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Radiation Protection Dosimetry

B A Napier
The reconstruction of radiation doses to Mayak Production Association workers in central Russia supports radiation epidemiological studies for the U.S.-Russian Joint Coordinating Committee on Radiation Effects Research. The most recent version of the dosimetry was performed with the Mayak Worker Dosimetry System-2013. This introduction outlines the logic and general content of the series of articles presented in this issue of Radiation Protection Dosimetry. The articles summarize the models, describe the basis for most of the key decisions made in developing the models and present an overview of the results...
March 17, 2017: Radiation Protection Dosimetry
M W Oliveira da Silva, L V Canevaro, J Hunt, B B D Rodrigues
Interventional cardiology requires complex procedures and can result in high doses and dose rates to the patient and medical staff. The many variables that influence the dose to the patient and staff include the beam position and angle, beam size, kVp, filtration, kerma-area product and focus-skin distance. A number of studies using the Monte Carlo method have been undertaken to obtain prospective dose assessments. In this paper, detailed irradiation scenarios were simulated mathematically and the resulting dose estimates were compared with real measurements made previously under very similar irradiation conditions and geometries...
March 16, 2017: Radiation Protection Dosimetry
A Moslehi, G Raisali
To determine the dose-equivalent of neutrons in an extended energy range, in the present work a multi-element thick gas electron multiplier-based microdosemeter made of PMMA (Perspex) walls of 10 mm in thickness is designed. Each cavity is filled with the propane-based tissue-equivalent (TE) gas simulating 1 µm of tissue. Also, a few weight fractions of 3He are assumed to be added to the TE gas. The dose-equivalents are determined for 11 neutron energies between thermal and 14 MeV using the lineal energy distributions calculated by Geant4 simulation toolkit and also the lineal energy-based quality factors...
March 14, 2017: Radiation Protection Dosimetry
M Borg, A Konstantinidis
The aim of this study is to explore the use of a quality (Q) factor in digital mammography as a figure-of-merit. Q factors take a reference value into account and can be compared to a theoretical value. They are also intended to summarise the performance of any unit based on a number. The mean glandular dose (MGD)-normalised Q factors were also introduced based on the relationship of the Q factors with MGD. Interestingly, the automatic exposure control exposures did not render the maximum normalised Q factor values as expected, which could indicate the need for further optimisation...
March 14, 2017: Radiation Protection Dosimetry
Jae Won Yun, Eun Shil Cha, Seulki Ko, Won Jin Lee
This study investigated occupational characteristics and radiation exposure among radiologic technologists assisting fluoroscopically guided interventional (FGI) procedures. A nationwide survey of radiologic technologists in South Korea was conducted. Among 8058 male respondents, 664 (8.2%) assisted FGI procedures. The survey data were linked with dosimetry data from the National Dose Registry. Most radiologic technologists assisting FGI procedures were 30-40 years old and employed by general hospitals. These technologists worked in closer proximity to patients during procedures, less frequently used shield screens, more commonly utilized protective devices, and less commonly wore badge dosemeters than the ones not assisting FGI procedures...
March 3, 2017: Radiation Protection Dosimetry
Herkko Pirkkalainen, Timo Heiskanen, Juhani Tonteri, Jarmo Elovaara, Penttilä Mika, Leena Korpinen
Earlier studies conducted at 400 and 110 kV substations in Finland have shown that the occupational exposure to electric fields can exceed the action levels (ALs) set by Directive 2013/35/EU. This is a case study investigating the level of occupational exposure experienced by workers at 220 kV substations in order to determine if the actions levels are being exceeded. The measurements were conducted at two old 220 kV substations in Finland. The higher AL of 20 kV m-1 was exceeded at both substations.
March 3, 2017: Radiation Protection Dosimetry
Makoto Hirata, Hajime Monzen, Kohei Hanaoka, Yasumasa Nishimura
The absorption dose outside the irradiation field for prostate intensity-modulated radiation therapy was measured and evaluated by comparison with calculated values of radiation treatment planning system (TPS). The values of TPS calculated were using Varian CLINAC21EX/Eclipse and TomoTherapy Planning System for constant irradiation time. The absorption dose was measured by placing a glass-element dosemeter in a human-bone enclosure phantom with a planning target volume inside the irradiation field. The organs at risk were the rectum, spinal cord, thyroid, eyeball and the left lung...
March 3, 2017: Radiation Protection Dosimetry
Adnan Lahham, Afifeh Sharabati, Hussein ALMasri
A total of 271 measurements were conducted at 69 different sites including homes, hospitals, educational institutions and other public places to assess the exposure to radiofrequency emission from wireless local area networks (WLANs). Measurements were conducted at different distances from 40 to 10 m from the access points (APs) in real life conditions using Narda SRM-3000 selective radiation meter. Three measurements modes were considered at 1 m distance from the AP which are transmit mode, idle mode, and from the client card (laptop computer)...
March 3, 2017: Radiation Protection Dosimetry
Nataša Todorovic, Dušan Mrda, Jan Hansman, Slavko Todorovic, Jovana Nikolov, Miodrag Krmar
Studies have been carried out to determine the natural radioactivity in some materials used in ceramic industry (zircon, zirkosil, Zircobit MO/S, zircon silicate, zirklonil frit, hematite, bentonite, wollastonite, raw kaolin, kaolinized granite, sileks ball, feldspar, pigment, white base serigraphic, engobe) and their associated radiation hazard. The external hazard index, Hex, values, radium equivalent activity, Raeq, total absorbed dose rates, D and annual effective dose, De were derived for all measured materials and compared with the recommended values to assess the external radiation hazards to workers who worked in ceramic industries in Serbia...
March 3, 2017: Radiation Protection Dosimetry
Kshama Srivastava, Seepika Soin, B K Sapra, P Ratna, D Datta
The occupational exposure incurred by the radiation workers due to the external radiation is estimated using personal dosemeter placed on the human body during the monitoring period. In certain situations, it is required to determine whether the dosemeter alone was exposed accidentally/intentionally in radiation field (static exposure) or was exposed while being worn by a worker moving in his workplace (dynamic exposure). The present thermoluminscent (TL) based personnel monitoring systems are not capable of distinguishing between the above stated (static and dynamic) exposure conditions...
March 2, 2017: Radiation Protection Dosimetry
Dale L Preston, Daniel O Stram
There has been a long process of growth and development of statistical approaches to the analysis of cancer incidence and mortality data obtained from the follow-up of radiation exposed populations. The challenges of radiation risk analysis provided impetus for innovative statistical methods, including, the inception and continued improvement of hazard rate regression methods. Key statistical contributions that improved cancer risk estimation include statistical advances pertaining to the measurement error problem...
March 2, 2017: Radiation Protection Dosimetry
Dogan Yasar, Enis Kapdan, Muharrem Korkmaz
The Active personal dosemeter (APD) developed by Çekmece Nuclear Research and Training Center/Nuclear Electronic Laboratory (ÇNRTC/NEL) was calibrated at the reference radiation quality (137Cs). The performance tests were carried out with 137Cs, 60Co and X-ray beam qualities in compliance with the standards of International Organization for Standardization ISO4037-1,3 and The International Electrotechnical Commission, IEC61526:2010. Response of the personal dose equivalent was observed to be within the range from -7...
March 1, 2017: Radiation Protection Dosimetry
Amir Hakimi, Mehdi Sohrabi, Seied Rabie Mahdavi
Photoneutron (PN) dosimetry studies in high-energy X-ray medical accelerators are of high clinical and scientific interest in particular to protect patients undergoing radiotherapy. In this context, fast, epithermal and thermal PN dose equivalent distributions in different field sizes and depths in air and in a multilayer polyethylene phantom were studied. Polycarbonate track dosemeters in contact with a 10B convertor (with or without cadmium cover) when electrochemically etched were applied. PN dose equivalents in air and on the surface of the phantom are linear functions of field size...
March 1, 2017: Radiation Protection Dosimetry
L Bourgois, S Ménard, N Comte
Values of the new protection quantity 'Local Skin Dose' LSD, introduced by the International Commission on Radiological Protection (ICRP) Publication 116, were calculated for 134 β- or β+ emitting radionuclides, using the Monte Carlo code MCNP6. Two types of source geometry are considered: a point source and disc-type surface contamination (the source is placed in contact with the skin). This new protection quantity is compared with the operational quantity H'(0.07,0°), leading us to conclude that, in accordance with the rules of the ICRP, the operational quantity over-estimates the protection quantity to a reasonable extent, except in very rare cases for very low average beta energies...
March 1, 2017: Radiation Protection Dosimetry
Yuta Matsunaga, Ai Kawaguchi, Kenichi Kobayashi, Masanao Kobayashi, Yasuki Asada, Kazuyuki Minami, Shoichi Suzuki, Koichi Chida
We investigated changes in the entrance skin dose (ESD) and the mean glandular dose (MGD) during plain radiography or mammography in Japan from 1974 to 2014. Surveys regarding the conditions used for plain radiography and mammography were performed throughout Japan in 1974, 1979, 1989, 1993, 1997, 2001, 2003, 2007, 2011 and 2014. The anatomical regions considered were categorised as follows: skull anteroposterior (AP), lumbar AP, lumbar lateral (LAT), pelvis (AP), ankle, chest posteroanterior (PA), Guthmann (lateral pelviography for pregnant women), infant hip joint and mammography...
March 1, 2017: Radiation Protection Dosimetry
Marija Majer, Liliana Stolarczyk, Marijke De Saint-Hubert, Damian Kabat, Željka Kneževic, Saveta Miljanic, Natalia Mojzeszek, Roger Harrison
The purpose of this study was to measure out-of-field organ doses in clinical conditions in anthropomorphic paediatric phantoms which received a simulated treatment of a brain tumour with intensity modulated radiotherapy (IMRT) and 3D conformal radiotherapy (3D CRT). Organ doses measured with radiophotoluminescent and thermoluminescent dosemeters were on average 1.6 and 3.0 times higher for the 5 y-old than for the 10 y-old phantom for IMRT and 3D CRT, respectively. A larger 5-y to 10-y organ dose ratio for 3D CRT can be explained because the use of a mechanical wedge for the 5-y-old 3D CRT phantom treatment increased out-of-field doses...
February 27, 2017: Radiation Protection Dosimetry
David Welch, Gerhard Randers-Pehrson, Henry M Spotnitz, David J Brenner
Measurement of ultraviolet (UV) radiation is important for human health, especially with the expanded usage of short wavelength UV for sterilization purposes. This work examines unlaminated Gafchromic EBT3 film for UV radiation monitoring. The authors exposed the film to select wavelengths in the UV spectrum, ranging from 207 to 328 nm, and measured the change in optical density. The response of the film is wavelength dependent, and of the wavelengths tested, the film was most sensitive to 254 nm light, with measurable values as low as 10 µJ/cm2...
February 27, 2017: Radiation Protection Dosimetry
T Olgar, T Sahmaran
Pediatric patients are more sensitive to ionizing radiation when compared with adults. The aim of this study was to evaluate the radiation doses for some common pediatric x-ray examinations performed with various digital radiography systems. Quality control tests of the digital radiography systems were carried out according to international published protocols before the pediatric dose measurements. Radiation dose measurement was performed by using the x-ray tube outputs and thermoluminescent dosimeter dose measurement methods...
February 25, 2017: Radiation Protection Dosimetry
Masahiko Toyota, Yasumasa Saigo, Kenta Higuchi, Takuya Fujimura, Chihaya Koriyama, Takashi Yoshiura, Suminori Akiba
Intensity-modulated radiation therapy (IMRT) can deliver high and homogeneous doses to the target area while limiting doses to organs at risk. We used a pediatric phantom to simulate the treatment of a head and neck tumor in a child. The peripheral doses were examined for three different IMRT techniques [dynamic multileaf collimator (DMLC), segmental multileaf collimator (SMLC) and volumetric modulated arc therapy (VMAT)]. Peripheral doses were evaluated taking thyroid, breast, ovary and testis as the points of interest...
February 25, 2017: Radiation Protection Dosimetry
Reza Aminzadeh, Arno Thielens, Haolin Li, Carole Leduc, Maxim Zhadobov, Guy Torfs, Johan Bauwelinck, Luc Martens, Wout Joseph
For the first time, a personal exposimeter (PEX) for 60 GHz radiation measurements is presented. The PEX is designed based on numerical simulations and both on-body and on-phantom calibration measurements to determine the antenna aperture and measurement uncertainty of the PEX. The measurement uncertainty of the PEX is quantified in terms of 50 and 95% prediction intervals of its response. A PEX consisting of three nodes (antennas) with VHH (vertical-horizontal-horizontal) polarization results in a 95% prediction interval of 6...
February 25, 2017: Radiation Protection Dosimetry
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