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Radiation dose measurements

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https://www.readbyqxmd.com/read/28650775/urine-interleukin-18-il-18-as-a-biomarker-of-total-body-irradiation-a-preliminary-study-in-nonhuman-primates
#1
Mang Xiao, David L Bolduc, XiangHong Li, Wanchang Cui, Kevin P Hieber, Rolf Bünger, Natalia I Ossetrova
We have reported that circulating IL-18 can be used as a radiation biomarker in mice, minipigs and nonhuman primates (NHPs, Macaca mulatta). Here, we report the levels of IL-18 in individual NHP's urine before and at 6 h-7 days after 5.0, 6.5 and 8.5 Gy (60)Co total-body irradiation (TBI) using enzyme linked immunosorbent assay (ELISA). Six animals (3.5-5.5 kg, 3-4 years old) per radiation dose were investigated. Correlation values between urine IL-18 and blood cell counts and serum chemistry parameters including lactate dehydrogenase (LDH), lipase, and serum total protein (TP), as well as between urine IL-18 and 60-day survival, were analyzed...
June 26, 2017: Radiation Research
https://www.readbyqxmd.com/read/28649154/skin-dose-mapping-for-non-uniform-x-ray-fields-using-a-backscatter-point-spread-function
#2
Sarath Vijayan, Zhenyu Xiong, Alok Shankar, Stephen Rudin, Daniel R Bednarek
Beam shaping devices like ROI attenuators and compensation filters modulate the intensity distribution of the x-ray beam incident on the patient. This results in a spatial variation of skin dose due to the variation of primary radiation and also a variation in backscattered radiation from the patient. To determine the backscatter component, backscatter point spread functions (PSF) are generated using EGS Monte-Carlo software. For this study, PSF's were determined by simulating a 1 mm beam incident on the lateral surface of an anthropomorphic head phantom and a 20 cm thick PMMA block phantom...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28648410/the-great-unknown-a-systematic-literature-review-about-risk-associated-with-intraoperative-imaging-during-orthopaedic-surgeries
#3
REVIEW
Amir Matityahu, Ryan K Duffy, Sabine Goldhahn, Alexander Joeris, Peter H Richter, Florian Gebhard
INTRODUCTION: Modern techniques in orthopaedic surgery using minimally invasive procedures, and increased use of fluoroscopic imaging present a potential increased risk to surgeons due to ionizing radiation exposure. This article is a systematic review of recent literature on radiation exposure of orthopaedic surgeons. MATERIALS AND METHODS: Pubmed and Cochrane searches were performed on intraoperative radiation exposure covering English and German articles published between 1...
April 21, 2017: Injury
https://www.readbyqxmd.com/read/28646736/cell-damage-caused-by-ultraviolet-b-radiation-in-the-desert-cyanobacterium-phormidium-tenue-and-its-recovery-process
#4
Gaohong Wang, Songqiang Deng, Jiafeng Liu, Chaoran Ye, Xiangjun Zhou, Lanzhou Chen
Phormidium tenue, a cyanobacterium that grows in the topsoil of biological soil crusts (BSCs), has the highest recovery rate among desert crust cyanobacteria after exposure to ultraviolet B (UV-B) radiation. However, the mechanism underlying its recovery process is unclear. To address this issue, we measured chlorophyll a fluorescence, generation of reactive oxygen species (ROS), lipid peroxidation, and repair of DNA breakage in P. tenue following exposure to UV-B. We found that UV-B radiation at all doses tested reduced photosynthesis and induced cell damage in P...
June 21, 2017: Ecotoxicology and Environmental Safety
https://www.readbyqxmd.com/read/28644765/radioactivity-measurements-and-dosimetric-evaluation-in-meat-of-wild-birds
#5
Carla Roselli, Donatella Desideri, Chiara Cantaluppi, Federica Ceccotto, Laura Feduzi, Maria Assunta Meli
The aim of this study was to determine the background activity concentration of natural radionuclides and (137)Cesium (Cs) in meat of 14 migratory birds originating from central and northern Europe. This meat is largely consumed by the Italian population. (40)K, (210)Pb, and (137)Cs were determined by gamma spectrometry and (210)Po by alpha spectrometry. The mean (40)K activity concentration detected was 490 ± 117 Bq/kgdw. In all the samples, (210)Pb was below the limit of detection (LOD), and therefore it was not possible to calculate the ratio (210)Po/(210)Pb...
June 23, 2017: Journal of Toxicology and Environmental Health. Part A
https://www.readbyqxmd.com/read/28643737/changes-in-pharyngeal-constrictor-volumes-during-head-and-neck-radiation-therapy-implications-for-dose-delivery
#6
Akila Kumarasiri, Chang Liu, Mona Kamal, Correen Fraser, Stephen Brown, Indrin J Chetty, Jinkoo Kim, Farzan Siddiqui
OBJECTIVE: The objective of this study was to evaluate the anatomical changes and associated dosimetric consequences to pharyngeal constrictor muscles (PCMs) that occur during head and neck (H and N) radiotherapy (RT). MATERIALS AND METHODS: A cohort of 13 oropharyngeal cancer patients with daily cone beam computed tomography (CBCT) was retrospectively studied. On every 5th CBCT image, PCM was manually delineated by a radiation oncologist. The anterior-posterior PCM thickness was measured at the midline level of C3 vertebral body...
April 2017: Journal of Cancer Research and Therapeutics
https://www.readbyqxmd.com/read/28641969/determining-3d-kinematics-of-the-hip-using-video-fluoroscopy-guidelines-for-balancing-radiation-dose-and-registration-accuracy
#7
Fabio D'Isidoro, Patrik Eschle, Thomas Zumbrunn, Christian Sommer, Stephan Scheidegger, Stephen J Ferguson
BACKGROUND: Video fluoroscopy is a technique currently used to retrieve the in vivo three-dimensional kinematics of human joints during activities of daily living. Minimization of the radiation dose absorbed by the subject during the measurement is a priority and has not been thoroughly addressed so far. This issue is critical for the motion analysis of the hip joint, because of the proximity of the gonads. The aims of this study were to determine the x-ray voltage and the irradiation angle that minimize the effective dose and to achieve the best compromise between delivered dose and accuracy in motion retrieval...
May 25, 2017: Journal of Arthroplasty
https://www.readbyqxmd.com/read/28640950/development-of-a-monte-carlo-multiple-source-model-for-inclusion-in-a-dose-calculation-auditing-tool
#8
Austin M Faught, Scott E Davidson, Jonas Fontenot, Stephen F Kry, Carol Etzel, Geoffrey S Ibbott, David S Followill
PURPOSE: The Imaging and Radiation Oncology Core Houston (IROC-H) (formerly the Radiological Physics Center) has reported varying levels of agreement in their anthropomorphic phantom audits. There is reason to believe one source of error in this observed disagreement is the accuracy of the dose calculation algorithms and heterogeneity corrections used. To audit this component of the radiotherapy treatment process an independent dose calculation tool is needed. METHODS: Monte Carlo multiple source models for Elekta 6MV and 10MV therapeutic x-ray beams were commissioned based on measurement of central axis depth dose data for a 10 x 10 cm(2) field size and dose profiles for a 40 x 40 cm(2) field size...
June 22, 2017: Medical Physics
https://www.readbyqxmd.com/read/28640298/ellagitannin-rich-bioactive-extracts-of-tuberaria-lignosa-insights-into-the-radiation-induced-effects-in-the-recovery-of-high-added-value-compounds
#9
José Pinela, M A Prieto, Amilcar L Antonio, Ana Maria Carvalho, M Beatriz P P Oliveira, Lillian Barros, Isabel C F R Ferreira
Ellagitannins are polyphenols responsible for a number of bioactivities and health-promoting effects. These industrially important molecules can be affected by post-harvest treatments and recovery processes, but little is known about the irradiation-induced effects on their integrity, bioactivity and extractability. Herein, the impact of gamma radiation on the production of ellagitannin-rich extracts was investigated using Tuberaria lignosa as a case study. These effects were compared with those induced in flavonoids and organic acids...
June 22, 2017: Food & Function
https://www.readbyqxmd.com/read/28639942/commissioning-of-the-tongue-and-groove-modelling-in-treatment-planning-systems-from-static-fields-to-vmat-treatments
#10
Victor Hernandez, Juan Antonio Vera-Sánchez, Laure Vieillevigne, Jordi Saez
Adequate modelling of the multi-leaf collimator (MLC) by treatment planning systems (TPS) is essential for accurate dose calculations in intensity-modulated radiation-therapy. For this reason modern TPSs incorporate MLC characteristics such as the leaf end curvature, MLC transmission and the tongue-and-groove. However, the modelling of the tongue-and-groove is often neglected during TPS commissioning and it is not known how accurate it is. This study evaluates the dosimetric consequences of the tongue-and-groove effect for two different MLC models using both film dosimetry and ionisation chambers...
June 22, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28639046/is-multidetector-ct-based-bone-mineral-density-and-quantitative-bone-microstructure-assessment-at-the-spine-still-feasible-using-ultra-low-tube-current-and-sparse-sampling
#11
Kai Mei, Felix K Kopp, Rolf Bippus, Thomas Köhler, Benedikt J Schwaiger, Alexandra S Gersing, Andreas Fehringer, Andreas Sauter, Daniela Münzel, Franz Pfeiffer, Ernst J Rummeny, Jan S Kirschke, Peter B Noël, Thomas Baum
OBJECTIVE: Osteoporosis diagnosis using multidetector CT (MDCT) is limited to relatively high radiation exposure. We investigated the effect of simulated ultra-low-dose protocols on in-vivo bone mineral density (BMD) and quantitative trabecular bone assessment. MATERIALS AND METHODS: Institutional review board approval was obtained. Twelve subjects with osteoporotic vertebral fractures and 12 age- and gender-matched controls undergoing routine thoracic and abdominal MDCT were included (average effective dose: 10 mSv)...
June 21, 2017: European Radiology
https://www.readbyqxmd.com/read/28638256/comparison-of-ultrasonography-and-low-dose-computed-tomography-for-the-diagnosis-of-pediatric-urolithiasis-in-the-emergency-department
#12
Recep Sade, Hayri Ogul, Suat Eren, Akin Levent, Mecit Kantarci
OBJECTIVE: This study aimed to compare ultrasonography (US) and low-dose computed tomography (LDCT) for diagnosing pediatric urolithiasis in the emergency department. MATERIALS AND METHODS: This retrospective study was approved by our institutional ethics committee, and informed consent was waived. From March 2016 to March 2017, 100 consecutive patients met the selection criteria and were enrolled in the study. Patients were randomly selected in a 1:1 ratio and were allocated to one of the following two imaging groups: US or abdominal LDCT...
June 2017: Eurasian Journal of Medicine
https://www.readbyqxmd.com/read/28637959/examination-of-dose-reduction-using-image-noise-reduction-technology-in-cardiovascular-x-ray-systems
#13
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/28637483/analyzing-human-decisions-in-igrt-of-head-and-neck-cancer-patients-to-teach-image-registration-algorithms-what-experts-know
#14
Eva Maria Stoiber, Nina Bougatf, Hendrik Teske, Christian Bierstedt, Dieter Oetzel, Jürgen Debus, Rolf Bendl, Kristina Giske
BACKGROUND: In IGRT of deformable head-and-neck anatomy, patient setup corrections are derived by rigid registration methods. In practice, experienced radiation therapists often correct the resulting vectors, thus indicating a different prioritization of alignment of local structures. Purpose of this study is to transfer the knowledge experts apply when correcting the automatically generated result (pre-match) to automated registration. METHODS: Datasets of 25 head-and-neck-cancer patients with daily CBCTs and corresponding approved setup correction vectors were analyzed...
June 21, 2017: Radiation Oncology
https://www.readbyqxmd.com/read/28636805/a-hybrid-phantom-system-for-patient-skin-and-organ-dosimetry-in-fluoroscopically-guided-interventions
#15
David Borrego, Daniel Siragusa, Stephen Balter, Wesley E Bolch
To investigate calibrations for improved estimates of skin dose and to develop software for computing absorbed organ doses for fluoroscopically guided interventions (FGIs) with the use of radiation dose structured reports (RDSR) and the UF/NCI family of hybrid computational phantoms METHODS AND MATERIALS: Institutional review board approval was obtained for this retrospective study in which ten RDSRs were selected for their high cumulative reference air kerma values. Skin doses were computed using the University of Florida's rapid in-clinic peak skin dose algorithm (or UF-RIPSA)...
June 21, 2017: Medical Physics
https://www.readbyqxmd.com/read/28636564/radiation-dosimetry-in-magnetic-fields-with-farmer-type-ionization-chambers-determination-of-magnetic-field-correction-factors-for-different-magnetic-field-strengths-and-field-orientations
#16
Claudia Katharina Spindeldreier, Oliver Schrenk, Anna Bakenecker, Iwan Kawrakow, Lucas Norberto Burigo, Christian P Karger, Steffen Greilich, Asja Pfaffenberger
The aim of this work was to determine magnetic field correction factors that are needed for dosimetry in hybrid devices for MR-guided radiotherapy for Farmer-type ionization chambers for different magnetic field strengths and field orientations. The response of six custom-built Farmer-type chambers irradiated at a 6 MV linac was measured in a water tank positioned in a magnet with magnetic field strengths between 0.0 T and 1.1 T. Chamber axis, beam and magnetic field were perpendicular to each other and both magnetic field directions were investigated...
June 21, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28636511/feasibility-of-low-dose-coronary-computed-tomographic-angiography-used-in-atrial-fibrillation-patients
#17
Chenglin Zhao, Mengxi Jiang, Jianxin Liu, Li Gao, Xiaoying Wang
OBJECTIVE: The diagnosis of coronary artery disease (CAD) in atrial fibrillation (AF) patients using coronary computed tomography angiography (CCTA) requires a large exposure dosage or repeated examinations. This study evaluates the feasibility of using low-dose CCTA in the double prospectively ECG-triggered high-pitch spiral acquisition mode (Double Flash Spiral mode). METHODS: Twenty-eight AF patients with suspected CAD were recruited. Double Flash Spiral mode (tube voltage 100 kVp) and iterative reconstruction was used for CCTA examination...
March 21, 2017: Acta Cardiologica
https://www.readbyqxmd.com/read/28635637/a-short-term-biological-indicator-for-long-term-kidney-damage-after-radionuclide-therapy-in-mice
#18
Giovanni Pellegrini, Klaudia Siwowska, Stephanie Haller, Daniel J Antoine, Roger Schibli, Anja Kipar, Cristina Müller
Folate receptor (FR)-targeted radionuclide therapy using folate radioconjugates is of interest due to the expression of the FR in a variety of tumor types. The high renal accumulation of radiofolates presents, however, a risk of radionephropathy. A potential option to address this challenge would be to use radioprotectants, such as amifostine. Methods for early detection of kidney damage that-in this case-cannot be predicted based on dose estimations, would facilitate the development of novel therapies. The aim of this study was, therefore, to assess potentially changing levels of plasma and urine biomarkers and to determine DNA damage at an early stage after radiofolate application...
June 21, 2017: Pharmaceuticals
https://www.readbyqxmd.com/read/28635617/the-dosimetric-impact-of-gadolinium-based-contrast-media-in-gbm-brain-patient-plans-for-a-mri-linac
#19
Syed Bilal Ahmad, Moti Raj Paudel, Arman Sarfehnia, Anthony Kim, Geordi Pang, Mark Ruschin, Arjun Sahgal, Brian M Keller
Dosimetric effects of gadolinium based contrast media (Gadovist) were evaluated for the Elekta MRI Linear accelerator (MRL) using the research version of Monaco treatment planning system (TPS). In order to represent a gadolinium uptake it was manually assigned to a phantom as well as to the Gross Tumour Volume (GTV) of 6 Glioblastoma Multiforme (GBM) patients. A preliminary estimate of dose enhancement, due to gadolinium, was performed using the phantom irradiated with a single beam. More complicated assessment was performed for the GBM patients using a 7 field IMRT technique...
June 21, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28632195/towards-a-long-term-strategy-for-voluntary-based-internal-radiation-contamination-monitoring-representativeness-of-the-monitoring-results-in-fukushima-japan
#20
Shuhei Nomura, Masaharu Tsubokura, Michio Murakami, Kyoko Ono, Yoshitaka Nishikawa, Tomoyoshi Oikawa
Following Japan's 2011 Fukushima nuclear incident, voluntary participation, rather than mandatory, was adopted as the default scenario for individual radiation monitoring. We evaluated the representativeness of the internal monitoring results from voluntary participants in Minamisoma City, which is located 10-40 km from the Fukushima nuclear plant. Of approximately 70,000 individuals who were residing in Minamisoma City before the incident, a total of 19,263 residents (aged ≥21 years) participated in the monitoring from 1 October 2011 to 31 March 2015...
June 20, 2017: International Journal of Environmental Research and Public Health
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