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Radiation Protection Dosimetry

Masanao Kobayashi, Yasuki Asada, Kosuke Matsubara, Kazuyuki Minami, Shouichi Suzuki, Yuta Matsunaga, Tomonobu Haba, Ai Kawaguchi, Tomihiko Daioku, Hiroshi Toyama, Ryoichi Kato
Swallowing computed tomography (SCT) is a relatively new technique for the morphological and kinematic analyses of swallowing. However, no optimal scan protocols are available till date. We conducted the present SCT study to estimate the patient dose at various patient reclining positions. A RANDO phantom with a thermoluminescent dosemeter was placed on a hard Table board in a semi-reclining position at the centre and off-centre. According to predetermined scan protocols, irradiation was performed to acquire scanograms at reclining angles of 55° and 65°...
June 15, 2017: Radiation Protection Dosimetry
B Cijan, M Mukaj, F Bonutti, E Del Dò, M Floreani, D Kishta, E Martin, M Sponza, Al Mohannadi Salha Saad
Interventional radiology procedures have always been of particular concern because of the potential high dose to the workers. Special attention has recently been given to the lens dose: in 2011 the ICRP issued the recommendation 'Statement on Tissue Reactions' where a new limit of 20 mSv in a year, averaged over defined periods of 5 years, is given. Due to the impossibility of measuring the dose directly on the eye, there is not still a general consensus on a standardized methodology to assess the lens dose, which should be at the same time reliable, robust and simple to implement in practice...
June 8, 2017: Radiation Protection Dosimetry
Carlo Giordano, Ivo Monica, Rossana Gobbi, Lorenzo Barbattini
The aim of this study was to determine the dosimetric parameters of radiation to which orthopedic in-patients are exposed, using data drawn from the hospital's picture archiving and communication system. Data for 310 patients, relating to seven different anatomical districts, were examined. Femoral operations were divided into three types. The 75th percentile dose at the interventional reference point (IRP) exceeded 2 mGy only for femoral interventions (4.6-6.2 mGy) with 75th percentile kerma-area product (KAP) values ranging from 84...
June 8, 2017: Radiation Protection Dosimetry
Hamed Bagheri, Seyed Rabie Mahdavi, Babak Shekarchi, Farhad Manouchehri, Bagher Farhood
This research aimed to measure the received photon and thermal neutron doses to contralateral breast (CB) in breast cancer radiotherapy for various field sizes in presence of physical and dynamic wedges. The measurement of photon and thermal neutron doses was carried out on right breast region of RANDO phantom (as CB) for 18 MV photon beams. The dose measurements were performed by thermoluminescent dosimeter chips. These measurements obtained for various field sizes in presence of physical and dynamic wedges...
June 7, 2017: Radiation Protection Dosimetry
Jaeryong Yoo, Young-Woo Jin, Kwang Pyo Kim
Most internal radiation dose resulting from natural radionuclides is due to radon and radioactive potassium. Total body potassium (TBK) in human body may vary by ethnic group, gender and age. The objective of this study was to measure TBK and body potassium concentration in Korean subjects. Body potassium concentrations of the subjects were measured with a whole-body counter for 283 adult males and 181 adult females. Average TBK value and body potassium level were 111.2 g and 1.5 g kg-1 for males, while for females they were 71...
June 7, 2017: Radiation Protection Dosimetry
Ali B Alhailiy, Patrick C Brennan, Mark F McEntee, Peter L Kench, Elaine A Ryan
Cardiac computed tomography angiography (CCTA) is a commonly used diagnostic tool for cardiovascular disease. Despite constant improvements to imaging technologies, the radiation dose to patients from CCTA remains a concern when using this procedure. There remains a need for optimisation of CCTA procedures and accurate dose monitoring to reduce the potential risk of cancer. Establishing diagnostic reference levels (DRLs) allows for the assessment of radiation dose variations, enabling strategies aimed at standardising doses across radiological centres...
June 7, 2017: Radiation Protection Dosimetry
D Poudel, J A Klumpp, T L Waters, L Bertelli, R A Guilmette
The aim of this study is to present several approaches that have been used to model the behavior of radioactive materials (specifically Pu) in contaminated wounds. We also review some attempts by the health physics community to validate and revise the National Council on Radiation Protection and Measurements (NCRP) 156 biokinetic model for wounds, and present some general recommendations based on the review. Modeling of intake via the wound pathway is complicated because of a large array of wound characteristics (e...
June 7, 2017: Radiation Protection Dosimetry
M Kowatari, H Zutz, O Hupe
In high-energy photon reference fields the value of the air kerma rate is determined by using ionization chambers (ICs). From the charge collected inside the IC the dose can be calculated using a set of calibration and correction factors according to ISO 4037-2. A crucial parameter is the correction for the attenuation and scattering of the primary radiation due to the chamber wall. This parameter can be determined using Monte Carlo calculations. The evaluation of the factor was performed for a commercially available IC of the type Victoreen 550-3 under different build-up conditions...
June 7, 2017: Radiation Protection Dosimetry
Zhen Zhang, Changsong Hou, Dexing Lian, Zhongjian Ma, Junquan Tao, Weiguo Zhu
Some therapeutic proton synchrotron accelerators will be built for cancer treatment in China. The radiation produced by proton must be carefully evaluated and shielded for occupational disease hazard assessment and environmental impact assessment. Adopting the FLUKA code, a therapeutic room model, a synchrotron hall model and a high energy transport line tunnel model are constructed to get the ambient dose equivalent rate distributions. The ambient dose equivalent rates are also calculated with an empirical formula in some regions...
June 7, 2017: Radiation Protection Dosimetry
Hannele Niiniviita, Paulina Salminen, Juha M Grönroos, Irina Rinta-Kiikka, Saija Hurme, Timo Kiljunen, Jarmo Kulmala, Mika Teräs, Suvi Sippola, Johanna Virtanen number, NCT01022567.
June 7, 2017: Radiation Protection Dosimetry
Johannes Boos, Patric Kröpil, Oliver Th Bethge, Joel Aissa, Christoph Schleich, Lino Morris Sawicki, Niklas Heinzler, Gerald Antoch, Christoph Thomas
To evaluate the accuracy of size-specific dose estimate (SSDE) calculation from center slice with water-equivalent diameter (Dw) and effective diameter (Deff). A total of 1812 CT exams (1583 adult and 229 pediatric) were included in this retrospective study. Dw and Deff were automatically calculated for all slices of each scan. SSDEs were calculated with two methods: (1) from the center slice; and (2) from all slices of the volume, which was regarded as the reference standard. Impact of patient weight, height and body mass index (BMI) on SSDE accuracy was assessed...
May 25, 2017: Radiation Protection Dosimetry
James W Marsh, Dominique Laurier, Margot Tirmarche
The International Commission on Radiological Protection (ICRP) has recently published two reports on radon exposure; Publication 115 on lung cancer risks from radon and radon progeny and Publication 126 on radiological protection against radon exposure. A specific graded approach for the control of radon in workplaces is recommended where a dose assessment is required in certain situations. In its forthcoming publication on Occupational Intakes of Radionuclides (OIR) document, Part 3, effective dose coefficients for radon and thoron will be provided...
May 16, 2017: Radiation Protection Dosimetry
Antoine Delmas, Nicolas Weber, Joris Piffre, Cédric Pasquier, Jacques Felblinger, Pierre-André Vuissoz
Worker exposure to electromagnetic fields (EMF) is a growing concern of international commissions. A European directive from 2013 (2013/35/EU) recommend to estimate or measure EMF exposure of all exposed workers. Magnetic resonance imaging (MRI) workers are specially concerned by this point because they work all day long in the vicinity of a very strong magnet (generally 1.5 or 3 T), which cannot be turned off. Setting up a magnetic field monitoring device on these workers would therefore be a good way to ensure their security...
May 12, 2017: Radiation Protection Dosimetry
Masoumeh Parsi, Mehdi Sohrabi, Fereidoun Mianji, Reza Paydar
The purpose of this study was to evaluate the effects of the gantry angulation on dose profiles along the z-axis, the CTDIW value and the CTDIW efficiency in the head examinations. A Monte Carlo simulation model of a GE LightSpeed 16-slice CT scanner was developed by a GATE toolkit. The CTDI100 in air at the isocenter and in a head dosimetry phantom were measured using a pencil ion chamber. Dose profiles were studied in the central and peripheral holes of the head phantom using thermoluminescence LiF disc dosemeters for gantry angulations of 0°, 10° and 20°...
May 12, 2017: Radiation Protection Dosimetry
Lukáš Kotík, Vera Becková, Irena Malátová, Ladislav Tomasek
The aim of the study is to make a comparison of daily 238U excretion in urine among 115 active uranium miners and its modeled values obtained from inhalation intake of long-lived alpha emitters as measured by personal dosemeters and assessed by biokinetic models for different absorption parameters settings for inhaled uranium. A total of 144 spot samples of urine were collected. The 238U content was measured using high-resolution inductively coupled plasma mass spectrometry method. To obtain estimates of the daily excreted values, the daily values were calculated according to the expected daily excretion of creatinine assessed individually for each miner...
May 12, 2017: Radiation Protection Dosimetry
Fuminobu Sato, Tatsuro Maekawa, Tomoharu Kariba, Sachie Kusaka, Teruya Tanaka, Isao Murata
A novel optically stimulated luminescence (OSL) detector containing isotopically enriched boron was developed for thermal neutron dosimetry. Alumina containing isotopically enriched boron (Al2O3:B) was synthesised by the sol-gel method. The Al2O3:B was annealed up to ~1800 K. For X-ray diffractometer (XRD) analysis, the diffraction pattern of the Al2O3:B had reflex peaks corresponding to α-Al2O3. The sensitivity of Al2O3:B to photons was slightly 2% of that of a commercial Al2O3:C. The Al2O3:B detector had satisfactory linearity in X-ray dose measurement...
May 12, 2017: Radiation Protection Dosimetry
Tania Berlana, Alejandro Úbeda
Occupational exposure to static and radiofrequency fields emitted by nuclear magnetic resonance spectrometers was assessed through systematic field metering during operation of 19 devices in nine research centers. Whereas no measurable levels of radiofrequency radiation were registered outside the spectrometers, significant exposure to static field was detected, with maximum values recorded at the user's hand (B = 683.00 mT) and head-thorax (B = 135.70 mT) during spectrometer manipulation. All values were well below the exposure limits set by the European standard for workers protection against the effects of acute field exposure only...
May 4, 2017: Radiation Protection Dosimetry
Yaping Qi, Lijuan He, Zhi Wang, Yuanyuan Liu, Hongdong Liu, Wanli Huo, X George Xu, Zhi Chen
There have been few studies on the secondary cancer after radiation treatment in Chinese hospitals. This study has measured out-of-field absorbed organ doses from intensity-modulated radiation therapy (IMRT) radiotherapy for esophageal cancer in a Chinese hospital and evaluated the risks of secondary cancer. The dose measurements were based on the thermo-luminescence dosemeter (TLD) and the ATOM® phantom, which represents an adult male. Over 100 TLD chips were placed in 35 different organ sites and one group of the same TLDs was set as background contrast...
May 3, 2017: Radiation Protection Dosimetry
Erik Poenitz, Clemens Walther
In several countries, the high-level radioactive waste that will be disposed of in deep geological formations has to be retrievable for a certain time. Since 2010, retrievability is required for the operation phase of a repository also in Germany. Depending on the effort and the feasibility of remote handling, a certain exposure of the involved employees to ionising radiation is caused. The estimation of the exposure requires the knowledge of the inventory of radionuclides and the radiation field around the storage containers...
May 2, 2017: Radiation Protection Dosimetry
Manish K Sahai, S M Pradhan, A K Bakshi, D Datta
Thermoluminescence (TL) signal obtained during second readout of a TL dosemeter disc previously exposed to ionising radiation is termed as residual TL. The origin of residual TL has not been discussed in detail so far in the literature. In this work, experimentally obtained residual TL signal and its origin is studied for CaSO4:Dy-based TL dosemeter through numerical simulation and role of deeper traps has been discussed.
April 27, 2017: Radiation Protection Dosimetry
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