ICRP Publication 138: Ethical Foundations of the System of Radiological Protection

Recurrent medical imaging exposures for the care of patients: one way forward

Medical imaging is both valuable and essential in the care of patients. Much of this imaging depends on ionizing radiation with attendant responsibilities for judicious use when performing an examination. This responsibility applies in settings of both individual as well as multiple (recurrent) imaging with associated repeated radiation exposures. In addressing the roles and responsibilities of the medical communities in the paradigm of recurrent imaging, both the International Atomic Energy Agency (IAEA) and the American Association of Physicists in Medicine (AAPM) have issued position statements, each affirmed by other organizations. The apparent difference in focus and approach has resulted in a lack of clarity and continued debate. Aiming towards a coherent approach in dealing with radiation exposure in recurrent imaging, the IAEA convened a panel of experts, the purpose of which was to identify common ground and reconcile divergent perspectives. The effort has led to clarifying recommendations for radiation exposure aspects of recurrent imaging, including the relevance of patient agency and the provider-patient covenant in clinical decision-making. CLINICAL RELEVANCE STATEMENT: An increasing awareness, generating some lack of clarity and divergence in perspectives, with patients receiving relatively high radiation doses (e.g., ≥ 100 mSv) from recurrent imaging warrants a multi-stakeholder accord for the benefit of patients, providers, and the imaging community. KEY POINTS: • Recurrent medical imaging can result in an accumulation of exposures which exceeds 100 milli Sieverts. • Professional organizations have different perspectives on roles and responsibilities for recurrent imaging. • An expert panel reconciles differing perspectives for addressing radiation exposure from recurrent medical imaging.

Temporal changes in cumulative mortality risks of cancer, by occupation, in the working population of Japan from 1995 to 2020: a benchmark for radiation risk comparison

The purpose of this study was to provide benchmark data for discussing the tolerability of cancer risk associated with occupational radiation exposure. It focused on differences in cancer mortality risk by occupation among Japan's working population and examined baseline cancer mortality risks and its variations from 1995 through 2020. Data were collected every five years from national vital statistics sources. By focusing on the same types of cancer among radiation induced effects, cumulative mortality risks were calculated for colorectal, lung, and breast cancer (females only) for those aged 15-74. The average cumulative mortality risk for the working population in Japan has decreased by 30%-60% over the past 25 years. Service workers and male managers were at an average risk, among all workers, while clerical workers and transportation and manufacturing workers had about half the average risk. The risks were higher for professionals and female managers, about 1.5-2 times the average for professionals and up to 5 times the average for female managers. The decrease in the average cancer mortality risk in the working population as a baseline suggests that risk tolerance in society might have changed over time. Since differences in mortality by occupation were confirmed, the usefulness of occupational data as a benchmark needs further investigation, as high-risk/low-risk occupations vary by country and region. The results of this study contribute to put radiation risks into perspective with the background risk of cancer.

The ICRP, MELODI, and ALLIANCE workshop on effects of ionizing radiation exposure in offspring and next generations: a summary of discussions

PURPOSE

Task Group 121 - Effects of ionizing radiation exposure in offspring and next generations - is a task group under the Committee 1 of the International Commission on Radiological Protection (ICRP), approved by the Main Commission on 18th November 2021. The main goals of Task Group 121 are to (1) review and update the scientific literature of relevance to radiation-related effects in the offspring of parent(s) exposed to ionizing radiation in both human and non-human biota; (2) to assess preconceptional and intrauterine effects of radiation exposure and related morbidity and mortality; and, (3) to provide advice about the level of evidence and how to consider these preconceptional and postconceptional effects in the system of radiological protection for humans and non-human biota.

METHODS

The Task Group is reviewing relevant literature since Publication 90 'Biological effects after prenatal irradiation (embryo and fetus)' (2003) and will include radiation-related effects on future generations in humans, animals, and plants. This review will be conducted to account for the health effects on offspring and subsequent generations in the current system of radiological protection. Radiation detriment calculation will also be reviewed. Finally, preliminary recommendations will be made to update the integration of health effects in offspring and next generations in the system of radiological protection.

RESULTS

A Workshop, jointly organized by ICRP Task Group 121 and European Radiation Protection Research Platforms MELODI and ALLIANCE was held in Budapest, Hungary, from 31st May to 2nd June 2022. Participants discussed four important topics: (1) hereditary and epigenetic effects due to exposure of the germ cell line (preconceptional exposure), (2) effects arising from exposure of the embryo and fetus (intrauterine exposure), (3) transgenerational effects on biota, and (4) its potential impact on the system of radiological protection.

CONCLUSIONS

Based on the discussions and presentations during the breakout sessions, newer publications, and gaps on the current scientific literature were identified. For instance, there are some ongoing systematic reviews and radiation epidemiology reviews of intrauterine effects. There are newer methods of Monte Carlo simulation for fetal dosimetry, and advances in radiation genetics, epigenetics, and radiobiology studies. While the current impact of hereditary effects on the global detriment was reported as small, the questions surrounding the effects of radiation exposure on offspring and the next generation are crucial, recurring, and with a major focus on exposed populations. This article summarizes the workshop discussions, presentations, and conclusions of each topic and introduces the special issue of the International Journal of Radiation Biology resulting from the discussions of the meeting.

Increasing the public awareness of justification

One of the requirements of the UK Ionising Radiation (Medical Exposure) Regulations 2017 is that all medical exposures must be justified before the exposure can proceed. One of the main elements of justification is a determination that the medical benefits from the exposure will exceed the associated radiation detriment. The field of medical exposure to ionising radiation is in the rare position of having this explicit legal requirement for net benefit. In this article it is argued that, although separate information on benefit and detriment is also required for implied or explicit informed consent prior to exposure, justification comes first, is simple to explain, and is easily related to the commonly understood basis of medical ethics. It seems reasonable, therefore, to make patients and the public more aware of the protection that UK law already provides for them. A proposal for a single-sentence general statement on justification is made.

Comparing benefit and detriment from medical diagnostic radiation exposure using disability-adjusted life years: towards quantitative justification

Justification of medical radiation exposure is one of the main elements of radiation protection for patients. For a medical exposure to proceed, the benefit from the procedure must have been determined to be greater than the detriment. It is rare, however, that justification can be stated quantitatively as a ratio of benefit to detriment, or as a net benefit, and this is particularly true for medical diagnostic exposures associated with non-fatal diseases where survival statistics do not apply. The concept of the disability-adjusted life year (DALY) is well established as a measure of disease severity in public health, and there have been calls to revise the international system of radiation protection dosimetry to employ the DALY as a measure of radiation detriment. This paper looks at possible routes to quantify the benefit and detriment aspects of justification based on initial published results for the use of the DALY as a measure of radiation detriment, together with established values of DALY for a range of diseases. Although spreadsheet-style solutions for the calculation of a justification factor based on statistical life tables can be devised, these will be shown to have some limitations. A justification factor based on the rate of change of benefit divided by the rate of change of detriment following medical exposure is proposed. This factor is simple to calculate, is age independent, can apply to non-fatal diseases and is argued to have logical and ethical advantages for the explanation of the relative benefits and detriments of radiological procedures to patients.

Ethical and societal aspects of radiological protection for offspring and next generations

PURPOSE

Over the last decade or so, ethical and societal aspects of radiological protection have received increasing attention. This is also reflected in the publications of the International Commission on Radiological Protection (ICRP). The current paper aims at identifying relevant ethical and societal topics which should receive attention in the context of radiological protection for offspring and next generations.

MATERIALS AND METHODS

We present a non-comprehensive review of the subject, based on presentation made at an ICRP workshop in Budapest in 2022. We first discuss the ethical values promoted by ICRP, and the application of these values in cases of (potential) pre-conceptual and prenatal radiation exposures. We then consider experience gained after the Fukushima accident indicating particular societal concerns about the health effects of such exposures.

RESULTS AND CONCLUSIONS

Beneficence/non-maleficence, prudence, justice and dignity, the "core values" of the system of radiological protection have special roles to play when heritable and/or in utero effects are to be considered. Prudence, in particular, must be taken account of in view of the fact that solid scientific data in humans are largely lacking in this area, and it is necessary to rely on insights from animal experiments as well as theoretical considerations. As regards societal considerations, the perception of risk among (potentially) affected populations needs to be taken seriously. Accountability, transparency, and inclusivity, the "procedural values" promoted by ICRP for the practical implementation of the system of radiological protection play a central role in overcoming skepticism and creating trust. Stakeholder involvement should emphasize cooperation and dialogue, which allows for the joint evaluation of an exposure situation by experts and affected people.

Radiological protection in human research ethics using a case study: toward update of the ICRP Publication 62

The benefits of biomedical research involving humans are well recognised, along with the need for conformity to international standards of science and ethics. When human research involves radiation imaging procedures or radiotherapy, an extra level of expert review should be provided from the point of view of radiological protection. The relevant publication of the International Commission for Radiological Protection (ICRP) is now three decades old and is currently undergoing an update. This paper aims to provoke discussions on how the risks of radiation dose and the benefits of research should be assessed, using a case study of diagnostic radiology involving volunteers for whom there is no direct benefit. Further, the paper provides the current understanding of key concepts being considered for review and revision-such as the dose constraint and the novel research methods on the horizon, including radiation biology and epidemiology. The analysis revisits the perspectives described in the ICRP Publication 62, and considers the recent progress in both radiological protection ethics and medical research ethics.

Impacts of environmental decontamination on the rebuilding of returnees' lives after the Fukushima accident

Environmental decontamination after a nuclear disaster not only contributes to reducing the public's exposure to radiation, it also introduces waste disposal issues arising from the decontamination process. In addition to that issue, the optimisation of decontamination efforts necessitates the consideration of various environmental, economic, and societal factors. Stakeholders' perspectives are important for identifying the multifaceted aspects to be considered. We conducted a semi-structured interview survey in 2019 with ten residents in a rural community in Fukushima, Japan, which experienced a six-year-long evacuation due to the 2011 Fukushima Daiichi Nuclear Power Plant accident. The main survey questions addressed returnees' perceptions of the decontamination of farmlands and forests. The 'Steps for Coding and Theorization' procedure was used for qualitative analysis. The analysis illuminated the positive and negative impacts of the decontamination process on the rebuilding of the returnees' rural lives from various perspectives and identified elements to be considered for the optimisation of future remediation efforts. The removal of radioactive materials had a positive psychological impact on the returnees, fostering a sense of security that their crops were safe and instilling confidence that the high-quality environment of the region had been restored. These aspects were not included among the initial governmental objectives for decontamination, which were aimed solely at reducing radiation exposure. By contrast, the removal of fertile topsoil from farmland had a negative impact on the residents, making them hesitant to resume farming. Our findings suggest that emphasising procedural fairness in decision-making of decontamination options such as reflection of stakeholders' opinions led to residents perceiving their post-decontamination situation more positively. Our results provide valuable insights for optimising remediation strategies for the recovery process following a significant nuclear accident.

When citizen science meets radon building diagnosis: Synthesis of a French pilot project developed in the framework of the European RadoNorm research project

As part of the European RadoNorm research project, citizen science pilot projects focusing on the management of radon risk in houses have been implemented in four countries. This article describes the methodological basis, the development and the results of the French pilot project. Building on an initial review of existing literature, the pilot project aims to frame a 'participatory approach' aligned with the standards and recognized practices of citizen science. Particular attention was given to the management of data and the inclusion of ethical considerations. The focal point of the project was the process of radon building diagnosis which is supposed to be carried out whenever (high) radon concentrations are measured and should be prerequisite to mitigation works. As experience shows, however, this diagnosis is hardly implemented in France. To help remedy this situation, the pilot project recruited citizens already aware about radon from Pays Vesoul Val-de-Saône (East of France) to test an existing online self-evaluation guide for radon diagnosis, report on their operational experience and meet with radon/building experts. This enabled citizens to contribute to improvements in form and content to the guide and to ensure that it would be better fit for purpose. Comparison of the guide with experts' practices offered additional perspectives on what building diagnosis should entail. The pilot project produced rich and high-quality data that will nurture the evolution of the guide. The project demonstrated both the viability and the utility of applying the citizen science approach to radon post-measurement phases, with measurable benefits in bridging knowledge gaps and in encouraging behavioural changes. The results of using a citizen science approach in the field of radon management and research are encouraging, and they far outweigh the challenges involved in the implementation.

Ethical impact of suboptimal referrals on delivery of care in radiology department

The referral is the key source of information that enables radiologists and radiographers to provide quality services. However, the frequency of suboptimal referrals is widely reported. This research reviews the literature to illuminate the challenges suboptimal referrals present to the delivery of care in radiology departments. The concept of suboptimal referral includes information, that is; missing, insufficient, inconsistent, misleading, hard to interpret or wrong. The research uses the four ethical principles of non-maleficence, beneficence, Autonomy and Justice as an analytic framework.Suboptimal referrals can cause harm by hindering safe contrast-media administration, proper radiation protection by justification of procedures, and compassionate patient care. Suboptimal referrals also hinder promoting patient benefits from the correct choice of imaging modality and protocol, an optimal performed examination, and an accurate radiology report. Additionally, patient autonomy is compromised from the lack of information needed to facilitate benefit-risk communication. Finally, suboptimal referrals challenge justice based on lack of reasonable patient prioritising and the unfairness caused by unnecessary examinations.These findings illuminate how suboptimal referrals can inhibit good health and well-being for patients in relation to safety, missed opportunities, patient anxiety and dissatisfaction. The ethical challenges identified calls for solutions. Referral-decision support tools and artificial intelligence may improve referral quality, when implemented. Strategies addressing efforts of radiology professionals are inevitable, including gatekeeping, shared decision-making and inter-professional communication; thereby raising awareness of the importance of good referral quality and promoting commitment to ethical professional conduct.

CZECH RADIOGRAPHERS' PERCEPTION OF ETHICAL ASPECTS OF RADIOLOGICAL PROTECTION

This study assessed the perception of ethics by 40 radiographers and 30 radiography students in the Czech Republic. Most respondents confirmed that they considered the topic to be important for their profession. The majority of radiographers, but only few students, had encountered some ethical dilemma during their work. Almost all were aware of the existence of a Code of Ethics for radiographers, and the majority had at least some ethics education during their professional training. Our findings differ from those of similar surveys in the USA published in 2013 and 2015. In these, two-thirds of the respondents stated that they had not received any instruction in ethics during their training, and one-third indicated that they had witnessed unethical behaviour in their profession. We conclude that the ethics education of Czech radiographers makes them more aware of ethical problems when they encounter them.

ICRP PUBLICATION 152 Approved by the Commission in November 2021

Radiation detriment is a concept developed by the International Commission on Radiological Protection to quantify the burden of stochastic effects from low-dose and/or low-dose-rate exposures to the human population. It is determined from the lifetime risks of cancer for a set of organs and tissues and the risk of heritable effects, taking into account the severity of the consequences. This publication provides a historical review of detriment calculation methodology since ICRP Publication 26, with details of the procedure developed in ICRP Publication 103, which clarifies data sources, risk models, computational methods, and rationale for the choice of parameter values. A selected sensitivity analysis was conducted to identify the parameters and calculation conditions that can be major sources of variation and uncertainty in the calculation of radiation detriment. It has demonstrated that sex, age at exposure, dose and dose-rate effectiveness factor, dose assumption in the calculation of lifetime risk, and lethality fraction have a substantial impact on radiation detriment values. Although the current scheme of radiation detriment calculation is well established, it needs to evolve to better reflect changes in population health statistics and progress in scientific understanding of radiation health effects. In this regard, some key parameters require updating, such as the reference population data and cancer severity. There is also room for improvement in cancer risk models based on the accumulation of recent epidemiological findings. Finally, the importance of improving the comprehensibility of the detriment concept and the transparency of its calculation process is emphasised.© 2022 ICRP. Published by SAGE.

The Effort for Radiation Protection Increases the Value of Interventional Radiology

Radiation protection is one of the most essential efforts for radiologists. The newest update of medical radiation protection in Japan focused on the field of interventional radiology. In this situation, it is required to choose for interventional radiologists to participate in it reluctantly or proactively. To enhance the value of interventional radiology in society, our effort of commitment to learning, collaborating, and assuming our awesome responsibility is requested. We will contribute to the safety of medical facilities and society.

Justification of dose limits-historical development, ethical basis, and the way forward

The dose limits recommended by the International Commission on Radiological Protection have undergone considerable changes in the course of the past 90 years, and different arguments have been put forward for their justification. This has been largely due to new insights of radiation research, but changing perceptions of the related ethical values have also played a role. The current paper reviews important stages in this development and attempts to derive some implications for the Commission's next general recommendations. Above all, it suggests that it is essential to present clear and consistent justification strategies for dose limits (and related values), compatible with the core values of the system of radiological protection, especially prudence and justice.

The three R's of reasonable in radiological protection: relationships, rationale, and resources

Central to applying the principle of optimisation in the system of radiological protection is the evaluation of what level of radiation exposure should be considered 'as low as reasonably achievable' (ALARA), after taking into account the prevailing circumstances. Determining what is 'reasonable' is an abstract, although somewhat intuitive concept with many potential interpretations depending on both the situation and those involved, whether individuals or organisations. There are common themes in the types of considerations that need to be addressed to determine 'reasonableness' regardless of the exposure situation. However, despite the consistent and agreeable nature of these themes, there remains a gap in how to apply them in real situations. For example, without measurable goalposts (or a clear process for setting such goalposts) for determining what constitutes ALARA, we can find ourselves misinterpreting the optimisation process as keeping exposures 'as low as possible'. We propose herein, by consolidating and building on existing ideas, an easily understandable and actionable 'reasonableness' framework. This simple, yet broadly applicable tool is intended to help radiation protection experts in the systematic, deliberative, and collaborative reflection on all of the factors that make up 'reasonable' before making a decision-whether it be a proposed medical treatment or clean-up of a contaminated site. Each process execution and decision itself will necessarily retain the complexity of the prevailing circumstance. The proposed 'Rs' of Reasonable represent Relationships (stakeholders, empathy, and trust), Rationale (contextual, technical, and ethical), and Resources (technological, financial, and time).

Women in radiation (WiR)-a perspective for the strengthening of radiation protection

Gender balance refers to the equitable treatment and access to opportunities for all genders. In order to achieve true gender balance, a variety of proactive approaches developed collaboratively, with insight from multiple perspectives, need to be implemented. With that purpose, the participation of women in professions related to radiation and radiation protection was prioritised and given high visibility by allocating a 'Women in Radiation' (WiR) Special Session at the 15th International Congress of the International Radiation Protection Association (IRPA), hosted by South Korea on 20 January 2021. In this session, various issues related to gender balance and equity/equality were highlighted by the panellists, and further elaborated in a subsequent discussion with attendees. The main goal of the WiR Special Session was to convene women from different organisations, career and age stages, disciplines and countries, in particular to consider the Asian-Oceanic vision and status of gender equality, along with other topics to support a 'Call for Action', with concrete recommendations subsequently provided to IRPA. The discussion stressed the main needs and challenges faced by women working in various radiation fields, along with raising awareness of possible professional and employment opportunities. This paper identifies some steps necessary to encourage, enhance and support the inclusion of more diversity in nuclear professions with specific emphasis on women. In conclusion, gender balance and equality must be at the heart of any strategic plan for the future of the radiological protection profession; international cooperation between relevant bodies is essential for success and could serve as a catalyst for specific policy statements aimed at achieving a balanced representation of women in radiological protection.

The role of empathy in ethics of radiological protection

Radiological protection is often considered a matter of scientific and technological facts only, not of value judgements. This perception is now gradually changing, especially with ICRP Publication 138, which addressed the ethical foundation of the system of radiological protection. It identified values which have guided the Commission's recommendations over the decades, but have not always been made explicit. Four core values are discussed (beneficence/non-maleficence, prudence, justice, dignity) as well as three procedural values (accountability, transparency, inclusivity). The latter are considered critical to the practical implementation of the system of radiological protection. Here we are exploring empathy as a procedural values complementing the three identified in ICRP Publication 138. Empathy can be defined as the 'capability (or disposition) to immerse oneself in and to reflect upon the experiences, perspectives and contexts of others'. It is often understood as a skill that one either has or has not, but research has shown it can be taught and therefore can be required as an attitude of those working in health care, education, design, and technology. We suggest it is an essential prerequisite to the assessment and management of any radiological situation and the health problems accruing from it. The concerns of people affected, their needs and wishes need to be taken seriously from the very beginning of any decision-making process. Even if they are considered unfounded and exaggerated, the insights they provide will be valuable for the understanding of the overall situation. Without empathy, our practice of beneficence and non-maleficence as well as solidarity would be oddly limited.

Radiographers' actions and challenges when confronted with inappropriate radiology referrals

OBJECTIVES

To explore radiographers' actions toward inappropriate referrals and hindrances to assessing referrals.

METHODS

An online survey was distributed to radiographers via the International Society of Radiographers and Radiological Technologists (ISRRT) networks. The questionnaire consisted of 5-point Likert scale questions on radiographers' actions to supplement referral information, actions for unjustified referrals and hindrances to referral assessment. The questionnaire was validated using a test-retest reliability analysis. Kappa values ≥ 0.6 were accepted. SPSS software was used for data analysis and chi-square tests to compare subgroups.

RESULTS

Total responses received were 279. The most reported actions to supplement missing referral information were to ask the patient or relative, examine the body region of concern and check medical records (73%, 70%, 67%, responded often/always, respectively). The actions when confronted with unjustified referrals were reported equally to consult the radiologist, referring clinician and radiographer (69-68% often/always responses). The hindering factors ranked high (agreed/strongly agreed responses) pertained to inadequate information in referral forms (83%), ineffective communication among healthcare professionals (79%), lack of training (70%) and allocated time (61%). Statistically significant associations were observed for a few actions and hindrances with education level, modality of practice and responsibility to screen imaging referrals.

CONCLUSION

Radiographers consult colleagues about suspected unjustified referrals. Effective communication pathways, training and time allocation to improve radiographers' skills to assess referrals may enhance appropriate imaging and delivery of quality patient care.

KEY POINTS

• Radiographers' actions of supplementing missing information in radiology referrals facilitate provision of high-quality health services. • Radiographers' strategy when confronted with inappropriate referrals is to consult radiologists and referring clinicians. • Better inter-professional communication and organisation of tasks can facilitate radiographers' participation in referral assessment to ensure appropriate imaging.

Areas of research to support the system of radiological protection

This document presents the ICRP's updated vision on "Areas of Research to Support the System of Radiological Protection", which have been previously published in 2017. It aims to complement the research priorities promoted by other relevant international organisations, with the specificity of placing them in the perspective of the evolution of the System of Radiological Protection. This document contributes to the process launched by ICRP to review and revise the System of Radiological Protection that will update the 2007 General Recommendations in ICRP Publication 103.

Does radiology require informed consent for radiation risk?

Recent trends in medical decision-making have moved from paternalistic doctor-patient relations to shared decision-making. Informed consent is fundamental to this process and to ensuring patients' ongoing trust in the health-care profession. It cannot be assumed that patients consent to the risk associated with medical exposures, unless they have been provided with the information to make that decision. This position is supported by both the legal and ethical framework around Radiation Protection detailed in this commentary.

Why is radiological protection different in medicine? Sievert Memorial Lecture

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.

An ethical dimension to accident management and health surveillance

Many radiation protection actions carry a multitude of direct and indirect consequences that can impact on the welfare of affected populations. Health surveillance raises ethical challenges linked to privacy and data protection, as well as questions about the net benefit of screening. The SHAMISEN project recognized these issues and developed specific recommendations to highlight ethical challenges. Following a brief overview of ethical issues related to accident management, this paper presents the SHAMISEN recommendations: R1 The fundamental ethical principle of doing more good than harm should be central to accident management; and R4 Ensure that health surveillance respects the autonomy and dignity of affected populations, and is sensitive to any inequity in the distribution of risks and impacts. While a holistic approach to accident management means that decisions will be complicated by different values, perceptions and uncertainties about outcomes, addressing ethical issues could help ensure that the assumptions and potential conflicts behind eventual decisions are as transparent as possible.

Supporting societal and economic dynamics of recovery: lessons from Chernobyl and Fukushima

This paper does not necessarily reflect the views of the International Commission on Radiological Protection.Beyond the consideration of radiological aspects, the rehabilitation of living and working conditions after a large nuclear accident is a complex process in which all dimensions of individual and community life are involved and interconnected. Responsibles of socio-economic entities are facing various difficulties/challenges, including the implementation of protective actions for ensuring the protection of employees, the continuity of production of good-quality products in affected areas, and restoring the confidence of consumers. For affected local communities, the deployment of a socio-economic programme is essential to enable a sustainable future while recognising that a return to the pre-accident situation is generally not achievable. In this context, supporting the societal and economic dynamics of the recovery process requires the adoption of specific governance mechanisms respecting a series of ethical and social values, as highlighted by lessons from the post-accident management of the Chernobyl and Fukshima accidents at Chernobyl and Fukushima Daiichi nuclear power plants.

Old enemy, new threat: you can't solve today's problems with yesterday's solution

The radiation protection principles of justification, optimization, and dose limitation as enumerated by the International Commission on Radiological Protection have been guiding light for the profession for over three decades. The dose limitation does not apply to medical exposure but keeping patients' doses low is achieved through optimization, particularly by developing and using diagnostic reference levels (DRLs). There are new findings that demonstrate that despite using the best possible approaches to justification and optimization including as well use of DRLs, a very large number of patients are receiving doses in excess of 100 mSv of effective dose or organ doses exceeding 100 mGy. A non-ignorable fraction of patients is receiving such high doses in a single day. The magnitude of such patients creates the need for a relook into the principles with the intent to understand what can be done to attend to today's problems. A look at other areas such as approaches, and principles used in the pharmaceutical industry and in traffic management throws some light into what can be learnt from these examples. It appears that the system needs to be enriched to deal with the protection of the individual patient. The currently available approaches and even the principles are largely based on the protection of the population or group of patients. The third level of justification for individual needs further refinement to take into account series of imaging many patients are needing, and cumulative radiation doses involved, many of which happen in a short duration of 1 to 5 years. There is every likelihood of patient radiation doses continuing to increase further that underscores the need for timely attention. This paper provides several suggestions to deal with the situation.

Disproportionate Impacts of Radiation Exposure on Women, Children, and Pregnancy: Taking Back our Narrative

Narratives surrounding ionizing radiation have often minimized radioactivity's impact on the health of human and non-human animals and the natural environment. Many Cold War research policies, practices, and interpretations drove nuclear technology forward by institutionally obscuring empirical evidence of radiation's disproportionate and low-dose harm-a legacy we still confront. Women, children, and pregnancy development are particularly sensitive to exposure from radioactivity, suffering more damage per dose than adult males, even down to small doses, making low doses a cornerstone of concern. Evidence of compounding generational damage could indicate increased sensitivity through heritable impact. This essay examines the existing empirical evidence demonstrating these sensitivities, and how research institutions and regulatory authorities have devalued them, willingly sacrificing health in the service of maintaining and expanding nuclear technology (Nadesan 2019). Radiation's disproportionate impacts should now be the research and policy focus, as society is poised to make crucial and long-lasting decisions regarding climate change mitigation and future energy sources (Brown 2019b).

Effect of protective glasses on radiation dose to eye lenses during whole breast irradiation

OBJECTIVES

The efficacy of radiotherapy for breast cancer has greatly improved owing to better irradiation methods. Radiotherapy aims to deliver therapeutic doses to predetermined target volumes while sparing surrounding healthy tissues. However, there are few reports on radiation exposure to eye lenses, and the recommended exposure limits to ocular lens have been substantially reduced in recent years. This study aimed to investigate the amount of radiation exposure to eye lenses using optically stimulated luminescence dosimeters (OSLDs) and determine whether wearing special protective devices to protect the eyes, as an organ at risk, during whole breast irradiation, is necessary.

METHODS

This experiment used OSLDs on water-equivalent phantom to measure the change in scattered radiation dose due to the difference of irradiation field while using 4- and 6-MV photons of TrueBeam linear accelerator. Using a total treatment dose of 50 Gy, a target was positioned to approximate the breast, and a plan was formulated to deliver 2 Gy per treatment by tangential irradiation. The mean (SD) irradiation dose at the lens position outside the irradiation field was reported.

RESULTS

The scattered radiation dose outside the irradiation field was more affected by the irradiation field size than by the radiation energy. The out-of-field irradiation dose with a larger field of view was higher than that with a smaller field of view. The use of 0.07- and 0.83-mm-thick lead shield protective glasses reduced the radiation dose by 56.1% (P < .001) and 55.6% (P < .001), respectively.

CONCLUSIONS

In this experimental model, the amount of radiation the eye was exposed to during whole breast irradiation was determined by the distance of the eye from the radiation field edge and by wearing protective glasses. In clinical practice, the protection offered by eyeglasses may reduce the risk of long-term side effects and allow the use of higher intensive radiotherapy.

Justification and optimization of radiation exposures: a new framework to aggregate arbitrary detriments and benefits

Myriad radiation effects, including benefits and detriments, complicate justifying and optimizing radiation exposures. The purpose of this study was to develop a comprehensive conceptual framework and corresponding quantitative methods to aggregate the detriments and benefits of radiation exposures to individuals, groups, and populations. In this study, concepts from the ICRP for low dose were integrated with clinical techniques focused on high dose to develop a comprehensive figure of merit (FOM) that takes into account arbitrary host- and exposure-related factors, endpoints, and time points. The study built on existing methods with three new capabilities: application to individuals, groups, and populations; extension to arbitrary numbers and types of endpoints; and inclusion of limitation, where relevant. The FOM was applied to three illustrative exposure situations: emergency response, diagnostic imaging, and cancer radiotherapy, to evaluate its utility in diverse settings. The example application to radiation protection revealed the FOM's utility in optimizing the benefits and risks to a population while keeping individual exposures below applicable regulatory limits. Examples in diagnostic imaging and cancer radiotherapy demonstrated the FOM's utility for guiding population- and patient-specific decisions in medical applications. The major finding of this work is that it is possible to quantitatively combine the benefits and detriments of any radiation exposure situation involving an individual or population to perform cost-effectiveness analyses using the ICRP key principles of radiation protection. This FOM fills a chronic gap in the application of radiation-protection theory, i.e., limitations of generalized frameworks to algorithmically justify and optimize radiation exposures. This new framework potentially enhances objective optimization and justification, especially in complex exposure situations.

Establishing mechanisms affecting the individual response to ionizing radiation

Purpose: Humans are increasingly exposed to ionizing radiation (IR). Both low (<100 mGy) and high doses can cause stochastic effects, including cancer; whereas doses above 100 mGy are needed to promote tissue or cell damage. 10-15% of radiotherapy (RT) patients suffer adverse reactions, described as displaying radiosensitivity (RS). Sensitivity to IR's stochastic effects is termed radiosusceptibility (RSu). To optimize radiation protection we need to understand the range of individual variability and underlying mechanisms. We review the potential mechanisms contributing to RS/RSu focusing on RS following RT, the most tractable RS group.Conclusions: The IR-induced DNA damage response (DDR) has been well characterized. Patients with mutations in the DDR have been identified and display marked RS but they represent only a small percentage of the RT patients with adverse reactions. We review the impacting mechanisms and additional factors influencing RS/RSu. We discuss whether RS/RSu might be genetically determined. As a recommendation, we propose that a prospective study be established to assess RS following RT. The study should detail tumor site and encompass a well-defined grading system. Predictive assays should be independently validated. Detailed analysis of the inflammatory, stress and immune responses, mitochondrial function and life style factors should be included. Existing cohorts should also be optimally exploited.

Ethical considerations related to radiosensitivity and radiosusceptibility

Purpose: The potential for individual radiosensitivity and radiosusceptibility testing, both in clinical practice and in systems of radiological protection, raises complex ethical considerations which must be addressed both in relation to the scientific research looking at the issues themselves, and in relation to any systems of safety and protection which are then proposed for introduction.Methods: This paper uses ethical principles for radiological protection derived by the ICRP together with other biomedical principles, to identify and evaluate some of the ethical issues associated with radiosensitivity testing.Results and conclusions: Although the evaluation is not exhaustive, it illustrates a range of different ethical aspects that would need to be considered, prior to making recommendations for how the field might better address these challenges in its future development.

Clinical and epidemiological observations on individual radiation sensitivity and susceptibility

Purpose: To summarize existing knowledge and to understand individual response to radiation exposure, the MELODI Association together with CONCERT European Joint Programme has organized a workshop in March 2018 on radiation sensitivity and susceptibility.Methods: The workshop reviewed the current evidence on this matter, to inform the MELODI Strategic Research Agenda (SRA), to determine social and scientific needs and to come up with recommendations for suitable and feasible future research initiatives to be taken for the benefit of an improved medical diagnosis and treatment as well as for radiation protection.Results: The present paper gives an overview of the current evidence in this field, including potential effect modifiers such as age, gender, genetic profile, and health status of the exposed population, based on clinical and epidemiological observations.Conclusion: The authors conclude with the following recommendations for the way forward in radiation research: (a) there is need for large (prospective) cohort studies; (b) build upon existing radiation research cohorts; (c) use data from well-defined cohorts with good exposure assessment and biological material already collected; (d) focus on study quality with standardized data collection and reporting; (e) improve statistical analysis; (f) cooperation between radiobiology and epidemiology; and (g) take consequences of radiosensitivity and radiosusceptibility into account.

Translating science into recommendations: the development of NCRP Report No. 180

The development of new recommendations for radiological protection is a complex process of translating scientific knowledge of radiation risks into a coherent system for protection, using experience and ethical values. From 2014 to 2019, the US National Council on Radiation Protection and Measurements (NCRP) engaged in the development of updated recommendations to replace those previously published in 1993. This process included considering the experiences gained with implementation of the NCRP recommendations, and the recommendations of the International Commission on Radiological Protection. The new recommendations, now published as NCRP Report No. 180, go beyond the previous recommendations of the ICRP and NCRP, providing new approaches to emergency response and protection of the environment, covering additional topics not previously addressed in medical exposure. The system of protection continues to rely on justification of actions, optimisation of protection, and use of individual dose criteria to achieve the best protection for each exposure situation. For the first time in general recommendations, ethical values are discussed, and their use in complex decision making to achieve sustainable and supportable decisions outlined. The importance of stakeholder engagement is highlighted, as is the relationship with a radiation protection and safety culture. This paper outlines some of the questions and considerations that were part of the development of NCRP Report No. 180.

Overdiagnosis and overimaging: an ethical issue for radiological protection

AIMS AND OBJECTIVES

This study aimed to analyse the key factors that influence the overimaging using X-ray such as self-referral, defensive medicine and duplicate imaging studies and to emphasize the ethical problem that derives from it.

MATERIALS AND METHODS

In this study, we focused on the more frequent sources of overdiagnosis such as the total-body CT, proposed in the form of screening in both public and private sector, the choice of the most sensitive test for each pathology such as pulmonary embolism, ultrasound investigations mostly of the thyroid and of the prostate and MR examinations, especially of the musculoskeletal system.

RESULTS

The direct follow of overdiagnosis and overimaging is the increase in the risk of contrast media infusion, radiant damage, and costs in the worldwide healthcare system. The theme of the costs of overdiagnosis is strongly related to inappropriate or poorly appropriate imaging examination.

CONCLUSIONS

We underline the ethical imperatives of trust and right conduct, because the major ethical problems in radiology emerge in the justification of medical exposures of patients in the practice. A close cooperation and collaboration across all the physicians responsible for patient care in requiring imaging examination is also important, balancing possible ionizing radiation disadvantages and patient benefits in terms of care.

A critical evaluation of the NCRP COMMENTARY 27 endorsement of the linear no-threshold model of radiation effects

Regulatory policy to protect the public and the environment from radiation is universally based on the linear, no-threshold model (LNT) of radiation effects. This model has been controversial since its inception over nine decades ago, and remains so to this day, but it has proved remarkably resistant to challenge from the scientific community. The LNT model has been repeatedly endorsed by expert advisory bodies, and regulatory agencies in turn adopt policies that reflect this advice. Unfortunately, these endorsements rest on a foundation of institutional inertia and numerous logical fallacies. These include most significantly setting the LNT as the null hypothesis, and shifting the burden of proof onto LNT skeptics. Other examples include arbitrary exclusion of alternative hypotheses, ignoring criticisms of the LNT, cherry-picking evidence, and making policy judgements without foundation. This paper presents an evaluation of the National Council on Radiation Protection and Measurements' (NCRP) Commentary 27, which concluded that recent epidemiological studies are compatible with the continued use of the LNT model for radiation protection. While this report will likely provide political cover for regulators' continued reliance on the LNT, it is a missed opportunity to advance the scientific discussion of the effects of low dose, low dose-rate radiation exposure. Due to its Congressionally chartered mission, no organization is better positioned than the NCRP to move this debate forward, and recommendations for doing so in future reviews are provided.