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Over the last 10 years there have been increasing concerns raised about a potential skills gap in the field of radiation protection (RP). Noting these concerns in 2019, the Society for Radiological Protection, the UK's Chartered Professional Body, launched a study to determine the RP demand in the UK going forward along with the capacity of the profession. The initial results show that over 50% of the SRP membership retires in the next 10−15 years, coupled with an increase in RP demand across the nuclear fuel cycle, medical sector and advancement of new technologies or applications requiring RP advice. This provides strong evidence supporting the concerns of a future skills gap. This paper presents a framework highlighting three core objectives that need to be met to resolve the skills gap. A review of the existing initiatives being undertaken by the Society of Radiological Protection to meet these objectives is included, identifying both areas of good practice and areas for further work and development. A key theme in tackling this challenge has been identified as the need to foster greater collaboration between RP professionals, and organizations both within the UK and abroad, such as IRPA, national societies, employers, academia and industry. This brings a unique opportunity to direct efforts and resources toward a common goal, allowing the sharing of good practice, whilst reducing the strain and burden on any one organization. Another key output of the review was the need to embrace new and innovative solutions to developing our profession and importantly inspiring and communicating into the future of the profession.

An enormous amount of environmental monitoring data has been acquired by various organisations for the evaluation and implementation of countermeasures to mitigate the effects of the accident at the Fukushima Daiichi Nuclear Power Plant. However, it is difficult to collate, compare, and analyse this data because it was published in different formats at different sites according to the respective objectives of the publishing organisations. Moreover, these organisations have been accumulating data in large volumes for over nine years after the accident. We established procedures to collect this data, convert them into a unified format, classify them according to categories, and make the data accessible on a web-based database system. The database contains environmental monitoring data on air dose rates, ground deposition densities, and concentrations in various environmental samples such as soil, water, and food. This data is being provided not only in numerical format for quantitative analysis but also as distribution maps and time-series graphs for visual understanding. The database system enabled us to spatially and temporally compare large volumes of monitoring data. By using the database functions, characteristics of some representative data in the database was clarified.

An essential part of a protection strategy for radiological emergencies is the development of national dose criteria and of operational intervention levels (OILs) to decide about protective measures for all ten scenarios Germany is preparing. For the process of planning and implementing such protection strategies as required by the German Radiation Protection Law the Federal Ministry BMU has commissioned the German Radiation Protection Commission (SSK) to recommend dose criteria and OILs for emergency response measures. OILs link a chosen dose criterion for a protective action with a suitable measurement of the contamination situation such as ambient dose rate (μSv h⁻¹), contamination level on surfaces (Bq cm⁻²) or activity content (Bq g⁻¹, Bq cm⁻³). This link should adequately model the exposure of persons during a defined exposure period (e.g. seven days, one year) caused by the measured contamination. Dose calculations to quantify OILs should apply assumptions and parameter values that are in tendency realistic and not unduly conservative. OILs have been developed for the following emergency response actions based on radiation measurements:

• Sheltering on the basis of dose rate (μSv h⁻¹) and contamination level(Bq cm⁻²).

• Evacuation on the basis of dose rate (μSv h⁻¹) and contamination level(Bq cm⁻²).

• Establishing a radiological hazard area to implement access andcontamination control on the basis of dose rate (μSv h⁻¹) and contaminationlevel (Bq cm⁻²).

• Contamination control and possibly decontamination of persons and objects(items, goods, vehicles, etc) based on contamination level (Bq cm⁻²).

• A set of precautionary early actions: warning the population not toconsume freshly contaminated food and agricultural measures to reducefood contamination based on dose rate (μSv h⁻¹).

• Application of maximum permitted levels of radioactive contamination offood and feed (Bq kg⁻¹) according to Euratom Regulation.

The new German Radiation Protection Act (StrlSchG) of 31 December 2018 established a reference value of 300 Bq m⁻³ for the annual average radon activity concentration in buildings with recreation and living rooms, as well as in workplaces. It is expected that the reference value will be exceeded in a vast number of buildings throughout Germany and that radon protection measures will become indispensable. A simple and inexpensive radon protection measure for existing buildings is ventilation. In the scope of a joint project, ventilation systems with zone control and heat recovery are to be extended by the control parameter radon activity concentration. A highly sensitive, miniaturized radon monitor will be developed for this purpose, which can be integrated wirelessly into ventilation systems. Radon measurements were carried out in 13 apartments of an unoccupied heated apartment block in Germany over a period of three weeks in the wintertime. High radon activity concentrations were found on all three floors. The maximum values were 14000 Bq m⁻³ on the first floor, 6000 Bq m⁻³ on the second floor, and 2000 Bq m⁻³ on the third floor. Ventilation experiments were carried out in an apartment with high radon activity concentration. Two decentralized ventilation systems with heat recovery were installed in each of the two opposite outside walls. The controlling device of the system was activated wirelessly depending on the radon activity concentration. The radon activity concentration was reduced from 8000 Bq m⁻³ to 800 Bq m⁻³ in a first experiment in the living room.

Several national regulations and good international practices promote the existence of a central register with the results of individual radiological monitoring. In the majority of countries (in the Latin American region), dosimetry data were neither harmonised nor managed by a unique database, and therefore the possibility of using such data for proper characterisation of the radiological conditions, integrally at national level, in a territory or sector, and by practice or occupational category, was very limited. All these considerations justified the need for developing a prototype of a National Dose Register (NDR) for Latin America. The main objectives were the strengthening of safety supervision in nuclear applications and the provision of a surveillance system for occupational exposure as well as the centralisation of personal dosimetry data, compiling all doses evaluated by the different dosimetric service providers. The experience of Cuba and Brazil in the implementation of their national registers was well known, and was accordingly used as the basis for designing this software. The first version of the NDR prototype, developed in the Spanish language, has been designed, developed and validated. So far, 16 countries have started to implement the NDR. The present work describes aspects such as the technical bases of the NDR design, its characteristics and its functionalities. Experience gained during implementation in Latin America is also addressed. Having a common system of dosimetric information management in the region has opened an important space for scientific exchanges between the countries and their competent authorities. The NDR implementation has provided regulatory authorities with a tool that permits the verification of the level of compliance with dose limits and restrictions, as well as allowing them to carry out statistical assessments of the results of individual radiological surveillance that may permit evaluation of the appropriateness and effectiveness of workplace radiation protection programmes, contributing to their optimisation.

There are many aspects of radiological protection in medicine that are different from other areas of activity using ionising radiation. In this paper, the author presents and justify some of these differences and highlight the reasons for and benefits of this consideration for the medical field. It is important to understand the differences as we are all likely to be patients at some point in our lives and be exposed to ionising radiation for imaging procedures several times and, in some cases, for therapeutic indications. The work done by the International Commission on Radiological Protection and other international organisations to produce and recommend a consistent system of radiological protection in medicine for the safe use of ionising radiation in medical practices must be highlighted. We should understand why we do not apply dose limits and dose constraints to patients, as well as why we have three levels of justification when considering the use of ionising radiation for patients. We highlight the relevance of personalised radiation protection in parallel to personalised medical practice, and the importance of an integrated approach for occupational and patient protection, especially for interventional procedures. We also cover the differences between patients and volunteers in biomedical research, the importance of radiation safety in quality assurance programmes (including the consideration of unintended and accidental exposures) for some clinical practices, and the relevance of education and training in radiological protection for medical and health professionals and information on radiation risks for patients. Finally, the ethical issues with regard to the safe use of ionising radiation in medicine and the impact of new technology will be addressed.

Sheltering is one of the countermeasures for protection against radiation exposures in nuclear accidents. The effectiveness of sheltering is often expressed by the reduction factor, that is the ratio of the indoor to the outdoor cumulative radioactivity concentrations or doses. The indoor concentration is mainly controlled by the air exchange rate, penetration factor, and indoor deposition rate. The penetration factor and indoor deposition rate depend on the surface and the materials and structure of windows and doors as it is these openings in the building envelope that control penetration. We investigated experimentally these parameters of I₂ and particles. The experiment was performed in two apartment houses, three single-family houses, and chambers. The obtained penetration factor ranged from 0.3 to 1 for particles of 0.3–1 μm and 0.15–0.7 for I₂ depending on the air exchange rate. The indoor deposition rate for a house room ranged from 0.007 to 0.2 h⁻¹ for particles of 0.3–1 μm and 0.2–1.5 h⁻¹ for I₂.

Large accelerator facilities for scientific research and particle accelerators for radiotherapy have been constructed in Korea. The environments requiring radiological protection procedures have changed substantially and the legal requirements have also increased. However, the same regulatory criteria that are applied to small radiation-generating devices also apply to large accelerator facilities. This study evaluates an approach that uses new criteria based on radiological risk to classify different types of large accelerator facilities. To inform this study, regulations and licensing procedures adopted in various countries were reviewed. The radiological risks from different types of particle accelerators and different types of accelerated particles were investigated in relation to current and planned large accelerators in Korea. The investigation was based on neutron yield and induced radioactivity calculations undertaken using the Monte-Carlo code FLUKA. Based on this analysis, we propose two categories for large accelerator facilities. In the process of the facility construction through to getting an operation permit, we also propose a graded approach, which would require changes in the Korean Nuclear Safety Act. A two-step licensing procedure with a prior review and a final permit for accelerator operation is very practical and conservative in the view of radiation protection. The review process for the revision of the Nuclear Safety Act is currently in progress and a major aspect of this revision reflects the results of this study.

Very recently, Task Group 103 of the International Commission on Radiological Protection (ICRP) completed the development of the paediatric mesh-type reference computational phantoms (MRCPs) comprising ten phantoms (newborn, one year-old, five year-old, ten year-old, and fifteen year-old males and females). The paediatric MRCPs address the limitations of ICRP Publication 143's paediatric reference computational phantoms, which are in voxel format, stemming from the nature of the voxel geometry and the limited voxel resolutions. The paediatric MRCPs were constructed by converting the voxel-type reference phantoms to a high-quality mesh format with substantial enhancements in the detailed anatomy of the small and complex organs and tissues (e.g. bones, lymphatic nodes, and extra-thoracic region). Besides, the paediatric MRCPs were developed in consideration of the intra-organ blood contents and by modelling the micron-thick target and source regions of the skin, lens, urinary bladder, alimentary tract organs, and respiratory tract organs prescribed by the ICRP. For external idealised exposures, the paediatric MRCPs provide very similar effective dose coefficients (DC_Es) to those from the ICRP-143 phantoms but significantly different values for weakly penetrating radiations (e.g. the difference of ∼20 000 times for 10 keV electron beams). This paper introduces the developed paediatric MRCPs with a brief explanation of the construction process. Then, it discusses their computational performance in Geant4, PHITS, and MCNP6 in terms of memory usage and computation speed and their impact on dose calculations by comparing their calculated values of DC_Es for external exposures with those of the voxel-type reference phantoms.

A special session was held in the International Radiation Protection Association (IRPA15) Congress to address the particular challenges facing developing countries regarding radiation protection infrastructure. The objective was to identify and share the key challenges facing developing countries regarding the ability to introduce and establish effective radiation protection programmes. The experiences of key international organisations (International Atomic Energy Agency, Pan American Health Organisation and World Health Organisation) that have support programmes were discussed, along with a perspective from several countries with developing programmes. The key common challenges include: governmental commitment at senior levels, with provision of the necessary resources: establishment of an independent regulatory body and related infrastructure: appropriate numbers of qualified staff in all necessary fields, including their education and training: supporting physical infrastructure, such as dosimetry and measurement equipment including calibration laboratories. In addressing these challenges the importance of support from the key international organisations was emphasised. More emphasis should be given to the application of the graded approach. The establishment of support networks at a national or regional level that allow for the sharing of experiences and resources, and that support the wellbeing of isolated professionals, is also crucial. In this aspect the support from wider professional bodies such as IRPA and established national radiation protection societies can also play a key role.

The International Radiation Protection Association, IRPA, promotes the worldwide enhancement of professional competence, radiation protection (RP) culture and practice by providing benchmarks of good practice, as well as encouraging the application of the highest standards of professional conduct, skills and knowledge for the benefit of individuals and society. Enhancing public understanding of radiation and risk is highlighted by experiences from past emergencies, including the accident at Tokyo Electric Power Company's (TEPCO) Fukushima Daiichi Nuclear Power Plant in 2011 and the following post-disaster recovery, as one of the most important challenges, and this challenge is common across almost all public interfaces regarding radiation and risk. To this end IRPA has been continuing a Task Group activity for Public Understanding since 2013. After a series of workshops in various regions of the world, the IRPA draft guidance was developed and issued for consultation of the Associate Societies in 2019. Through these processes, IRPA received a lot of helpful comments and suggestions. IRPA finally published 'Practical Guidance for Engagement with the Public on Radiation and Risk' on the IRPA website in October 2020. The objective of the guidance is two-fold. Firstly, it is to enthuse all of us in our profession to become more active public advocates for RP. Secondly, it is to provide information, experiences and techniques to help us to become more effective and comfortable in this challenging task. This paper provides a key summary of the published IRPA guidance.

In the past, Brazil has already exploited its immense mineral reserves of rare earth elements. The industrial plants that processed these rare earth ores were contaminated with radionuclides, this happened because at that time there was no legal framework to prevent it. When it was necessary to close these sites, the areas contaminated with radionuclides were remedied during the decommissioning process. This article reports on the steps in the remediation process of an area in one of these facilities and also describes and discusses the methodology applied to ensure that the final planned and authorized radiation levels were effectively achieved during the remediation of this area, located in the largest city in the country. For that, results of the analyses carried out by the operator were the object of comparative analytical tests to verify the quality of the reported data. In order to avoid contaminated and abandoned facilities in the future, it is recommended that the financial planning of industrial facilities with specific environmental and radiological characteristics take into account all the associated costs to be considered environmentally sustainable.

The coordinated organisation of decommissioning, remediation of legacy sites and facilities and management of the resultant waste materials has long been recognized as complex, involving technical challenges, safety and security issues, and a wide range of stakeholder interests. To help address these matters, an international workshop was held in November 2019 in Tromsø, jointly organized by the Norwegian Radiation and Nuclear Safety Authority and the Nuclear Energy Agency, in cooperation with the International Commission on Radiological Protection and the International Atomic Energy Agency. The workshop was the third in series hosted by DSA. The first, in 2015, considered regulatory supervision of legacy sites from recognition to resolution; the second, in 2017, considered the need for an overall process, recognising the links between legacies and the decommissioning of major nuclear installations, the management of contaminated areas and the management of the corresponding radioactive waste. The focus of the Tromsø workshop was on incorporating optimization into that overall process. Attendance included 66 participants from 17 countries, as well as representatives from international organizations. The 29 presentations and associated discussion resulted in a set of recommendations supporting the development of a coherent and practical framework for optimization of decommissioning, legacy site management, and related waste management activities. This paper provides an overview of the presented material and discussion, and provides further information and suggestions for taking forward the recommendations. It is hoped that these ideas, along with the many further inputs from other international organisations and forums, will support the completion of work to implement these recommendations, leading to international guidance on the construction of an overall process for decommissioning and legacy management from a multidisciplinary perspective. That guidance should support holistically optimised management of current projects and help to avoid the future creation of new legacies.

In compliance with the fundamentals of the government's policy on nuclear and radiation safety, Russia is continuing to implement its national program for decommissioning its nuclear legacy. Under this program, the State Atomic Energy Corporation, 'Rosatom', is carrying out decommissioning and remediation of the Navy's former shore technical bases (STBs) in the Russian Far East. Along with the 'old problems' accumulated during the operation of STBs in the past, new challenges arise because of the planned intensification of radioactive waste (RW) management on the site in the nearest future. The paper presents the results of comprehensive environmental monitoring at the site of temporary storage for spent nuclear fuel (SNF) and RW at Sysoeva Bay, located in Primorsky Krai. One of the site's features is the cross contamination of the environment with radioactive substances and nonradiological pollutants. The dominant radionuclides in the environmental media are ¹³⁷Cs, ⁹⁰Sr, and a minor contribution from ⁶⁰Сo. The soil contamination with artificial radionuclides predominantly relates to the category of industrial waste with local areas classified as very low-level RWs. The contamination penetrated the underground water via migration from the damaged SNF and RW storage facilities. Along with cesium and strontium radionuclides, widespread groundwater pollution with heavy metals (I–III hazardous classes), including Be and As, was revealed. Moreover, the exceedance of permissible levels of Cd reaches 1000 times, and that of radionuclides (⁹⁰Sr)reaches 50 times. It dictates the necessity to improve the environmental impact assessment by accounting for the nonradiological pollutants in monitoring design. The radiological conditions in the residential area are characterized by the regional background levels. The average annual effective dose of public exposure due to artificial sources does not exceed 40 µSv.

The hazards associated with radium-containing materials were largely unknown when they were first introduced into household and other products over a century ago. Radium was also originally thought to have beneficial health properties, leading to confusion amongst the public about the safety of radium in household products and food items. When the adverse health effects associated with radium were discovered and became well known, radium products became unpopular and were prohibited in some countries. In the United States, after the hazards associated with radium became known, radium was first regulated by individual states in the late 1920s and early 1930s. Later, the US Nuclear Regulatory Commission (NRC) was given a role in the regulation of discrete sources of radium with the passage of the Energy Policy Act of 2005. After passage of the Act, the NRC began to systematically identify sites around the country where radium was used and reached out to site owners to determine whether existing radium contamination could pose a risk to public health and safety and the environment. The NRC devised a graded approach in response to its new regulatory responsibilities to address potential public health and safety issues at legacy radium sites. By September 2019, the NRC had dispositioned all the sites that were identified as having potential contamination from historical radium within its regulatory purview in non-Agreement States. The staff worked with site owners and federal, state and local officials, as needed, to properly disposition the sites to ensure that each site either meets the applicable criteria for unrestricted use or has controls in place to limit access during remediation so that no site poses an unacceptable risk to public health and safety and the environment.

This article gives an overview of Russian legislation and international recommendations on the safe management regulation of the accumulated very low level radioactive waste (RW), provides the comparison of Russian and international criteria for RW attribution to this or that class and also the existing radiation safety requirements. This article also deals with the difficulties in management of production waste containing radionuclides. Criteria and standards were selected from international (ICRP and IAEA publications) and Russian (Federal Law on Management of Radioactive Waste, Government Decree on Radioactive Waste Classification, The Basic Sanitary Rules of Radiation Safety) documents for comparative analysis. International and Russian criteria for the radioactive materials attribution to RW and production waste containing radionuclides were compared during the analysis. A number of radionuclides for which it is necessary to establish such criteria have been identified. It was found that Russian classification of radioactive materials is generally consistent with IAEA classification. Practices of managing production waste containing radionuclides (protection from contact with the environment, the placement in the long-term storage facilities or disposal) depend on the period of potential hazard of radionuclides. The management of production waste containing radionuclides requires a separate system which should be developed in accordance with the RW management system.

Ukraine has accumulated large amounts of Chernobyl-origin emergency radioactive waste stored in the Chernobyl Exclusion Zone and beyond, as well as legacy radioactive waste in the Radon-type facilities and military sites of the former Soviet Union. Management of such radioactive waste requires the application of a graded approach, in particular, ranking of sites with such radioactive waste by the degree of hazard. Based on the results of ranking, a decision is made on one of the three options: urgent removal of radioactive waste from the site, delayed removal of radioactive waste from the site, and absence of necessity to remove radioactive waste from the site. If it is decided to leave radioactive waste at the site, the graded approach determines the scope of measures to maintain the safety level of that site. This paper presents methodological aspects and experience of the practical application of the graded approach to ensure the safe management of emergency and legacy radioactive waste. In particular, it includes the experience of the Ukrainian State Scientific and Technical Center for Nuclear and Radiation Safety in expert reviews of safety assessments of such sites with emergency and legacy radioactive waste, results of their ranking by degree of hazard, designs for removal of radioactive waste from sites, and establishment of levels for the remediation of territories.

Thirty-five years have passed since the moment of the disaster at the Chernobyl nuclear power plant. It is quite a sufficient period to assess the correctness of the organisation of medical care for victims, to summarise the results of monitoring the health status of various groups of persons involved in the accident, including its direct participants. Radiation from a massive source of relatively uniform gamma radiation and a heterogeneous source of beta radiation can cause affected people to develop acute radiation syndrome (ARS) of varying severity, including non-curable forms of the disease ARS developed in 134 patients; 28 patients from 134 with ARS died in a short time (100 d) after exposure. Among the patients whose disease ended in death, 2/3 of the outcome could be due to radiation skin lesions (19 people). Treatment of ARS varying severity, which was combined with common skin burns with beta radiation, requires long-term specialised treatment. The experience of treating this group of patients has demonstrated that the indications for bone marrow transplantation in the curable form of ARS are limited. The percentage of victims who have absolute indications for allogeneic bone marrow transplantation and in whom this procedure will lead to an improved prognosis for life is very small. Recovery of own myelopoiesis and survival are possible after whole-body irradiation from 6 to 8 Gy, which was found after rejection of haploidentical human leucocyte antigen transplantation, as well as in patients who did not use bone marrow transplantation due to the absence of a corresponding donor. Patients who have undergone ARS need lifelong medical supervision and the provision of necessary medical care.

The main purpose of this study was to compare the parameters of computed tomography (CT) and the corresponding patient doses undergoing chest CT scan examinations in different regions of Brazil, providing the current scenario of how these procedures are being carried out in the country as well as the patient dose distribution. Thirty institutions, across 17 states and the Federal District, participated in the survey. The evaluation included 30 multislice CTs of seven different models, manufactured by General Electric (GE) Healthcare. For each institution, data from 10 adult chest CT examinations, performed without contrast, were collected remotely. The analysis of the results showed a significant difference of the CTDI_vol values, ranging from 1.1 mGy to 46.6 mGy in seven institutions. The mean value of CTDI_vol was higher than values found in the literature and the UK Reference Levels. It was also observed that, regardless of the region of the country, for the same CT model, different scanning parameters were used, which resulted in CTDI_vol up to 5 times higher in some institutions. Repetitions of CT acquisitions and scouts with radiation field dimensions larger than the region of interest were found in 25% of chest examinations, resulting in higher absorbed doses. The results of this work show a mapping of the chest CT procedures, which enables the establishment of strategic plans for the country. In addition, each institution will be able to implement an appropriate optimization program and establish institutional reference levels.

The aim of the present study was to describe patient dose indicator levels during intra-arterial catheter (IAC) implantation for liver chemotherapy, and to determine factors affecting the dose indicators. Between January 2017 and January 2019, 61 patients with hepatic metastases from colorectal cancer were retrospectively included. Interventions were carried out in a standardised manner by three experienced radiologists on the same angiographic table without changes in protocol parameters. For each patient, clinical, radiological and dosimetry data were collected, including the air kerma area product (KAP), part of KAP due to the fluoroscopy and fluoroscopy time (FT), total kerma at the reference interventional point and peak skin dose (PSD). Local dose reference levels (RLs) were determined as the third quartile of the patient dose distributions. Univariate and multivariate analysis of factors affecting dose indicators was performed. The mean KAP was 111 Gy cm², the mean reference point air kerma (Ka,r) was 648 mGy, the mean PSD was 613 mGy, and the mean FT was 3190 s (62% of the KAP). The mean cone beam computed tomography dose was 37.3 ± 11.8 Gy cm², which accounted for 37% of the KAP. The RL could be proposed taking into account the third quartiles (KAP = 164.6 Gy cm², Ka,r = 904.5 mGy, FT = 4011 s and standard deviation = 772.7 mGy). The factors affecting dose indicators were related to the patients (sex, cardiovascular risk factors, weight, body mass index), to the vascular anatomies (coeliac trunk angulation) and to the procedures (number of embolised arteries). This study allowed a better understanding of dose indicators and factors affecting these indicators during the implantation of IACs for hepatic chemotherapy, which is a long and difficult procedure. Local dose RLs were determined. Multicentre, multi-equipment studies are necessary.

Cardiac and liver computed tomography (CT) perfusion has not been routinely implemented in the clinic and requires high radiation doses. The purpose of this study is to examine the radiation exposure and technical settings for cardiac and liver CT perfusion scans at different CT scanners. Two cardiac and three liver CT perfusion protocols were examined with the N1 LUNGMAN phantom at three multi-slice CT scanners: a single-source (I) and second- (II) and third-generation (III) dual-source CT scanners. Radiation doses were reported for the CT dose index (CTDI_vol) and dose–length product (DLP) and a standardised DLP (DLP_10cm) for cardiac and liver perfusion. The effective dose (ED_10cm) for a standardised scan length of 10 cm was estimated using conversion factors based on the International Commission on Radiological Protection (ICRP) 110 phantoms and tissue-weighting factors from ICRP 103. The proposed total lifetime attributable risk of developing cancer was determined as a function of organ, age and sex for adults. Radiation exposure for CTDI_vol, DLP/DLP_{10 cm} and ED_{10 cm} during CT perfusion was distributed as follows: for cardiac perfusion (II) 144 mGy, 1036 mGy·cm/1440 mGy·cm and 39 mSv, and (III) 28 mGy, 295 mGy·cm/279 mGy·cm and 8 mSv; for liver perfusion (I) 225 mGy, 3360 mGy·cm/2249 mGy·cm and 54 mSv, (II) 94 mGy, 1451 mGy·cm/937 mGy·cm and 22 mSv, and (III) 74 mGy, 1096 mGy·cm/739 mGy·cm and 18 mSv. The third-generation dual-source CT scanner applied the lowest doses. Proposed total lifetime attributable risk increased with decreasing age. Even though CT perfusion is a high-dose examination, we observed that new-generation CT scanners could achieve lower doses. There is a strong impact of organ, age and sex on lifetime attributable risk. Further investigations of the feasibility of these perfusion scans are required for clinical implementation.

Many laboratories around the world work on the issue of protection against ionising radiation. It is a very broad topic, covering both the protection of members of the public and workers exposed to ionising radiation, based on personal or environmental monitoring. Thermoluminescence detectors are commonly used for this purpose, which is accepted in most countries. The entire process of dose evaluation with such dosimeters can be divided into several steps. Undoubtedly, one of the most important steps is the calibration procedure. The calibration should be performed in conditions as similar as possible to those experienced during the exposure. Moreover, the calibration is performed using only the Cs-137 source. This article presents results of Panasonic UD-802 irradiation dosimeters in different radiation fields generated by Cs-137, Kr-85, Sr-90/Y-90 and an x-ray tube, series N, and at different angles such as 0°, 30°, 60°, 90°. On the basis of the obtained results, the calibration coefficients and correction factors were determined in relation to calibration based on Cs-137 or Sr-90/Y-90 irradiated at 0°.

The aim of this work was to investigate the effect of patient and cohort size on the overall uncertainty associated with dose audit using radiography of the abdomen as the exemplar. Water equivalent diameter Dw was used as the surrogate for patient size and its distribution (σ(Dw)) was used to quantify the effect of sample size. The more precise the kerma area product calibration, the more patients are required in the cohort to have the same impact on the overall uncertainty. Patient sample sizes of 300–400 will result in expanded uncertainties approaching the theoretical limit of double the measurement uncertainty when audits are performed with instruments having measurement uncertainties equal to ±7%, ±10% or ±12.5%. By way of example, for a field instrument with a measurement uncertainty of ±10%, a minimum sample size of 350 is required to achieve a total expanded uncertainty of ±21%. In the case of instruments with associated measurement uncertainty of ±3.5%, patient sample sizes of 300–400 will result in expanded uncertainties of approximately ±10%. From review of the literature and comparison with the results obtained here, it is conjectured that for radiographic dose audits of all parts of the trunk the contribution to overall uncertainty due to patient and sample size could be predicted using an indicative value for σ(Dw) of 3.4 where local data is not available.

The aim was to determine typical values of diagnostic reference level (DRL) quantities for the computed tomography (CT) part of the most common positron emission tomography—computed tomography (PET-CT) procedures in Slovenia. The most common PET-CT procedures were identified, and data collated for 565 patients imaged in all three PET-CT units in Slovenia during a time span of 11 months. As the number of facilities is too low to establish national DRLs, we followed ICRP recommendations and determined typical values of DRL quantities as the median values of the pooled set of data. Mean, median, and standard deviation of CT dose index (CTDI_vol) and total dose length product (DLP) for the CT part of the most common PET-CT procedures were determined for pooled data as well as for each PET-CT unit. The data were compared between all three units to identify possible outliers that would likely benefit from optimization. Three most common CT protocols covering approximately 2/3 of all PET-CT imaging performed in Slovenia were considered: from the base of the cranium to the middle of the femur, from the top of the head to the middle of the femur, and for the whole-body PET-CT. The established typical values in terms of total DLP were 295, 359, and 676 mGyċcm, respectively; and in terms of CTDI_vol 3.05, 3.22, and 3.60 mGy, respectively. Comparing the data between all three units showed significantly higher (p < 0.001) patient doses on one unit, indicating a need for optimization. The results present the first-time data on the national typical values of DRL quantities for the CT part of most common PET-CT procedures in Slovenia. While the determined typical values are within the DRL values established in some other countries, significant differences were found between the individual units included in the study.

Dose equivalent limits for single organs are recommended by the ICRP (International Commission for the Radiological Protection publication 103). These limits do not lend themselves to be measured. They are assessed by convoluting conversion factors with particle fluences. The Fluence-to-Dose conversion factors are tabulated in the ICRP literature. They allow assessing the organ dose of interest using numerical simulations. In particular, the literature lacks the knowledge of local skin equivalent dose (LSD) coefficients for neutrons. In this article, we compute such values for neutron energies ranging from 1 meV to 15 MeV. We use FLUKA, MCNP and GEANT4 Radiation transport Monte-Carlo simulation codes to perform the calculations. A comparison between these three codes is performed. These calculated values are important for radiation protection studies and radiotherapy applications.

Increased x-ray exposure to physicians' eye lenses during radiology procedures is a significant concern. In this study, x-ray exposure to the eye was measured using an anthropomorphic head phantom, with and without radiation-protective devices, to examine the dose of x-ray radiation that physicians are exposed to during endoscopic retrograde cholangiopancreatography (ERCP). X-ray exposure of the eye was measured using novel dedicated direct eye lens dosimeters that could specifically measure H_p(3) during the ERCP procedure. The spatial dose in the height direction of the physician was measured using an ionization chamber dosimeter. Eye dosimeters were attached inside and outside the lead (Pb) glasses attached to the head of the human phantom to demonstrate its protective effect. Irradiation from the system lasted for 30 min. When the overcouch x-ray tube system is used, the cumulative radiation dose over the 30 min x-ray fluoroscopy time, without the use of radiation-protective devices, to the left and right eyes was 3.7 and 1.5 mSv, respectively. This dose was estimated to be the dose to the lens per therapeutic ERCP examination. With radiation-protective glasses, the dose reduced to 1.8 and 1.0 mSv for the left and right eye, respectively. The results of our study indicated that radiation exposure to the eye was reduced by up to 80.0% using Pb glasses and by 96.8% using radiation-protective curtains. Our study indicates that a physician's maximum radiation exposure to the eyes during an ERCP procedure may be above the level recommended by the International Commission on Radiological Protection when the physician does not use radiation-protective devices. The eyewear, which is larger and fitted more closely to the face, provided a better protection effect even with a low lead equivalence, demonstrating that the shape of eyewear is important for protective function.

Yttrium-90 (Y-90) radioembolization for the treatment of hepatocellular carcinoma can present safety challenges when transplanting recently treated Y-90 patients. To reduce surgeons' contact with radioactive tissue and remain within occupational dose limits, current guidelines recommend delaying transplants at least 14 days, if possible. We wanted to determine the level of radiation exposure to the transplant surgeon when explanting an irradiated liver before the recommended decay period. An ex-vivo radiation exposure analysis was conducted on the explanted liver of a patient who received Y-90 therapy 46 h prior to orthotopic liver transplant. To estimate exposure to the surgeon's hands, radiation dosimeter rings were placed inside three different surgical glove configurations and exposed to the explanted liver. Estimated radiation doses corrected for Y-90 decay were calculated. Radiation safety gloves performed best, with an average radiation exposure rate of 5.36 mSV h⁻¹ in the static hand position, an 83% reduction in exposure over controls with no glove (31.31 mSv h⁻¹). Interestingly, non-radiation safety gloves also demonstrated reduced exposure rates, well below occupational regulation limits. Handling of Y-90 radiated organs within the immediate post-treatment period can be done safely and does not exceed federal occupational dose limits if appropriate gloves and necessary precautions are exercised.

This study presents a comparison of novel pregnant model phantoms with a handmade phantom in terms of shape and radiation measurement points to determine which model is more suitable for measuring the foetal radiation dose during x-ray examinations. Novel pregnant model phantoms were constructed using an anthropomorphic phantom in combination with two differently-sized custom-made abdomen phantoms simulating pregnancy, which were constructed from a polyurethane resin. The size and shape of the polyurethane resin were designed based on abdominal sizes and shapes collected from the computed tomography examinations at 18 pregnant patients of one hospital. The handmade pregnant model phantom was constructed using an anthropomorphic phantom and a beach ball containing water. Compared with the handmade phantom, there were additional dose measurement points on the novel pregnant model phantoms. Our model phantoms improved upon the handmade phantom in terms of shape and radiation measurement points. We produced pregnant model phantoms that simulated the shapes and sizes of actual patients for the first time.

As we progress towards more diverse, equitable, and inclusive communities, workplaces, and organizations in radiation protection (RP), we begin to consider the experiences of our fellow radiation protectionists in parallel with our own. This is to identify, and ideally take down, barriers to pursuing a fulfilling career and positive professional relationships. Recognition and active consideration of differential experiences and needs will help promote both personal and community level success. Over the past few years there have been concerted efforts within the RP community to consider and promote the participation of women. An example outcome of this effort is that we are seeing more women assuming prominent leadership positions in our community. As we celebrate the progress made towards equity, specifically with respect to women, it is important to consider that other factors such as race and gender identity can present their own barriers. Those at the intersection of these or other identities often find themselves in the so-called 'double bind' of more pronounced, or stacking, barriers to success. This paper briefly highlights the need for considering the intersectionality of race and gender in the promotion of equity for all women.

The increasing use of computed tomography (CT) and other relatively high radiation dose exams in a recurrent manner result in radiation risks to individual patients. Recent studies have provided alarming information not only to the radiological community but also to referring physicians. We, as referring physicians, are often implicated in the overuse of imaging. However, a recent paper rightfully summarized the situation that despite the best use of available clinical decision support system for prescribing an imaging exam at a major hospital in the USA, many patients were found to have high cumulative doses. Motivated by the cue provided by the paper in this very journal, we decided to come forward with a possible solution taking the example of the drug prescription system that we routinely use. We provide a template to translate prescription drug monitoring program to ionising radiation imaging. We suggest that all body CT exams should be monitored at an individual, prescriber, and institution level for frequency of use. Furthermore, there should be radiation risk stratification of an individual patient based on the cumulative radiation burden in recent years. Further, an individual's radiation risk-stratified in different risk levels should be available for use by the referring/ordering clinicians at the point of care. Finally, we feel distanced by the use of multiple scary radiation dose quantities in different imaging modalities and would prefer as simple a metric as 'milligram.'