5, 10 × 10, 20 × 20, and 40 × 40 cm(2) field sizes at 100 cm and 80 cm source-to-surface distance (SSD)...
April 9, 2017: Practical Radiation Oncology
https://www.readbyqxmd.com/read/28658058/influence-of-a-commercial-lead-apron-on-patient-skin-dose-delivered-during-oral-and-maxillofacial-examinations-under-cone-beam-computed-tomography-cbct
#15
Ralf Kurt Willy Schulze, Mahssa Sazgar, Heiko Karle, Hugo de Las Heras Gala
The purpose of this paper is to investigate the impact of a commercial lead apron on patient skin dose delivered during maxillofacial CBCT in five critical regions by means of solid-state-dosimetry. Five anatomical regions (thyroid gland, left and right breast, gonads, back of the phantom torso) in an adult female anthropomorphic phantom were selected for dose measurement by means of the highly sensitive solid-state dosimeter QUART didoSVM. Ten repeated single exposures were assessed for each patient body region for a total of five commercial CBCT devices with and without a lead apron present...
August 2017: Health Physics
https://www.readbyqxmd.com/read/28643752/dosimetric-characterization-of-optically-stimulated-luminescence-dosimeter-with-therapeutic-photon-beams-for-use-in-clinical-radiotherapy-measurements
#16
Retna Ponmalar, Ravikumar Manickam, K M Ganesh, Sathiyan Saminathan, Arun Raman, Henry Finlay Godson
AIM: The modern radiotherapy techniques impose new challenges for dosimetry systems with high precision and accuracy in in vivo and in phantom dosimetric measurements. The knowledge of the basic characterization of a dosimetric system before patient dose verification is crucial. This incites the investigation of the potential use of nanoDot optically stimulated luminescence dosimeter (OSLD) for application in radiotherapy with therapeutic photon beams. MATERIALS AND METHODS: Measurements were carried out with nanoDot OSLDs to evaluate the dosimetric characteristics such as dose linearity, dependency on field size, dose rate, energy and source-to-surface distance (SSD), reproducibility, fading effect, reader stability, and signal depletion per read out with cobalt-60 (60 Co) beam, 6 and 18 MV therapeutic photon beams...
April 2017: Journal of Cancer Research and Therapeutics
https://www.readbyqxmd.com/read/28643518/mini-c-arm-fluoroscopy-does-its-configuration-matter-for-radiation-exposure-to-the-surgeon
#17
Talia Chapman, Dennis P Martin, Christopher Williamson, Brian Tinsley, Mark L Wang, Asif M Ilyas
BACKGROUND: The risk of occupational radiation exposure to the surgeon associated with the use of a mini C-arm has yet to reach a wide consensus. Using a distal radius fracture surgery model, we tested the hypothesis that radiation exposure to the surgeon's critical body parts is independent of mini C-arm configuration. METHODS: An anthropomorphic mannequin (representing the upper body of a 60" male surgeon) was seated at a hand table as if operating on a volar-plated wrist Sawbone model...
June 1, 2017: Hand: Official Journal of the American Association for Hand Surgery
https://www.readbyqxmd.com/read/28638277/titanium-dioxide-nanoparticles-as-radiosensitisers-an-in-vitro-and-phantom-based-study
#18
Esho Qasho Youkhana, Bryce Feltis, Anton Blencowe, Moshi Geso
Objective: Radiosensitisation caused by titanium dioxide nanoparticles (TiO2-NPs) is investigated using phantoms (PRESAGE(®) dosimeters) and in vitro using two types of cell lines, cultured human keratinocyte (HaCaT) and prostate cancer (DU145) cells. Methods: Anatase TiO2-NPs were synthesised, characterised and functionalised to allow dispersion in culture-medium for in vitro studies and halocarbons (PRESAGE(®) chemical compositions). PRESAGE(®) dosimeters were scanned with spectrophotometer to determine the radiation dose enhancement...
2017: International Journal of Medical Sciences
https://www.readbyqxmd.com/read/28637959/examination-of-dose-reduction-using-image-noise-reduction-technology-in-cardiovascular-x-ray-systems
#19
Takaya Saijo, Shigenobu Seguchi
The aim of this study is to establish radiation exposure dose reduction protocols during cardiac intervention by decreasing the entrance dose at flat panel detector (FPD) with image quality evaluations. For measuring entrance surface dose (ESD), we have used a Radical 9015 dosimeter (6 cc ion chamber) placed under 20 cm thick acrylic plates at the patient's entrance reference point. We performed an image quality assessment based on quantitative as well as visual evaluation of the images obtained via current and dose reduction protocols...
2017: Nihon Hoshasen Gijutsu Gakkai Zasshi
https://www.readbyqxmd.com/read/28635402/analysing-the-vocal-behaviour-of-teachers-during-classroom-teaching-using-a-portable-voice-accumulator
#20
Manfred Nusseck, Bernhard Richter, Claudia Spahn, Matthias Echternach
PURPOSE: Teachers are at a considerable risk of developing vocal health problems due to intensive voice use during teaching. This study investigated factors related to the teacher's voice during a teaching situation. METHODS: Overall, 113 teachers were recorded during a typical class lesson, lasting on average 48 min. A portable voice dosimeter (VoxLog System) was used to measure the sound pressure level (SPL) of the noise in the classroom, the teacher's voice SPL, the fundamental frequency (fo) and the phonation time...
March 3, 2017: Logopedics, Phoniatrics, Vocology
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