Table of contents

Over the past decades, the International Commission on Radiological Protection (ICRP) has used radiation detriment, which is a multidimensional concept to quantify the overall harm to health from stochastic effects of low-level radiation exposure of different parts of the body. Each tissue-specific detriment is determined from the nominal tissue-specific risk coefficient, weighted by the severity of the disease in terms of lethality, impact on quality of life and years of life lost. Total detriment is the sum of the detriments for separate tissues and organs. Tissue weighting factors for the calculation of effective dose are based on relative contributions of each tissue to the total detriment. Calculating radiation detriment is a complex process that requires information from various sources and judgements on how to achieve calculations. As such, it is important to document its calculation methodology. To improve the traceability of calculations and form a solid basis for future recommendations, the ICRP Task Group 102 on detriment calculation methodology was established in 2016. As part of its mission, the history of radiation detriment was reviewed, and the process of detriment calculation was detailed. This article summarises that work, aiming to clarify the methodology of detriment calculation currently used by ICRP.

Nuclear medicine (NM) procedures for diagnosis and treatment of disease are performed routinely in hospitals throughout the world. These involve preparation and administration to patients of pharmaceuticals labelled with radioactive material. The International Atomic Energy Agency (IAEA) and the World Health Organisation highlighted the need for improvement in prevention of medical radiation incidents and accidents in the Bonn Call-for-Action in 2012. An IAEA Technical Meeting was held on prevention of unintended exposures and accidents in NM in 2018 to address the issue. Exposures can take place at any time when radioactive material is being produced and used, and the risk continues after procedures have been completed. Thus there is potential for staff or members of the general public to be exposed, as well as patients. This paper sets out guidelines for incident prevention based on presentations and discussions at the meeting, and review of reports from the literature. It deals with potential incidents in in-house radionuclide production, radiopharmaceutical preparation, administration to patients, and following a procedure, as well as aspects in management of radioactive materials. Special attention has been paid to therapeutic procedures, as these have the potential to cause more harm to patients from erroneous administrations, including tissue reactions from extravasation of radiopharmaceutical, and could lead to significant contamination events. Administration of NM therapy is generally contraindicated in pregnancy. Identification of any patient who may be pregnant is crucial and it might be necessary to verify this with a pregnancy test for patients within the age band considered to be fertile. Inclusion of NM therapy incidents in the IAEA automated reporting system SAFRON is recommended. In summary, the paper aims to highlight errors that could occur during different phases of NM procedures in order to aid prevention of incidents. The value of periodic audit in evaluating systems in place on a regular basis is emphasised. Approaches to incident investigation and follow-up are described, and the need to ensure corrective action is taken to address any deficiencies stressed.

In their most recent recommendations, the International Commission on Radiological Protection (ICRP) proposed the use of a set of updated tissue and radiation weighting factors for the calculation of the effective dose. This recommendation was adopted in the European Union by the directive 2013/59/EURATOM in 2013 and implemented in the corresponding radiation protection regulations in Germany in 2018. In this study, we investigate the impact of the new weighting factors according to ICRP 103 on the dose rates of the effective dose due to the exposure of aircrew to cosmic radiation with the PANDOCA model for the description of the complex radiation field in the atmosphere. The application of the updated weighting factors leads to a reduction in the rate of the effective dose in the order of 20% to 30% depending on atmospheric and geomagnetic shielding as well as solar modulation.

Americium (Am) biodistribution data obtained after wound contamination in rats were analysed to evaluate and quantify the influence of different physicochemical forms of Am in the presence or absence of plutonium (Pu). The biodistribution data were individual Am daily urinary excretion and tissue retention. The data were analysed with STATBIODIS, a statistical tool developed in the laboratory and based on the R language. Non-parametric methods were selected to comply with the data characteristics. Am systemic tissue retention and urinary excretion data were much greater for contamination with soluble physicochemical forms than insoluble forms. Meanwhile, Am relative biodistribution between the main retention tissues (skeleton, liver and kidney) remained the same. Hence, after absorption into blood the radionuclide behaviour was independent of the physicochemical form. The presence of Pu did not change the Am biodistribution. Comparisons of the biodistribution data from the laboratory with mean values published by other laboratories showed that soluble to moderately soluble forms of Am resulted in similar urine excretion after contamination, whether it was intravenous, intramuscular, subcutaneous injection or incision. Findings from this work will contribute to improve the understanding and interpretation of wound contamination cases with different physicochemical forms and mixtures of actinides including Am.

Medical exposure to ionizing irradiation has become a recognised carcinogenic risk. Balancing the concomitant imaging dose and positioning accuracy is critical in image-guided-radiotherapy (IGRT) especially for children, whose higher biological susceptibility and longer expected life make them more vulnerable to develop secondary cancer. This work aims to evaluate and benchmark the imaging dose and positioning accuracy of a new MV cone-beam-CT (CBCT)-guided IGRT system, Varian Halcyon, against conventional kV CBCT. Weighted-CT-dose-index (CTDI_w) were measured for Varian TrueBeam kV CBCT, and computed for Halcyon MV CBCT using Eclipse system as validated before. Simulating the IGRT workflow, the positioning accuracy of correcting a known shift was tested on various regions of 1-year, 5-year and adult anthropomorphic phantoms, respectively. Inter-scanner and inter-protocol comparisons of dose and accuracy were performed. kV CTDI_w for 'Head', 'Thorax', 'Pelvis' and 'Image Gently' (in CTDI_Φ16cm/CTDI_Φ32cm phantoms, respectively) protocols were measured as 4.5 mGy, 5.4 mGy, 19.3 mGy, and 1.1 mGy/0.5 mGy, respectively. Using 'High Quality' mode, MV CTDI_w in the CTDI_Φ16cm and CTDI _Φ32cm phantoms were computed as 84.5 mGy and 63.8 mGy (imaging length = 28 cm), 68.8 mGy and 55.5 mGy (imaging length = 16 cm), respectively, which were about twice of 'Low Dose' mode. The maximum positioning deviation observed on Halcyon was 0.51 mm ('Low Dose' adult thorax), which was lower than that of standard (0.58 mm, 'Pelvis' adult pelvis) and 'Image Gently' kV CBCT (1.57 mm, adult pelvis). Accuracy of 'Image Gently' kV CBCT head & neck and thoracic imaging were clinically acceptable for adults (maximum deviation = 0.54 mm, adult thorax). Complying with Image Gently campaign, dose-efficient protocols should be used for pediatric IGRT, achieving comparable positioning accuracy on the new Halcyon MV CBCT system relative to the conventional kV CBCT.

In air filter assay for radiological emergency response, radon (²²²Rn) and thoron (²²⁰Rn) progeny are known interferents to transuranic activity estimation. Previous work detailed a conservative, graded approach for TRU alpha activity estimation from air samples void of transuranic activity yet containing varying amounts of radon and thoron progeny. Validation of this method to produce rapid, conservative and defensible transuranic alpha activity estimates was accomplished through introduction of surrogate transuranic activity, ²³⁹Pu and ²³⁰Th check sources, along with the naturally occurring radioactive progeny from an environmental air filter. Following air collection, the filter was centre hole-punched with the transuranic check source placed underneath the filter during counting. With the surrogate transuranic activity introduced into the measurement, verification of the previously studied methodology for rapid transuranic activity estimation was determined with quantifiable conservative bias. 70 environmental filters with various levels of radon progeny and air sampling duration were collected; 35 examined with the ²³⁹Pu check source and 35 studied with the ²³⁰Th check source. To characterise the expected transuranic activity introduced to the counting experiment without the environmental interferents of radon and thoron progeny, 30 blank filters were counted using the described experimental setup with each of the respective surrogate sources. Following characterisation of the sources with blank filters, transuranic activity estimation comparison against the 70 environmental filters with natural background radioactive progeny interferents was accomplished. This work contributes to the comprehensive analysis of operational air samples by detailing validation results for a rapid and conservative transuranic alpha activity estimation methodology.

Reflecting a change in funding strategies for European research projects, and a commitment to the idea of responsible research and innovation in radiological protection (RP), a collective of research institutes and universities have developed a prospective Strategic Research Agenda (SRA) for Social Sciences and Humanities (SSH) in radiological protection. This is the first time such a research agenda has been proposed. This paper identifies six research lines of interest and concern: (1) Effects of social, psychological and economic aspects on RP behaviour; (2) Holistic approaches to the governance of radiological risks; (3) Responsible research and innovation in RP; (4) Stakeholder engagement and participatory processes in RP research, development, policy and practice; (5) Risk communication; and (6) RP cultures. These topics were developed through broad stakeholder consultation, in conjunction with activities carried out in the framework of various projects and initiatives (EU H2020 CONCERT programme, the EU FP7 projects OPERRA, PREPARE and EAGLE, the 2015–2018 RICOMET series of conferences, and the 2014 and 2016 International Symposia on Ethics of Environmental Health); as well as through dialogues with members of the European radiation protection research communities. The six research lines open opportunities to integrate a range of key social and ethical considerations into RP, thereby expanding research opportunities and programmes and fostering collaborative approaches to research and innovation.

We investigated comparisons between patient dose and noise in pelvic, abdominal, thoracic and head CT images using an automatic method. 113 patient images (37 pelvis, 34 abdominal, 25 thoracic, and 17 head examinations) were retrospectively and automatically examined in this study. Water-equivalent diameter (Dw), size-specific dose estimates (SSDE) and noise were automatically calculated from the center slice for every patient image. The Dw was calculated based on auto-contouring of the patients' edges, and the SSDE was calculated as the product of the volume CT dose index (CTDIvol) extracted from the Digital Imaging and Communications in Medicine (DICOM) header and the size conversion factor based on the Dw obtained from AAPM 204. The noise was automatically measured as a minimum standard deviation in the map of standard deviations. A square region of interest of about 1 cm² was used in the automated noise measurement. The SSDE values for the pelvis, abdomen, thorax, and head were 21.8 ± 7.3 mGy, 22.0 ± 4.5 mGy, 21.5 ± 4.7 mGy, and 65.1 ± 1.7 mGy, respectively. The SSDEs for the pelvis, abdomen, and thorax increased linearly with increasing Dw, and for the head with constant tube current, the SSDE decreased with increasing Dw. The noise in the pelvis, abdomen, thorax, and head were 5.9 ± 1.5 HU, 5.2 ± 1.4 HU, 4.9 ± 0.8 HU and 3.9 ± 0.2 HU, respectively. The noise levels for the pelvis, abdomen, and thorax of the patients were relatively constant with Dw because of tube current modulation. The noise in the head image was also relatively constant because Dw variations in the head are very small. The automated approach provides a convenient and objective tool for dose optimizations.

A simplified procedure, using circular disk models with homogeneous electric conductivity as representations for different body parts, has been proposed recently by product standard IEC 62822-3 for the assessment of magnetic field exposure in proximity to current-carrying conductors of welding equipment. Based on such simplified models, worst case coupling coefficients CCE_i(I), i.e. maximum induced electric field strength, normalised for current and frequency, for body parts at different distances d to straight single and double wire arrangements, as well as rectangular loop-shaped current paths are tabulated in the standard. In this work we compared CCE_i(I) values obtained by numerical computations with detailed anatomical models of the hand/forearm with the corresponding values given in IEC 62822-3 for current-carrying single wire conductors along the forearm at distances d = 30, 50 and 100 mm, respectively. Our results clearly indicated that the CCE_i(I) given in the standard may substantially underestimate the actual exposure. Using average values for tissue conductivities the observed extent of underestimation was up to 8.9 dB (factor 2.79) and may be even higher for worst case combinations of tissue conductivities. The reasons for this substantial underestimation are the oversimplified geometry, i.e. the circular disk does not reflect anatomical constrictions of the induction area present in realistic hand/forearm geometries, as well as the missing conductivity contrast between different tissues in the homogeneous disk models. Results of exposure assessment and corresponding minimum distances to components of welding equipment obtained by the simplified disk model approach suggested by IEC 62822-3 should therefore be considered with caution.

Interventional radiology and cardiology are widespread employed techniques for diagnosis and treatment of several pathologies because they avoid the majority of the side-effects associated with surgical treatments, but are known to increase the radiation exposure to patient and operators. In recent years many studies treated the exposure of the operators performing cardiological procedures. The aim of this work is to study the exposure condition of the medical staff in some selected interventional radiology procedures. The Monte Carlo simulations have been employed with anthropomorphic mathematical phantoms reproducing the irradiation scenario of the medical staff with two operators and the patient. A personal dosemeter, put on apron, was modelled for comparison with measurements performed in hospitals, done with electronic dosemeters, in a reduced number of interventional radiology practices. Within the limits associated to the use of numerical anthropomorphic models to mimic a complex interventional procedure, the personal dose equivalent, H_p(10), was evaluated and normalised to the simulated Kerma-Area Product, KAP, value, indeed the effective dose has been calculated. The H_p(10)/KAP_value of the first operator is about 10 μSv/Gy.cm², when ceiling shielding is not used. This value is calculated on the trunk and it varies of +/−30% moving the dosemeter to the waist or to the neck. The effective dose, normalised to the KAP value, varies between 0.03 and 0.4 μSv/Gy.cm². Considering all the unavoidable approximation of this kind of investigations, the comparisons with hospital measurement and literature data showed a good agreement allowing to use of the present results for dosimetric characterisation of interventional radiology procedures.

The dosimetric dependence of ocular structures on eye size and shape was investigated within the standard ICRP Publication 116 irradiation geometries. A realistic transport geometry was constructed by inserting a scalable and deformable stylised eye model developed in our previous study within the head of the ICRP Publication 110 adult male reference computational phantom. Beam irradiations of external electrons, photons, and neutrons on this phantom were simulated using the Monte Carlo radiation transport code PHITS in the geometries of AP, RLAT, PA and ROT. Absorbed doses in ocular structures such as ciliary body, retina, and optic nerves were computed as well as that in lens. A clear dosimetric dependence of ocular structures on eye size and shape was observed for external electrons while only a small dependence was seen for external photons and neutrons. Difference of the tendency was attributed to their depth-dose distributions where spread dose distributions were created by photons and neutrons while more concentrated distributions were created by external electrons.

This study firstly explored the risks of secondary cancer in healthy organs of Chinese paediatric patients with brain tumours after boron neutron capture therapy (BNCT). Three neutron beam irradiation geometries (i.e. right lateral, top to bottom, posterior to anterior) were adopted in treating patients with brain tumours under the clinical environment of BNCT. The concerned organs in this study were those with high cancer morbidity in China (e.g. lung, liver and stomach). The equivalent doses for these organs were calculated using Monte Carlo and anthropomorphic paediatric phantoms with Chinese physiological features. The risk of secondary cancer, characterised by the lifetime attributable risk (LAR) factor given in the BEIR VII report, was compared among the three irradiation geometries. The results showed that the LAR was lower with the PA irradiation geometry than with the two other irradiation geometries when the 2 cm diameter tumour was at a depth of 6 cm on the right side of the brain. Under the PA irradiation geometry, the LAR in the organs increased with increasing tumour volume and depth because of the long irradiation time. As the patients aged from 10–15 years old, the LAR decreased, which was related to the increased patient height and shortened life expectancy. Female patients had a relatively higher risk of secondary cancer than male patients in this study, which could be due to the thinner body thickness and the weaker protective effect on the internal organs of the female patients. In conclusion, the risks of secondary cancer in organs were related to irradiation geometries, gender, and age, indicating that the risk of secondary cancer is a personalised parameter that needs to be evaluated before administering BNCT, especially in patients with large or deep tumours.

Following the Fukushima incident, radiation doses from external exposure accounted for the majority of the total doses. Although countermeasures are being implemented, with the aim of reducing radiation exposure, little information is available on the effects of decontamination on individual doses among the residents of radioactively contaminated areas. To evaluate the effectiveness of the decontamination measures in reducing individual doses, and to examine the influence of the timing of decontamination and the district, data were analysed for 18 392 adults and 3 650 children in Minamisoma City, Fukushima, who participated in a voluntary screening programme using individual radiation dosimeters (Glass Badge) between June 2013 and September 2016. The dose reduction rates (DRR) were calculated for one year by comparing the first and last three-month measurement results between areas with and without decontamination. Using a regression approach and Monte Carlo simulation, the dose reduction rate by decontamination eliminating the effect of physical decay (DRRd') was also estimated as a function of the timing of the decontamination and the dose at the time of starting the decontamination. The annual DRR in areas with decontamination for both adults and children were significantly higher than those in areas without decontamination, depending on the timing of decontamination: 31%–36% for 2013–14 for adults in decontamination areas and 33%–35% for children in decontamination areas, compared to 12%–23% and 13%–23% for adults and children in areas without decontamination, respectively. There was a positive correlation between DRRd' and individual doses, and DRRd' was estimated at 30%–40% for adults and children with doses of 3 mSv y⁻¹ in 2013 and 2014. This study demonstrated that decontamination does lower individual doses from external exposure. The higher the dose at the time of starting the decontamination, the greater the dose reduction rate by decontamination, regardless of the timing of the decontamination. Our study confirms that decontamination was useful for high-dose areas in the later phases of the incident.

General x-ray images have a lower probability of nodule detection than other modalities. Especially in children, the probability of nodule detection can likely drop due to poor image quality from using low radiation dose. To demonstrate the effectiveness of fast non-local means (FNLM) filter to increase the probability of nodule detection in pediatric chest x-ray images and reduce radiation dose while maintaining image quality. Quantitative assessment of normalised noise power spectrum (NNPS), coefficient of variation (COV) and contrast to noise ratio (CNR) were performed after applying four filters (median, Wiener, total variation and FNLM) on a 1-year-old child phantom. A 3D-printed patient nodule phantom was inserted into the phantom. Assessment was performed on AP and LAT view images acquired with the tube voltage reduced to 38 and 27%, and tube current reduced to 84 and 61%, respectively. The results showed the lowest NNPS and COV values and the highest CNR value when the FNLM filter applied. Moreover, the AP view results showed 37% decrease in COV and 30% increase in CNR in images with the FNLM filter applied (images exposed with the tube voltage and current reduced to 29% and 50%, respectively). The LAT view results showed 5% decrease in COV and 36% increase in CNR in images with the FNLM filter applied (images exposed with the tube current reduced by 27%). By applying the FNLM filter, the probability of nodule detection could be increased by denoising and contrast enhancement. Moreover, using the FNLM filter could reduce cancer risk in pediatric patients by reducing radiation dose about 30% to 44%.

A registry for chronic radiation syndrome (CRS), a deterministic effect of chronic exposure to external and/or internal radiation at doses and dose rates exceeding thresholds for tissue reactions, was established within a medical and dosimetry database known as 'Clinics', of the Southern Urals Biophysics Institute at the Federal Medical and Biological Agency of Russia. It includes 2068 CRS cases: 1517 (73.4%) in males and 551 (26.6%) in females. The majority of workers (97.9%) diagnosed with CRS at one of the main facilities of the first Russian nuclear enterprise, Mayak Production Association, were hired in the period 1948–1954. On the date of CRS diagnosis, the mean cumulative red bone marrow (RBM) absorbed doses from external gamma rays were 1.1 ± 0.66 Gy in males and 1.0 ± 0.58 Gy (±standard deviation) in females, with mean annual doses of 0.46 ± 0.33 Gy and 0.38 ± 0.22 Gy, respectively, and maximum annual doses of 0.67 ± 0.46 Gy and 0.55 ± 0.34 Gy, respectively. The frequency of CRS cases significantly increased with the increasing cumulative and mean annual RBM absorbed doses from external gamma rays. The paper presents the structure and descriptive characteristics of the CRS registry as well as prospects for its use.

In this document we present the calculation and experimental validation of a source term for ¹⁸F-production with a cyclotron for medical applications operating at 18 MeV proton energy and 30 μA proton current. The Monte Carlo codes MCNP6 and FLUKA were used for the calculation of the source term. In addition, the radiation field around the ¹⁸O-enriched water target was simulated with the two codes. To validate the radiation field obtained in the simulation, an experimental program has been started using activation samples which are placed close to the water target during an ¹⁸F-production run of the cyclotron. After the irradiation, the samples are analysed and the resulting activation is compared to Monte Carlo calculations of the expected sample activation. We find good agreement between simulations and experimental results, with most calculation to experiment (C/E) ratios well between 0.6 and 1.4.

In July 2017, the International Commission on Radiation Units and Measurements (ICRU) and the International Commission on Radiological Protection (ICRP) proposed the introduction of new operational quantities for external radiation exposure, with the aim of improving coherence between protection quantities and operational quantities within the system of radiological protection. A change in operational quantities will impact both instrumentation and reference radiation fields used for their calibration. This paper evaluates the potential impact of the new quantity ambient dose, H*, meant to replace ambient dose equivalent, H*(10), on two neutron reference fields, the Am-Be source and the CERF high-energy workplace field, and on the response of two models of extended-range neutron rem counters (LINUS and LUPIN). The conclusions are that calibration procedures should in general not be affected and that changes should only be expected in calibration coefficients. Considering the acceptable measurement uncertainties for operational radiation protection, for the extended-range rem counters changes in their design would not be required for measurements outside particle accelerators shielding and for aircrew dosimetry. One can expect that this type of instrument can still be calibrated with Am-Be source neutrons and employed in neutron fields with energy distributions spanning several decades. For uses in radiation fields with very peculiar neutron energy distribution, a specific workplace field calibration may instead be required.

The aim of this study was to demonstrate the usefulness of large sample size patient dose audits for optimisation of CT automatic exposure control (AEC) settings, even when the investigation is limited to only three scanners at a single institution. Pre-optimisation patient dose audits of common CT examinations (n > 200 for each protocol) on three CT scanners (two Philips Brilliance and one Toshiba Aquilion) using radiology information system (RIS) data were conducted showing sub-optimal CT AEC performance on the Toshiba scanner. Based on these results, an optimisation exercise was carried out on the non-optimally performing scanner by phantom measurement and investigation of system configuration. Post-optimisation patient dose audits were subsequently carried out to assess the success of the optimisation exercise demonstrating standardisation of doses; median dose-length-product values were reduced by up to 43% on the sub-optimal scanner without any adverse effect on clinical image quality. This study has demonstrated that large sample patient dose audits using RIS data can be instrumental in identifying and rectifying sub-optimal CT AEC performance, even when the investigation is limited to only three scanners at a single institution.

This work provides dose coefficients necessary to reconstruct doses used in epidemiological studies of tuberculosis patients treated from the 1930s through the 1960s, who were exposed to diagnostic imaging while undergoing treatment. We made use of averaged imaging parameters from measurement data, physician interviews, and available literature of the Canadian Fluoroscopy Cohort Study and, on occasion, from a similar study of tuberculosis patients from Massachusetts, United States, treated between 1925 and 1954. We used computational phantoms of the human anatomy and Monte Carlo radiation transport methods to compute dose coefficients that relate dose in air, at a point 20 cm away from the source, to absorbed dose in 58 organs. We selected five male and five female phantoms, based on the mean height and weight of Canadian tuberculosis patients in that era, for the 1-, 5-, 10-, 15-year old and adult ages. Using high-performance computers at the National Institutes of Health, we simulated 2,400 unique fluoroscopic and radiographic exposures by varying x-ray beam quality, field size, field shuttering, imaged anatomy, phantom orientation, and computational phantom. Compared with previous dose coefficients reported for this population, our dosimetry system uses improved anatomical phantoms constructed from computed tomography imaging datasets. The new set of dose coefficients includes tissues that were not previously assessed, in particular, for tissues outside the x-ray field or for pediatric patients. In addition, we provide dose coefficients for radiography and for fluoroscopic procedures not previously assessed in the dosimetry of this cohort (i.e. pneumoperitoneum and chest aspirations). These new dose coefficients would allow a comprehensive assessment of exposures in the cohort. In addition to providing newly derived dose coefficients, we believe the automation and methods developed to complete these dosimetry calculations are generalizable and can be applied to other epidemiological studies interested in an exposure assessment from medical x-ray imaging. These epidemiological studies provide important data for assessing health risks of radiation exposure to help inform the current system of radiological protection and efforts to optimize the use of radiation in medical studies.

NCRP Report No. 180, 'Management of Exposure to Ionizing Radiation: Radiation Protection Guidance for the United States (2018)' was developed by Council Committee 1. The report builds and expands upon previous recommendations of NCRP and ICRP, covering exposure to radiation and radioactive materials for five exposure categories: occupational, public, medical, emergency workers, and nonhuman biota. Actions to add, increase, reduce or remove a source of exposure to humans require justification. Optimisation of protection universally applies, taking into account societal, economic, and environmental factors; addressing all hazards, and striving for continuous improvement when it is reasonable to do so. Numeric protection criteria for management of dose to an individual for a given exposure situation are provided, and differ in some respects from ICRP. A specific numeric criterion is suitable to be designated as a regulatory dose limit only when the source of exposure is stable, characterised, and the responsible organisation has established an appropriate radiation control program in advance of source introduction. Medical exposure includes patients, comforters and caregivers of a patient, and voluntary participants in biomedical research. Emergency workers are a new exposure category; their exposure is treated separately from occupational, public or medical exposure, and numeric criteria are provided for deterministic and stochastic effects. For nonhuman biota, the focus is on population maintenance of the affected species, and a guideline is provided for when additional assessment may be necessary. In addition, the recommendations emphasise that: ethical principles support decision-making; stakeholder engagement is necessary in deciding suitable management of their radiation exposure; and a strong safety culture is intrinsic to effective radiation protection programs.

In this study, the level of radiation protection and awareness among radiation workers and members of the public in Afghanistan is assessed using two different survey mechanisms. The onsite survey conducted by the regulatory authorities covered 472 facilities while the online survey covering 1200 responses was conducted via the Survey Monkey online survey platform. Both the onsite and the online surveys show that more than 70% of radiation workers have insufficient knowledge of radiation safety and protection rules and regulations while more than 70% of the public just heard about radiation from one source or another. More than 50% of those members of the public, who have been through some sort of medical imaging using radiation were not given any instruction about the radiation hazards. The study is concluded with recommendations to the authorities for raising the knowledge of the radiation workers and general public awareness through launching regular radiation safety and protection training, TV spots and other means of mass media.

Novel germanium (Ge)-doped silica glass fibres tailor-made in Malaysia are fast gaining recognition as potential media for thermoluminescence (TL) dosimetry, with active research ongoing into exploitation of their various beneficial characteristics. Investigation is made herein of the capability of these media for use in diagnostic imaging dosimetry, specifically at the radiation dose levels typically obtained in conduct of Computed Tomography (CT). As a first step within such efforts, there is need to investigate the performance of the fibres using tightly defined spectra, use being made of a Philips constant potential industrial x-ray facility, Model MG165, located at the Malaysian Nuclear Agency Secondary Standards Dosimetry Lab (SSDL). Standard radiation beam qualities (termed RQT) have been established for CT, in accord with IEC 61267: 2003 and IAEA Technical Reports Series No. 457: 2007. A calibrated ionisation chamber has also been utilised, forming a component part of the SSDL equipment. The fabricated fibres used in this study are 2.3 mol% flat fibre (FF) of dimensions 643 × 356 μm² and 2.3 mol% cylindrical fibre (CF) of 481 μm diameter, while the commercial fibre used is 4 mol% with core diameter of 50 μm. The dopant concentrations are nominal preform values. The fibres have been irradiated to doses of 20, 30 and 40 milligray (mGy) for each of the beam qualities RQT 8, RQT 9 and RQT 10. For x-rays generated at constant potential values from 100 to 150 kV, a discernible energy-dependent response is seen, comparisons being made with that of lithium fluoride (LiF) thermoluminescence dosimeters (TLD-100). TL yield versus dose has also been investigated for x-ray doses from 2 to 40 mGy, all exhibiting linearity. Compared to TLD-100, greater sensitivity is observed for the fibres.

Monitoring and protecting of occupational eye doses in interventional radiology (IR) are very important matters. DOSIRIS™ is the useful solution to estimate the 3 mm dose-equivalent (Hp(3)), and it can be worn behind lead glasses. And DOSIRIS™, adjustable according to 3 axes, it is ideally placed as close to the eye and in contact with the skin. So, DOSIRIS™ will be suitable eye lens dosimeter. However, the fundamental characteristics of the DOSIRIS™ in the diagnostic x-ray energy domain (including that of IR x-ray systems) remain unclear. Here, we evaluated the performance of the dosimeter in that energy range. As a result, the DOSIRIS™ has good fundamental characteristics (batch uniformity, dose linearity, energy dependence, and angular dependence) in the diagnostic x-ray energy domain. We conclude that the DOSIRIS™ has satisfactory basic performance for occupational eye dosimetry in diagnostic x-ray energy settings (including IR x-ray systems).

Highlights of the articles in this issue are given in the PDF file.