Abstract
Initially concerned with the application of ionising radiation in medicine, radiological protection has subsequently gone through many phases, and the framework developed by the Commission has evolved continually to embrace other categories of exposure and novel exposure situations. For much of the Western world, medicine is now again the principal source of additional exposures for humans, and it has therefore been the subject of considerable attention in recent years, particularly because the techniques used are advancing so rapidly. What often comes as a surprise, however, is that virtually all of these techniques are being applied increasingly in the field of veterinary medicine. Some advances, such as the use of digital radiography, are to be expected, but the use of computed tomography scanners is increasing enormously, particularly with more second-hand equipment becoming available. The whole gamut of techniques used, from interventional radiology to nuclear medicine, including unsealed source therapy as well as brachy- and teletherapy, are now also applied in veterinary practice. Nevertheless, it may still be easy to consider that the subject of radiation exposure in this field is little different from that of human medical practice, given that the equipment is much the same. However, that would be a mistake for a number of reasons.
Although the protection of humans in the context of veterinary practice is certainly included in the Commission’s current radiological protection system, there are important features that need to be considered separately, and in some depth. Amongst the many practical considerations are the physical circumstances in which animals, particularly large animals, are examined or treated. These can pose unique challenges and risks for the professional staff involved, as well as ancillary personnel and members of the public, including animal owners and handlers. Some procedures applied to animals, such as positron emission tomography scans, may result in higher doses to staff compared with human medical practice. Also, when working with radioactive materials, persons not actually present during the procedures may subsequently be exposed or become contaminated. However, the principal difference is, of course, the fact that the patient is an animal, and thus different criteria may well apply, particularly with regard to decision making and the knowledge base upon which such decisions are made.
The Commission has already extended its remit to address issues beyond that of the protection of humans alone (ICRP, 2003, 2007a, 2008, 2014), but this has been concerned with the protection of animals at a population level in an environmental context, whereas in the case of veterinary practice, the focus is on the protection of an individual animal in a clinical context. Bearing in mind that the Commission has always acknowledged that its guidance with regard to medical practice has, of necessity, been somewhat different from that relating to other categories of exposure, the fact that the patient in the case of veterinary practice is an animal also raises fundamental issues with regard to the principles of justification and optimisation, and these, in turn, inevitably spill over into the realm of morals and ethics relating to the health and well-being of that animal.
This issue is not entirely new; it has been raised more than once in the past, but usually addressed by way of somewhat bland and generalised remarks, and without any specific advice forthcoming. The issue was therefore raised yet again, in specific detail, a few years ago (Pentreath, 2016) and, to its credit, the Commission responded quickly (Clement, 2018) by announcing that a specific task group (Task Group 107) was to be established to address the subject of the protection of animals as patients in veterinary practice within the context of the Commission’s remit, and that it was to deliver a report to the Main Commission within a matter of months. This it did.
The resultant report (Pentreath et al., 2020) drew attention to a large number of issues that were of both a scientific and non-scientific nature. These included specific issues relating to quantities and units – an ongoing problem with regard to dosimetry for both animals and plants – as well as issues relating to diagnostic and therapeutic procedures in veterinary practice, many of which are complex and will require some considerable effort to address. The principal advice, however, was first to consider veterinary practice as a whole, including, specifically, the care of the patient, and thus to produce an over-arching document as a parallel to that of Publication 105 (ICRP, 2007b), which considers all of the general issues with respect to radiological protection in human medical practice.
This has now been achieved by way of Task Group 110 reporting to the Commission via Committees 3 and 4. Their publication is thus intended for a wide-ranging audience – including radiological protection professionals, veterinary staff, students, providers of education and training, as well as interested members of the public – to serve as an introduction to the issues surrounding radiological protection in veterinary practice. It is therefore inevitably something of a hybrid publication that contains much basic information familiar to radiological protection professionals, but because the protection of animals as patients has not been discussed previously, it also contains material that may be new to them. Indeed, it dwells upon the topics of justification and optimisation in veterinary practice, and the current ethical views that relate to them, at some length. For all aspects of the subject, it sets the scene for more detailed guidance to follow in the future. It is, therefore, another ‘foundation document’ following in the wake of the Commission’s 2007 Recommendations (ICRP, 2007a).
However, there is still much to be done. One area that was immediately apparent to both task groups was the inadequacy of information on all aspects of the subject at international level. In view of the rapid growth of the use of ionising radiation in both diagnostic and therapeutic veterinary practice, the availability of more equipment, and a rising demand by members of the public for the highest possible care and treatment of their animals, it is to be hoped that this publication will stimulate a greater interest in the compilation of relevant data across all aspects of the subject.
Finally, it surely makes sense to view the subject of the exposure to radiation and its consequences on all animals, particularly mammals, in a collective way, and to consider how this knowledge can be used for the protection of humans and animals in different exposure situations. There are data that can only arise from experience with animals that could be of value to improve human radiological protection, and vice versa, but these data are only likely to arise within a framework that has a sound numerical basis. There is so much that could be learned from each other, and the combined data arising would be highly beneficial to all.