D’une « nouvelle sorte de rayonnement » à la tomodensitométrie : une histoire du scanner

In this article, the authors present the evolution of radiology, from the discovery of X-rays until the invention of the CT scan. Since the invention of X-rays by W.C. Röntgen, the search for the third dimension in medical imaging has provided a lot of developments both in physics and in mathematics. This third dimension has finally occurred in the early 1970s when CT was put forward by G.N. Hounsfield. This paper places the developments in their historical context.     

Reflections on the impact of advances in the assessment of genetic risks of exposure to ionizing radiation on international radiation protection recommendations between the mid-1950s and the present

Efforts at protecting people against the harmful effects of radiation had their beginnings in the early 1900s with the intent of protecting individuals in medicine and associated professions. Such efforts remain vital for all of us more than 100 years later as part of our 'learning to live with ionizing radiation.' The field of radiation protection has evolved slowly over time with advances in knowledge on hereditary (i.e., genetic) and carcinogenic effects of radiation continually improving our ability to make informed judgments about how best to balance risks against benefits of radiation exposure. This paper examines just one aspect of these efforts, namely, how advances in knowledge of genetic effects of radiation have impacted on the recommendations of the International Commission on Radiological Protection (ICRP). The focus is on the period from the mid-1950s (when genetic risk estimates were first made) to 2007. This article offers a detailed historical analysis and personal perspective, and concludes with a synopsis of key developments in radiation protection.     

Wilhelm Conrad Röntgen: The scientist and his discovery

Röntgen’s discovery of a new type of radiation is the epochal event in a series of highlights of physics emerging within only a few decades of the late 19th century. As these discoveries are directly or indirectly rooting in the study of the phenomenon of electric discharge in gases a brief look at the physics scenario in the immediate pre-X-ray era is presented in the first section. Rather than just the fortune with the bold it is Röntgen’s character as a diligent, self-critical and ingenious scientist which made his discovery possible. This will be illustrated in the sections on Röntgen’s personal life and some specific details of his experiments leading to the discovery of X-rays. Finally, a short overview is given on the potential and the large variety of applications of X-rays.     

Principal inferences from studies of radiobiological effects for radiation protection purposes

The most recent Recommendations (Publication 103) issued by the International Commission for Radiological Protection (ICRP) are based on the data that have been published since 1990 up to now. The basic task of the ICRP Committee 1 was to formulate the key implications of studies on radiobiological effects for the purposes of radiological protection. Presented in the paper are the new achievements in the field of biology, radiobiology and radiation epidemiology which were taken into account by the ICRP in the process of Publication 103 preparation. The Recommendations provide present-day values of weighting factors for radiation exposure and tissue weighting factors, as well as radiation detriment and radiogenic risk factors for cancer and genetic diseases. Also considered are tissue reactions to radiation exposure, consequences of in utero exposure and the risks of developing non-cancer diseases for exposed individuals. It should be noted that the key inferences and recommendations are to a considerable degree related to biological effects accounted for by acute and chronic exposure to ionizing radiation in the range of small doses (up to 100 mSv).     

Non-stochastic effects: compatibility with present ICRP recommendations

The present recommendations of the ICRP (International Commission on Radiological Protection) are almost entirely based on 'stochastic effects' of ionizing radiation, i.e. cancer induction and heritable effects. In a recent report the compatibility of present recommendations with non-stochastic effects has been considered. The present paper is a summary of these findings.     

The Icelandic genome debate

Three of the central issues in contemporary debates about the commodification of the human body are those of property, ownership, and access. This article uses the case of the central medical database on Icelanders to discuss contesting claims about the ownership of the human genome, with respect to the rapid development of biotechnology, human genome projects and DNA collections. We emphasize the contrast between commercial and communitarian perspectives and to illustrate our argument we explore debates about the Icelandic database. These debates have been intense, focusing on a range of issues, including ethics, academic freedom, public health and, last but not least, the control and ownership of medical records, genetic information and genealogical data. This article should be seen primarily as an anthropological commentary on ongoing developments.     

Dose limits for occupational exposure to ionising radiation and genotoxic carcinogens: a German perspective

This paper summarises the view of the German Commission on Radiological Protection (“Strahlenschutzkommission”, SSK) on the rationale behind the currently valid dose limits and dose constraints for workers recommended by the International Commission on Radiological Protection (ICRP). The paper includes a discussion of the reasoning behind current dose limits followed by a discussion of the detriment used by ICRP as a measure for stochastic health effects. Studies on radiation-induced cancer are reviewed because this endpoint represents the most important contribution to detriment. Recent findings on radiation-induced circulatory disease that are currently not included in detriment calculation are also reviewed. It appeared that for detriment calculations the contribution of circulatory diseases plays only a secondary role, although the uncertainties involved in their risk estimates are considerable. These discussions are complemented by a review of the procedures currently in use in Germany, or in discussion elsewhere, to define limits for genotoxic carcinogens. To put these concepts in perspective, actual occupational radiation exposures are exemplified with data from Germany, for the year 2012, and regulations in Germany are compared to the recommendations issued by ICRP. Conclusions include, among others, considerations on radiation protection concepts currently in use and recommendations of the SSK on the limitation of annual effective dose and effective dose cumulated over a whole working life.     

Radiation protection: the NCRP guidelines and some considerations for the future.

The National Council on Radiation Protection and Measurements (NCRP) in the USA and the International Commission on Radiological Protection (ICRP), worldwide, were formed about 1928 and have since made recommendations on appropriate levels of protection from ionizing radiation for workers and for the public. These recommendations and much of the guidance provided by these organizations have usually been adopted by regulatory bodies around the world. In the case of the NCRP, the levels have fallen from 0.1 roentgen per day in 1934 to the current 5 rem per year (a factor of about 5). The present levels recommended by both the ICRP and the NCRP correspond to reasonable levels of risk where the risks of harm from ionizing radiation are compared with the hazards of other, commonly regarded, as safe, industries. Some considerations for the future in radiation protection include trends in exposure levels (generally downward for the average exposure to workers) and improvements in risk estimation; questions of lifetime limits, de minimis levels, and partial body exposures; plus problems of high LET radiations, acceptability of risk, synergisms, and risk systems for protection.     

Not the doctor’s business: Privacy,personal responsibility and data rights in medical settings

This paper argues that assessing personal responsibility in healthcare settings for the allocation of medical resources would be too privacy-invasive to be morally justifiable. In addition to being an inappropriate and moralizing intrusion into the private lives of patients, it would put patients’ sensitive data at risk, making data subjects vulnerable to a variety of privacy-related harms. Even though we allow privacy-invasive investigations to take place in legal trials, the justice and healthcare systems are not analogous. The duty of doctors and healthcare professionals is to help patients as best they can—not to judge them. Patients should not be forced into giving up any more personal information than what is strictly necessary to receive an adequate treatment, and their medical data should only be used for appropriate purposes. Medical ethics codes should reflect these data rights. When a doctor asks personal questions that are irrelevant to diagnose or treat a patient, the appropriate response from the patient is: ‘none of your business’.     

Ethical Review of Research on Human Subjects at Unilever: Reflections on Governance

This article considers the process of ethical review of research on human subjects at a very large multinational consumer products company. The commercial context of this research throws up unique challenges and opportunities that make the ethics of the process of oversight distinct from mainstream medical research. Reflection on the justification of governance processes sheds important, contrasting light on the ethics of governance of other forms and context of research.     

Implementation of the 1990 recommendations of ICRP in the countries of the European community

The International Commission on Radiological Protection (ICRP) has published new Recommendations in ICRP Publication 60. These 1990 Recommendations provide a System of Radiological Protection that takes account of the most recent information on the effects on health of exposure to ionising radiation and trends in the setting of safety standards. Within the European Community the Recommendations fo the ICRP are implemented through a Euratom Directive which is binding on member states, a draft of which has been accepted by the Article 31 Group and must eventually be ratified by the Council of Ministers. It is expected that the new directive will broadly endorse the principles of protection given in the 1990 Recommendations together with the dose limits for both workers and members of the public. There are likely to be some modifications to the 1990 Recommendations that are mainly related to their practical application. As it will be some time before the directive is incorporated into national regulations, a number of member states have taken independent initiatives. The development of dose constraints for occupational, medical and public exposure is being seen by national organisations in many countries as a significant new approach to improving standards of radiation protection.     

Futility by Any Other Name. The Texas 10 Day Rule

This commentary examines the ethics and law in the United States as they relate to the foregoing of life sustaining treatment when such treatment is deemed medically inappropriate. In particular the article highlights the procedural approach when there is disagreement between physicians and surrogates or patients as exemplified in Texas Law. This approach, although worthy in concept, may in practice invite opposition and dissatisfaction as it may be perceived as coercive and pitting the weak against powerful adversaries and interests, in addition to discouraging the exercise of professional virtues. Too inflexible an approach erodes trust, and furthermore the Texas law allows hospital ethics committees to move from an advisory non judgmental role to a quasi legal court with real legal power but no credentialing or oversight.     

什么是生命伦理学？——从历史发展的视角

生命伦理学是20世纪60年代兴起于美国的一门新兴学科,旨在应对生命科学和生物技术的发展或医疗保健的演变使人类面临的种种伦理难题。生命伦理学的兴起有着特殊的社会历史背景。它在发展过程中出现的一些里程碑式的案例,对生命伦理学的发展产生了深远的影响。从其发展特征上看,生命伦理学和医学伦理学紧密联系,有着更为广泛的研究内容和独特的专业特性。生命伦理学要有效回应现代医学和生命科学的发展给人类带来的伦理难题,既要准确地界定伦理问题,又要以适当的方式将伦理学基础理论应用到具体问题当中。对生命伦理学的基本理论进行概述。     

The Ethics of Engaged Presence: A Framework for Health Professionals in Humanitarian Assistance and Development Work

In this article, we present an ethics framework for health practice in humanitarian and development work: the ethics of engaged presence. The ethics of engaged presence framework aims to articulate in a systematic fashion approaches and orientations that support the engagement of expatriate health care professionals in ways that align with diverse obligations and responsibilities, and promote respectful and effective action and relationships. Drawn from a range of sources, the framework provides a vocabulary and narrative structure for examining the moral dimensions of providing development or humanitarian health assistance to individuals and communities, and working with and alongside local and international actors. The elements also help minimize or avoid certain miscalculations and harms. Emphasis is placed on the shared humanity of those who provide and those who receive assistance, acknowledgement of limits and risks related to the contributions of expatriate health care professionals, and the importance of providing skillful and relevant assistance. These elements articulate a moral posture for expatriate health care professionals that contributes to orienting the practice of clinicians in ways that reflect respect, humility, and solidarity. Health care professionals whose understanding and actions are consistent with the ethics of engaged presence will be oriented toward introspection and reflective practice and toward developing, sustaining and promoting collaborative partnerships.     

Ethical analysis of cadaver supply and usage processes for research within the scope of the Helsinki Declaration

Recent technological developments have considerably transformed the supply, storage, and transportation processes of cadavers, creating new and previously unforeseen ethical challenges regarding cadaver usage. In this study, we analyzed two aspects of the cadaver processing system—cadaver supply and its use in research. Thereafter, we highlighted the major ethical concerns underlying these stages and correlated our search results with the ethical principles outlined in the Declaration of Helsinki (DoH), or Helsinki Declaration. To ensure the reliability and continuity of medical progress, human—especially cadaver—research depends on the ethical priorities as outlined in the DoH: respect for autonomy, privacy/confidentiality, risks/burdens/benefits, and the protection of vulnerable groups. According to our ethics analysis, which also corresponds with the ethics guidelines of the Consensus Panel on Research with the Recently Dead, the most ignored values were respect for autonomy and privacy/confidentiality issues. Based on these ethical concerns, we provide recommendations to address these challenges in anatomy research.     

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.

     

An epidemic like any other? Rights and responsibilities in HIV prevention.

Throughout the 1980s and into the 1990s, HIV prevention has been closely associated with the protection of individual human rights. Traditional public health measures such as compulsory testing and isolation have largely been rejected as ineffective in public health terms and inappropriate in the context of human rights protection. HIV prevention has been based instead chiefly on elective measures --information, education, counselling, and voluntary testing. In the past five years there have been important clinical, epidemiological, and social developments in the AIDS epidemic. These changes, combined with a growing recognition of possible weaknesses inherent in a strictly voluntarist approach to HIV prevention, may herald a new approach to AIDS control which places more weight on social responsibility in the context of HIV prevention.     

Radiation Protection in Canada: Part III. * The Role of the Radiation Protection Division in Safeguarding the Health of the Public

The current status of radiation protection in Canada is discussed in the last of a three-part series. Particular emphasis has been placed on the role of the Radiation Protection Division of the Department of National Health and Welfare. A radioactive fallout study program has been established involving the systematic collection of air and precipitation samples from 24 locations, soil samples from 23 locations, fresh-milk samples from 16 locations, wheat samples from nine areas and human-bone specimens from various hospitals throughout Canada. A whole-body-counting facility and a special study of fallout in Northern areas have also been initiated. For any age group, the highest average strontium-90 concentration in human bone so far reported has been less than four picocuries per gram of calcium compared with the maximum permissible level of 67 derived from the International Committee on Radiation Protection (ICRP) recommendations. By the end of 1963 a general downward trend of levels of radioactivity detected in other parts of the program has been observed. Programs to assess the contribution to the radiation exposure of members of the population from medical x-rays, nuclear reactor operations and natural background-radiation sources have also been described. The annual genetically significant dose from diagnostic x-ray examinations in Canadian public hospitals has been estimated to be 25.8 mrem. Results from the reactor-environment monitoring programs have not suggested the presence of radioactivity beyond that contributed from fallout.     

The identification of potential radiation risk groups in case of chronical occupational exposure: individual cancer risks among the industrial firm "Maiak" personnel

The draft new recommendations of the ICRP emphasize the need for transition from the collective dose to the dose matrix concept with optimization of the radiation protection system. In fact, this means assessment of the attributive (radiation-induced) risk at individual level with allowance for the dynamics of dose accumulation during the whole length of professional experience. The work provides assessments for high potential risk group from the "Mayak" personnel based on the dose matrix and using the UNSCEAR technique for assessing the attributive risk. It was found that about 2% of "Mayak" personnel subject to individual dosimetric monitoring in 2005 can be attributed to this group.     

Latin American healthcare systems in times of pandemic

The COVID‐ 19 pandemic is a critical test for the already overburdened and mostly underfunded public healthcare systems of Latin America. In a region that suffers from severe inequalities, public healthcare systems are the only source of medical care for a large sector of the population who work in the informal economy or are unemployed. State‐run hospitals and clinics are already overstressed by continuous demand for treatment of vector‐borne diseases and community‐acquired infections as well as high rates of non‐communicable diseases. Ideological misconceptions and denial among Latin America’s political leaders prevented timely preparations for the pandemic and added to chronic governance problems. As ethical expertise in Latin America focuses on research ethics, few hospitals in the region have functioning clinical ethics committees or clinical ethics policy, forcing healthcare personnel to make excruciating treatment decisions in an environment dominated by material scarcity and public distrust. This essay examines the emergence of COVID‐19 in Latin America and the serious challenge that it poses for Latin America's public healthcare systems.