Radiological Protection in Veterinary Practice


Draft document: Radiological Protection in Veterinary Practice
Submitted by Sharan Packer, UK Society for Radiological Protection
Commenting on behalf of the organisation

General comments

SRP agrees with the general thrust of this document, reducing environmental dose and the use of justification and optimisation in the protection of animals is to be encouraged. However, it seems disproportionate to  have > 20 pages on the ICRP System of Radiation Protection before addressing veterinary practice in a practical sense. Although aimed at vets, they will take some convincing to read this if they have to wade through so much introduction. Also, any divergence in this document from what ICRP has already written in relation to the system for radiological protection will be confusing. A few pages on what the system is intended to achieve and brief summaries of any differences should be enough, with references to other documents for more detail for those who need it

The 20 pages on application to veterinary practice are clear and potentially useful for those involved in veterinary work or who regulate it, though arguably rather long for the purposes of setting out what should be in the basic training curriculum material. Some aspects, such as the discussion of the absence of data to allow specification of DRLs might be worth publication by the authors of the report in a suitable journal.

As the report highlights, "veterinary applications of ionising radiation, and their ensuing protection challenges, are to a large extent comparable to medical and non-medical human exposure situations and could benefit from similar approaches".

Overall, vets just need clear instructions on how to use ionising radiation safely. That needs to come from national professional bodies and radiation protection advisers that are able to take account of national regulations on ionising radiation.

There is a suggestion that studies on rats could be used to predict radiation effects in humans but not in animals. This suggestion does not seem reasonable.

Are there sufficient studies to state that there is a significant risk of stochastic effects due to general practice veterinary diagnostic radiology? In the larger centres there may be a risk, but shorter life spans appears to mean that changes would not be apparent or quantifiable.

The routine radiography of breeding animals to exclude hip dysplasia has been questioned, particularly the multiple repeats of diagnostic but not “pretty” images, --- good points were made concerning the repeat of images that are diagnostic, (with no justification apart from aesthetics).

The extensive radiography of horses for insurance and pre sale has been driven by buyers / sellers, and the insurance companies, with no clinical justification or value. This is an unnecessary environmental dose, patient dose and dose to the operators, (eye dose could easily approach and exceed the dose limit).

Detailed comments

Abstract,

Lines 100 - 103 - It is very unlikely that members of the public and even veterinary staff, students, education and training providers, would choose to read this document in its current form as it is too long and goes into what may be perceived as unnecessary detail.

Section1 - Why this publication

Para 1, Line 138 - remove the word “beloved” as it is superfluous, over sentimental and is not used in the context of human medical exposures.

Para 3, Lines 144 -146 - This sentence is inaccurate and misleading. Suggest it is replaced with “Digitalisation of imaging is not just increasing the mean number of procedures, it may also increase the mean number of views per procedure resulting in an increase in the radiation dose per procedure.” However it is not clear whether this means radiation dose to the animal being examined/treated or the humans involved in undertaking the procedure. In reality it will apply to both.

Section 2 Introduction

Para 9, Lines 201 - 204 - The same comments as for the Abstract lines 100 - 103 apply.

Paras 14 and 15 - These paragraphs seem to be far too detailed with an excessive number of examples. They could be condensed into one paragraph which summarises that veterinary use of ionising radiation has been in existence since the discovery of x-rays but with limited use until recent years. Figures 2.1 to 2.4 are not really necessary in this general document as they are only of historical interest and could be interpreted as being current acceptable practice which they no longer are. These type of images are better suited to being used in a training environment as examples of poor technique and radiation safety.

Para 16, Line 264 - Suggest replace “for a few reasons” with “for a number of reasons”.

Para 21, Lines 349 - 350 - This sentence emphasises that the primary focus is on protection of humans. However much of the content of the document relates to protection of animals and as demonstrated by Annex C there is a lot of emphasis on “ethics” of veterinary radiological procedures which is somewhat at variance with the primary focus.

Section 3 Basic concepts of radiological protection

The whole of this section is overly complex for veterinary practitioners, goes into too much detail and could be simplified and summarised with references to other publications that contain this information..

Para 31, Line 445. The use of “For example” at the beginning of the sentence implies that the sentence refers to radiotherapy whereas it in fact relates to interventional procedures which are not the same thing. This is confusing so should be deleted and the sentence start with “In interventional procedures…”. Generally the paragraph mixes radiotherapy and interventional procedures in a way which can lead to confusion by changing from one to the other and back again within the paragraph. The two modalities should be separated out for clarity.

Sub section 3.4.2 - Protection against contamination. This section only considers contamination from unsealed sources. Elsewhere in the document reference is made to brachytherapy which uses sealed sources. There is the potential for such sources to be damaged and leak causing contamination. There is also the possibility of such sources being “lost  or stolen” leading to accidental exposures and contamination should they subsequently be damaged. The security of sources should also be included.

Section 4 - Ethics and Values

This section could be shortened and summarised because as indicated previously there appears to be an overemphasis on ethics which may not be necessary.

Section 6 - Application of the system of radiological protection to veterinary practice.

Para 111, - Line 1328: "The main source of veterinary occupational exposure is from diagnostic radiography (UNSCEAR, 2010)." Is this speaking about individual exposure or collective, or both?

Para 133, Line 1587 - Radiation workers should be subject to personal dose 1587 monitoring (where deemed appropriate by risk assessment) add “or required by national legislation”…..

Para 135 - SRP supports R Coates’ comments which have been submitted individually, vis Note that the whole point of a 'holistic perspective' is to take account of the full range of risks, benefits and managerial issues across all relevant considerations, not limited to radiation issues. A perspective that only considers ionising radiation practice is not holistic. Radiation practice must not be considered as a self-contained set, which has been a problem in ICRP thinking in previous considerations. Radiation safety must take its balanced place amongst all other safety considerations, both in the optimisation process and in general management approaches.

Para 136 - Where unsealed radioactive substances are mentioned, there is no mention of design for minimisation of any spread of contamination (including ventilation design) and for ease of decontamination and eventual decommissioning. Similarly there is no mention of design for ease of operation, ergonomics etc  or ease of maintenance.

Para 136, Line 1615  - The phrase ‘safe storage’ is used, secure storage is not mentioned.  Safe implies radiological safety and not necessarily secure. This needs to be clarified. A reference to IAEA Nuclear Security Series No. 11-G (Rev. 1), Security of Radioactive Material in Use and Storage and of Associated Facilities would remedy this omission.

Paras 137 to 139 - Much of this seems to be an attempt to cover what has already been very adequately covered in other publications.  The whole of Section 6.4 could well benefit from quoting IAEA’s GSG7 and reference to safety management publications such as ISO45001 although that may be onerous for small organisations where reference to the UK HSE’s HSG65 may be more proportionate.

Para 139, Lines 1633 to 1635 could easily be construed as encouraging the taking of immediate remedial action(s) before an accident/incident is understood - at least to the extent where immediate can be safely and effectively taken in advance of say a root cause analysis which may take some time and involve delving into management procedures.

Para 140, Lines 1640 and 1641 - This sentence does not make sense as the second part does not tie in with the first. The meaning is unclear so clarification/amendment is needed.

Para 145, Line 1681 - “of” should be inserted between “implementation” and “a quality…”.

Para 146, Line 1687 - Suggest that for clarity “the applications they make” should be replaced with “the ionising radiation modalities they use” or similar.

Para 147, Line 1694 - “The protection principles of justification, optimisation and dose limits should apply in full to veterinary applications”. Presumably the meaning is that dose limits should apply to those occupationally exposed and the general public including the animal owner but not the animals themselves although this is not clear as there is no expansion on the statement about dose limits in the following paragraphs whereas there is expansion of the justification and optimisation principles. Clarification is needed.

Para A5, Reference is made to the responsibilities of the “practitioner” . Is there intended to be a distinction between “radiological practitioner” which is used in the previous paragraph. If there is this is not defined anywhere. For consistency should “practitioner” be replaced by “radiological Practitioner”?

Annex B - The material is presented very clearly with very helpful diagrams, as would be used in a training course. However, is it appropriate to include it in the document ?

Annex C - Vets are aware of practicing within an ethical context. The ethics aspect seems to be overemphasised in this in this document could be thought of as being unnecessary. The recommendations in para 143 and the introduction already cover the ethical aspects. A brief summary is all that it needed for Annex C, if it is to be included. at all.

Collated by Sharan Packer FSRP, CRadP, RPA

Chair SRP Medical Sector Committee


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