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Interventional professionals tend to receive extended radiation exposure given the complexity and machine settings of procedures in interventional cardiology departments, resulting in a high eye lens dose. This study developed a method for estimating the occupational radiation dose to the eye lens based on the personal dose equivalent to the skin at 0.07-mm depth [ H p (0.07)] obtained using an over-apron dose badge, investigated whether glasses with lateral shielding but a thin Pb-equivalent material could adequately protect the eye lens from radiation in clinical situations, and identified factors affecting the occupational radiation dose to the eye lens. The occupational radiation dose was prospectively measured using dosimeters near the eye and over the lead apron at the collar level in 26 interventional professionals performing 444 procedures in interventional cardiology departments. Type A (0.07-mm front and lateral Pb equivalence) and type B (0.5-mm front Pb equivalence and 0.25-mm lateral Pb equivalence) glasses were worn by the operators during operation to protect the eye lens. The median personal dose equivalent to the eye lens at 3-mm depth [ H p (3)/dose area product (DAP)] of the primary operator was the highest (7.6 μSv/Gycm2) for upper limb percutaneous transluminal angioplasty among all examined procedures. The secondary operator's median H p (3)/DAP values ranged from 17% to 41% of that of the primary operator. The median H p (3)/DAP values did not significantly differ between the primary operators wearing type A glasses and those wearing type B glasses for percutaneous coronary intervention or diagnostic cardiology studies (all p > 0.05). The Pearson correlation test results revealed significant positive correlations between the H p (3) and H p (0.07). The estimated annual H p (3) values ranged from 3.3 ± 0.6 to 62.4 ± 8.3 mSv and from 6.0 to 8.0 ± 4.6 mSv for the cardiologists and radiographers, respectively. The H p (3) value can be estimated from the H p (0.07) value obtained using an over-apron dose badge at the collar level. Glasses with 0.07-mm front and lateral Pb equivalence provide satisfactory radiation protection to the eye lens. Regularly using appropriate radiation-protective lead glasses, adopting small angles for left anterior oblique projections, and undertaking moderate workloads are highly recommended to prevent cardiologists from receiving excessive radiation doses to the eye lens. • Lead glasses with proper design and lighter weight were recommended. • Factors affecting the H p (3) values were identified. • A model for estimating H p (3) from the H p (0.07) value was developed. • Strategies of radiation protection to the eye lens were proposed. [ABSTRACT FROM AUTHOR]

This paper presents the first experimental result for scatter dose at the height of the operator's eye measured for a Polymethyl methacrylate (PMMA) phantom simulating an adult patient in an interventional laboratory at Belo Horizonte, Brazil. Values for scattered radiation doses at the height of the operator's eye are reported for procedures performed with and without a ceiling-suspended screen. Correlations between scatter radiation doses and different angiographic projections, phantom entrance dose and kerma area product, were obtained. Experimental measurements were made in an angiography X-ray system equipped with flat-panel detector. A cine and three fluoroscopy modes: low, medium and high dose were available. Scattered radiation doses were measured at three angiographic projections: anterior-posterior (AP), left anterior oblique 90° and left anterior oblique 45° with cranial 30° (spider) angulations. The detector measuring scatter radiation was positioned at the usual distance of the cardiologist's eye and the detector measuring phantom entrance dose was positioned at the bottom of the PMMA phantom. The phantom entrance dose for fluoroscopy low, medium, high and cine were 15, 29, 36 ± 4 and 184 ± 18 mGy/min, respectively to AP projection. A good linear correlation exists between phantom entrance doses rate and scatter dose rate to AP projection. There is a good linear correlation between the kerma-area product and scatter dose at the height of the operator's eye, coefficient of determination R 2 were 0.9728 and 0.9913 with and without ceiling-suspended screen. An experimental correlation factor of 0.1 and 3.5 μSv/Gy*cm2 has been found for the AP projection with and without ceiling-suspended screen, respectively. Scatter dose at the eyes cardiologist position depends on the C-arm angulation an increase of the scatter radiation dose by a factor of 5 was found. The highest dose rate in the lens was 19.74 ± 1.97 mSv/h without ceiling-suspended screen in cine mode for “spider” projection. For lateral projection in cine mode, the ceiling-suspended screen reduced dose by a factor 0.01. Interventional operator may therefore easily exceed the lens dose limit if ceiling-suspended screen is not used. [ABSTRACT FROM AUTHOR]

Precise knowledge of the energy response of radiation detector materials is necessary for accurate dose measurements, because the usual TL and OSL material response relative to the medium of interest (air, water or tissue) varies with beam energy. In this work, we experimentally evaluated the photon energy dependence of different materials used as detectors (Al 2 O 3 :C – Luxel, BeO – Thermalox 995, LiF:Mg,Ti – TLD100 and Brazilian pellets based on CaSO 4 :Dy and CaF 2 :natural) in personal dosimetry through OSL and TL techniques, using optimized readout parameters for each material and radiation qualities similar to real situations of exposure. It is well known that depending on the material's effective atomic number and type of stimulation, the photon energy response can present either an under-response relative to air in the low energy range, as is the case of BeO, or a large over-response, as Al 2 O 3 , CaSO 4 and CaF 2 , or even a very flat-response, as LiF. By utilizing intrinsic characteristics of these materials combined with OSL and TL techniques, we evaluated ratios of relative photon energy responses between pairs of OSL (OSLD) and TL (TLD) detectors. We have noted that for all combinations of materials (Al 2 O 3 /LiF, CaSO 4 /BeO, and CaF 2 /BeO), the ratio of energy responses of each pair did not change significantly with energy in the intervals below 50 or above 300 keV. On the other hand, in the range of energies between 50 and 300 keV, there was a strong change in the ratio values, indicating that the ratio of detector responses well-discriminates the incident photon energy. By using these outcomes, it was possible to apply dose corrections with respect to energy using ratios of OSL and TL signals of dosimeters exposed to unknown radiation beam qualities and to determine doses in a blind test. Our results point out that this methodology could be employed to correct photon energy responses of a personal dosimeter based on both OSL and TL techniques. OSL advantages (fast readout, possibility of various partial readings and of determining accumulated doses) would be associated with the TL ones (large variety of dosimeters commercially available and use of glow curve as a readout quality control) in a dual detector system capable of determining photon energy and dose, without using attenuation filters. This new methodology might improve dose evaluation in personal dosimetry. [ABSTRACT FROM AUTHOR]

Abstract: The thermoluminescent (TLD) method is one of the most commonly used in dose measurements in radiation protection dosimetry. Due to its many advantages this method is widely spread. However, TLD has especially one disadvantage which is very inconvenient: the dose information in already read detectors is erased and in routine standard way the dose can not be reassessed. The positive is that this shortcoming can be eliminated by applying UV radiation. After first readout the same detector can be subjected to UV exposure and then read once again to reassess the dose. This method for reassessment of dose is based on phototransferred thermoluminescence (PTTL). In an irradiated TL detector deep traps are not emptied during the first readout. During exposure to UV, electrons are transferred from deep traps to shallower dosimetric traps. This TL signal emerging during the second readout following UV illumination is called phototransferred thermoluminescence. A method for reassessment of dose in a previously readout TLD is presented in this work. Experiments show that the method works well within region of doses between 5 and 50 mGy, but could be applied for higher doses as well. The efficiency of dose reassessment reaches about 17 percent of the first readout. The method could be a noticeable improvement in TLD dosimetry, giving more opportunities for better control and reliability of measurements. [Copyright &y& Elsevier]

Abstract: This paper reviews the revised Technical Recommendations for Monitoring Individuals Occupationally Exposed to External Radiation as issued by the European Commission as Radiation Protection 160. These recommendations are aimed at all stakeholders in radiation protection dosimetry with an emphasis in the responsible technical staff of approved dosimetry services. This paper briefly touches each Chapter and ends with a more in depth section on the uncertainty evaluation of dose measurements. [Copyright &y& Elsevier]

Abstract: The main aim of the Work Package 1 (WP1) of the ORAMED project, Collaborative Project (2008–2011), supported by the European Commission within its 7th Framework Programme, was to obtain a set of standardized data on extremity and eye lens doses for staff in interventional radiology and cardiology (IR/IC) workplaces and to recommend a series of guidelines on radiation protection in order to both guarantee and optimize staff protection. Within the project, coordinated measurements were performed in 34 hospitals in 6 European countries. Furthermore, simulations of the most representative workplaces in IR and IC were performed to determine the main parameters that influence the extremity and eye lens doses. The work presented in this paper shows the recommendations that were formulated by the results obtained from both measurements and simulations. The presented guidelines are directed to operators, assistant personnel, radiation protection officers and medical physics experts. They concern radiation protection issues, such as the use of room protective equipment, as well as the positioning of the extremity and eye lens dosemeters for routine monitoring. [Copyright &y& Elsevier]

Abstract: In its capacity as the supervisory authority, the Swiss Federal Office of Public Health (SFOPH) has responded to the increase in extremity doses observed in nuclear medicine facilities in Switzerland over the past decade by introducing facility-specific radiation protection audits. These audits have raised the awareness of the staff members concerned with the problem of high extremity doses which arise from handling beta emitters and PET nuclides and prevented any further rise in the extremity doses. However, the evaluation of these audits has also shown that there is still considerable scope for improvement in terms of reducing extremity doses and that further measures are therefore required. Facility-specific and person-specific investigations are currently being conducted with the support of the SFOPH. Their aim is to show facilities which operations during the preparation and application of diagnostic and therapeutic radiopharmaceuticals lead to high extremity doses. This will enable the reduction of extremity doses for nuclear medicine staff as well as ensure that the dose limits are adhered to, in spite of the increasing numbers of examinations. [Copyright &y& Elsevier]

Abstract: To evaluate and optimise extremity doses in nuclear medicine, work package 4 of the ORAMED project () focussed on investigating skin doses of nuclear medicine worker hands (). In addition to a measurement campaign, selected scenarios were simulated by means of hand wax phantoms. The phantoms were modelled according to the scenario of radiopharmaceutical syringe handling. The wax phantoms in the position of interest were scanned and introduced as lattice (voxel) geometry into the simulation input geometry. In this article the mathematical articulated hand model developed at KIT () is compared to these models. This mathematical hand phantom consists of rigid and flexible elements, allowing for an adaptable anatomy and flexible hand poses. In contrast to the static voxel models obtained by a complex procedure based on CT-scanned images, the articulated hand phantom can be used comparably simply for differing scenarios. [Copyright &y& Elsevier]

Abstract: Radiation exposure for the staff in nuclear medicine departments is inevitable. After application of radiopharmaceuticals the patient himself becomes a radioactive source. Consequently, we need detailed information on the extent of radiation exposure for each single person dealing with radioactive sources and patients in nuclear medicine. In this work, dose rates of a variety of radioactive sources – radiopharmaceuticals and patients – in nuclear medicine were investigated. For this purpose different detectors (dosimeters, survey-meters) were used and different sources were measured for several distances between source and detector. The “radioactive patient” as a source can be considered as uncritical. However, this assumption only holds if members of the personnel keep a sufficient distance to the patient of at least 1 m. If treatments in the vicinity of the patient become necessary, the time spent in a closer distance should be limited. The handling of radiopharmaceuticals often involves close contact to the radioactive source. For the β-radiation or in the mixed β,γ-radiation field of several high energy beta emitters (32P, 68Ga, 90Y, 188Re) the ambient dose equivalent rate at 10 mm depth together with the directional dose equivalent rate at 0° and 0.07 mm depth have to be determined. Especially for the beta emitters mentioned above these dose rates are very high. For instance the specific dose rate for 90Y yields 4.6 Sv/(GBq∙h) when dose rate measurements were performed in the closest distance to a glass vial that was practicable. Survey-meters that are only capable of measuring photons fail to provide even a rough approximation of the actual dose rate. Preparations of radiopharmaceuticals with these nuclides may consequently cause a high extremity exposure of laboratory staff. This requires measurements, demands training and a strict compliance with the established radiation safety standards. [Copyright &y& Elsevier]

Abstract: We performed individual dose measurements, in terms of Hp(10) for the whole body, Hp(0,07) for the extremities (hands) and Hp(3) for the eyes, for medical personnel (technical staff, nurses and medical doctors) in three nuclear medicine departments. One conventional diagnostic scintigraphy department, where Tc-99m, I-131 and Sm-153 were applied, and two PET-CT departments where F-18 was applied in preparation and application procedures, were studied. A novel eye lens dosemeter was used, designed to evaluate Hp(3) directly. From our measurements we obtained ratios of Hp(3)/Hp(10) ranging between 0.7 and 1.1 indicating that in nuclear medicine procedures eye lens doses could probably be estimated from Hp(10) values and that exceeding the present annual dose limit to eye lens (150 mSv) is very unlikely. The relationship between different individual doses can indicate the quality of radiation protection in a nuclear medicine department. [Copyright &y& Elsevier]

Abstract: Workers performing preparation and administration of radiopharmaceuticals in NM departments are likely to receive high local skin doses to the hands which may even surpass the dose limit of 500 mSv whenever radiation protection standards are insufficient. A large measurement campaign was organised within the framework of the ORAMED project to determine the dose distribution across the hands received during preparation and administration of 18F- and 99mTc-labelled radiopharmaceuticals. The final data, collected over almost 3 years, include 641 measurements from 96 workers in 30 NM departments from 6 European countries. Results have provided levels of reference doses for the considered standard NM diagnostic procedures (mean maximum normalised skin dose of 230 μSv/GBq, 430 μSv/GBq, 930 μSv/GBq and 1200 μSv/GBq for the administration of 99mTc, preparation of 99mTc, administration of 18F and preparation of 18F, respectively). Finger dose was analysed as a function of the potential parameters of influence showing that shielding is the most efficient means of radiation protection to reduce skin dose. An appropriate method for routine monitoring of the extremities is also proposed: the base of the index finger of the non-dominant hand is a suitable position to place the ring dosemeter, with its sensitive part oriented towards the palm side; its reading may be multiplied by a factor of 6 to estimate the maximum local skin dose. Finally, results were compared to earlier published data, which correspond mostly to individual works with a reduced number of workers and measurements. [Copyright &y& Elsevier]

Abstract: Occupational dosimetry is still a challenge in fluoroscopy-guided procedures. Personal dosimeters are not regularly used by many professionals. Most of the dosimeters used are worn under the lead apron and it is difficult to estimate radiation doses to the unprotected organs and tissues. New electronic dosimeters make it possible to know staff doses and dose rates in real time, inside interventional laboratories. A system using solid-state detectors and equipped with a wireless connection (DoseAware distributed by Philips) that sends the scatter dose rate and cumulative scatter dose readings to a base station, inside the catheterization room, has been evaluated. The initial test was carried out over a period of 4 months in two laboratories (a cardiology one and a second one dedicated to general interventional procedures). In addition to the educational value of the dosimetry system, other benefits have been identified such as the detailed information on occupational dose rate during the procedures, the possibility of comparing occupational doses registered among different staff during the procedures, the capability of establishing correlations between occupational and patient doses, and correlations between staff doses and geometry and radiographic factors used during the procedures. From all this information, it is possible to derive criteria for optimization of occupational radiation protection. [Copyright &y& Elsevier]

Abstract: Within the ORAMED project (Optimization of Radiation Protection of Medical Staff) a coordinated measurement program for occupationally exposed medical staff was performed in different hospitals in Europe (www.oramed-fp7.eu). The main objective was to obtain a set of standardized data on extremity and eye lens doses for staff involved in interventional radiology and cardiology and to optimize radiation protection. Special attention was given to the measurement of the doses to the eye lenses. In this paper an overview will be given of the measured eye lens doses and the main influence factors for these doses. The measured eye lens doses are extrapolated to annual doses. The extrapolations showed that monitoring of the eye lens should be performed on routine basis. [Copyright &y& Elsevier]

Abstract: The Interventional Radiology (IR) is a well established technique in medical domain aiming to obtain a good X-ray image quality while minimizing the radiation dose absorbed by patients and staff members. From a radioprotection point of view, these procedures are considered potentially harmful for interventional radiologists and medical staff. Individual monitoring of operators is very important and is performed by assessing effective dose, equivalent dose to the extremities and eye lens, with the use of passive dosimeters (e.g. TLDs) calibrated in terms of personal dose equivalent Hp (10), Hp (0.07) and Hp (3), respectively. In this work we will present a proposal for an innovative X-ray dosimeter prototype, capable of real-time measurements, packaged in a small form-factor, with wireless communication to be used for individual operators dosimetry during IR procedures. The proposed real-time dosimeter relies on CMOS Active Pixel Sensor, widely used in visible imaging applications. Some preliminary results on the characterization of CMOS active pixel sensors as diffused X-ray detectors during a typical IR session will be presented. [Copyright &y& Elsevier]

Abstract: This study focuses on the occupational doses of technologists working at an Animal Research Unit using PET radiotracers and on the environmental dose rates produced by the animals (mice, rats and monkeys). In particular, whole body and extremity monitoring is reported and related with the workload. The study shows that doses not only depend on the amount of activity injected but also on the type of animals and radiotracers managed. The extremities, with a great variability of the doses received, are the limiting organs as far as regulatory dose limits for workers are concerned. Mean H∗(10) rates in contact and at 20 cm from the animals, when they are handled by the technologist, range from around 1 mSv/h to 20 μSv/h, respectively. [Copyright &y& Elsevier]

Abstract: Radiation protection training and education is important in stimulating safety culture of occupationally exposed workers. Taking into account the mandatory requirements in relation to education and training a digital training tool was introduced for communication of personal dose results and regular information on radiation protection. This tool enables that personal dose reports are monthly sent to the individual mailbox of workers together with short comprehensive slideshows on radiation protection topics. After two years of operational practice a survey was organised to evaluate the training tool. The results show that the majority (92%) of the occupationally exposed workers are aware of the communication of personal dose results through e-mail. Furthermore, 81% of these workers are also aware of their monthly and cumulated dose level. The monthly information on radiation protection topics is however less consulted. Around 40% of the workers that noticed the link are indifferent to the monthly information. The interest in radiation protection issues increases however with the education level. [Copyright &y& Elsevier]