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X-rays for medical imaging: Radiation protection, governance and ethics
over 125 years
School of Medicine, Trinity College Dublin, Dublin D02 NW44, Ireland
Starting from Röntgen's discovery and the ﬁrst radiograph of his wife’s hand, the curtain was raised on a new
technique with remarkable possibilities for contributing to human health. While growth in applications pro-
ceeded rapidly, it was accompanied by signiﬁcant harms to those involved and by inappropriate opportunistic
application. This paper places the attempts to deal with the harms and inappropriate activities side by side with
the positive developments. It attempts a narrative on the development of medical radiation protection over the
125-year period and places it in the context of a commentary on governance and ethics. The substance of the
narrative is based on the recommendations of ICRP as they developed and altered over time. The governance
commentary is based on assessing the independence of ICRP and its attention to medical exposures. In terms of
ethics, the recommendations at each stage are reviewed in the light of values that are deemed appropriate to
both medical ethics and radiation protection. The paper, while celebrating Röntgen-125, also hopefully provides
a perspective for discussion as ICRP’s centenary in 2028 approaches. This is an important part of ensuring
continued acceptance and conﬁdent use of X-Rays, and helps underwrite the possibility of further developments
in the area.
‘Radiological protection relies on scientiﬁc knowledge, ethical con-
siderations, and practical experience.’ (ICRP 138)
‘All professions are conspiracies against the laity’ (George Bernard
Shaw in The Doctor’s Dilemma)
1. Introduction and background
Roentgen’s 1895 discovery brought great new possibilities to med-
icine. Like most innovation, the good was accompanied by signiﬁcant
harms that were not immediately recognised. This paper is an initial
critical look at the history of the international initiatives to control and
mitigate the harms. These initiatives were often foreshadowed in pro-
gress achieved nationally in, for example, the UK, US, and Germany. In
due course, the international initiatives inﬂuenced development in
most countries throughout the world, following a pattern in which re-
spected international bodies often greatly assist local experts in pro-
gressing initiatives in their own countries. The International
Commission for Radiological Protection (ICRP) is a highly respected
body in radiation protection dating from circa 1928 . Its formal re-
commendations describe the system of radiological protection, provide
ﬁrm statements on what must be achieved to be eﬀective, and are
widely used by governments, the EC, and the UN, among others. The
ICRP website states that the system of radiological protection is based on
the current understanding of the science of radiation exposures and eﬀects,
and value judgements. These value judgements take into account societal
expectations, ethics, and experience gained in application of the system. As
the understanding of the science and societal expectations have evolved over
time, so too has the system of radiological protection . From the com-
mission’s major recommendations, we infer something about radiation
protection, particularly in medicine, at the time they were issued.
As well as a narrative on the ICRP recommendations, the paper
provides a commentary at the end of each period, on how the com-
mission might be viewed from the perspectives of Governance and
Ethics. This is important, as the commission has made much of its in-
dependence. It is also part of understanding how radiation protection in
medicine has gradually evolved and still has signiﬁcant deﬁcits. Early
harms were so damaging and destructive that by the 1930′s a Monument
to the X-ray and Radium Martyrs of All Nations was erected in Hamburg
(Fig. 1) . It is diﬃcult to underestimate the importance of the in-
ternational radiation protection initiatives. Without them to limit and
control the harms associated with Roentgen’s gift to humanity, it is
possible that it might have been side-lined through fear or even aban-
Received 19 August 2020; Received in revised form 5 September 2020; Accepted 13 September 2020
E-mail addresses: firstname.lastname@example.org, email@example.com.
Physica Medica 79 (2020) 47–64
1120-1797/ © 2020 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.
The 125-years since 1895 divides neatly into four periods, A-D, each
of approximately 30 years. During each there have been major devel-
opments, not just in the use of X-Rays, but also in the requirements for
their safe application in medicine and related public health issues. The
periods are taken as notionally: 1895–1928; 1928–1960; 1960–1990;
and 1990 to the present.
1.2. Röntgen, X-Rays and early radiographs (1895–1928)
Wilhelm Röntgen was awarded the 1901 Nobel Prize for his 1895
discovery of X-Rays [3–5]. His reports included the ﬁrst recorded
human radiograph of the hand of his wife, Anna Bertha. A later
radiograph of his friend Albert von Kölliker’s hand is better, as are other
early radiographs arising from a fashion for radiographing family and
friends [3,6]. Röntgen held strong ethical views and did not patent his
ﬁndings, which he felt should be freely available. Likewise, he donated
his Nobel Prize money to research and later rejected an oﬀer of nobility.
He was invited to be an honorary member of the ﬁrst medical X-Ray
organisation, the Röntgen Society in the UK, and declined.
X-Rays were in use across the world for diagnosis and therapy
within a year of Röntgen’s paper. While there were real beneﬁts, sig-
niﬁcant harms to operators and patients were noted. Intuitive protec-
tion measures began to be discussed, although much time had to lapse
before they were considered by professional bodies and it was much
later before they became legally binding. This pattern is often seen;
innovation and development precede formal standards and the law, and
it is important that those charged with responsibility in these areas be
alert to this. The high level of interest in Röntgen’s discovery led to over
1,100 papers on X-Rays in the year following his discovery. The harms,
reported during the following decades, included skin burns, dermatitis,
skin cancers, loss of hair and damage to the eyes [7–9].
Early attempts to provide safety advice, mainly but not only for
workers, included that from Wolfram Conrad Fuchs, in Chicago in
1896, who advised keeping exposures as short as possible and placing
the x-ray tube at least 30 cm from the body. Other workers suggested
ﬁltration of the x-ray beam and the use of collimation. William Rollins,
a Boston dentist, recommended protective tube housings, the use of
leaded glass goggles, collimated beams, and pulsed ﬂuoroscopy. The
suggestions from this period were noted and followed up on by, for
example, the German Röntgen Society (Deutsche Röntgen-Gesellschaft)
and others. The former issued a one-page warning on risks in 1913. The
Röntgen Society (a predecessor of the British Institute of Radiology)
issued rules for X-ray operators and in 1915. In 1921, a British
Committee published a report that provided the basis for the ﬁrst in-
ternational recommendations in 1928, which is considered in Sections
3.2 and 4.1 below [7–9].
Röntgen withdrew early from involvement with medical develop-
ment of his discovery, so further comment on the governance and ethics
of positions taken by him is not necessary here. However, the radio-
graph of his wife’s hand (as opposed to his own) and the early gratui-
tous enthusiasm for hand radiography invites some speculation.
Obviously, by today’s radiation protection standards, such radiographs
would be unacceptable. However, at the time, there was little if any
knowledge of the risk(s) that might be involved. It is also plausible that
it in Röntgen’s case the motivation was a wish to share the limelight (for
which he had little taste) with his wife to whom he was dedicated.
There was also the possibility of a social beneﬁt in persuading people
about the eﬃcacy of the new discovery. Röntgen’s generosity in not
patenting or restricting access to his discovery, and in disposing of his
Nobel Prize monies, were remarkable and it is apparent that he had
many ﬁne qualities [10–13].
2. Materials and methods
The materials used to examine the development of radiation pro-
tection at the international level are, in the ﬁrst instance, the publica-
tions of ICRP and its predecessors since 1928. These are freely available
on the ICRP website on an Open Access (OA) basis . The primary
area of focus is the commission’s formal recommendations. Its other
publications, though not enjoying the same status as the re-
commendations, are also referred to where necessary. Publications from
other supra-national organisations active in radiation protection in
medicine are also accessed, including some from: The Commission of
the European Communities (EC); the International Atomic Energy
Agency (IAEA); the World Health Organisation (WHO); and the Inter-
national Electrotechnical Commission (IEC). Documents from in-
dividual countries or professional bodies are occasionally presented
where they have smething special to oﬀer. The general scientiﬁc lit-
erature is cited in the normal way.
A Governance and Ethics Commentary is provided at the end of each
Fig. 1. Memorial in Hamburg to the Radiology Martyrs, the Physicians, Physicists, Chemists, Technicians, Nurses, and others whose lives were given to the safe use of
the X-ray and Radium rays in medicine .
J. Malone Physica Medica 79 (2020) 47–64
period. It comments on the framework ICRP was working out of, and on
its approach as set out in its recommendations publications. The com-
mentaries contain qualitative judgments made by the author based on
the materials available at the time of writing. The following are con-
sidered when discussing governance:
• Governance is assessed by the presence or absence of conﬂicts of
interest, freedom to act appropriately, independently, and on the
culture of the organisation when it is evident in its publications.
•Governance is also assessed by the extent to which radiation pro-
tection in medicine, speciﬁcally of the patient, is treated in the
• Good practice advice is sometimes considered. The standard for
good practice is that which would be well known and understood by
medical physicists with a good knowledge of the system of radiation
protection as applied in medicine.
The values against which judgments in medical radiation protection
are made are summarised Table 1 and include Dignity/autonomy; ben-
eﬁcence/nonmaleﬁcence; Prudence/precaution; Justice; Honesty/Transpar-
ency; and Solidarity. This is essentially the set proposed by Malone and
Zolzer with the addition of solidarity.
It is particularly well suited to
medical and public health applications and like that adopted by ICRP
for general purposes. It has also been used by WHO [11,13–15].
Brieﬂy, the values are understood as follows :
• Dignity and autonomy: Respect for autonomy is based on human
dignity. It is widely accepted and emphasised in the recent
Declaration of Geneva [10,15]. The balance in emphasis between
dignity and autonomy is diﬀerent in diﬀering cultures.
• Non-maleﬁcence and beneﬁcence: Doing no harm is one of the
central and most cited features of the Hippocratic Oath. So is
working for the good of the patient. Non-maleﬁcence and beneﬁcence
must be balanced. Acceptance of harm has a solid body of precedent
for therapeutic actions, but its place in a diagnosis requires addi-
• Justice: There are many ways of approaching the notion of justice.
In radiation protection, its most signiﬁcant impact is in distribu-
tional justice. It is important for dose limitation, equitable dis-
tribution of risk, and equitable access to resources, including access
to health care.
• Prudence: In screening activities such as mammography, and
medical radiation protection, prudence or precaution assume great
importance. It is found in many written and oral traditions. It has
been embraced by high-level United Nations (UN) conferences as
the appropriate approach to decision-making when data are in-
complete and cause–eﬀect relationships may not be ﬁrmly estab-
lished (e.g. global warming). To paraphrase: where an action may
cause a serious irreversible harm, measures to protect against it must be
taken even when causal relationships are not fully established.
• Honesty/Transparency: Extends well beyond ﬁnancial matters and
includes openness and transparency about beneﬁts and harms. It
requires that people not be nudged, coerced, manipulated, or de-
ceived. Honesty, veracity, and truthfulness are guiding values for
interaction between specialists and lay people exposed to radiation
with its associated probable risks.
•Solidarity: Helps professionals to function in accord with con-
temporary social expectations and thereby strengthens the value set,
where consideration of the common good is important – as it is with
public health – and when community/social considerations arise
The values must be nuanced in application as their varying re-
quirements will inevitably conﬂict with each other and with existing
practices. For example, dignity and autonomy require that the in-
dividual’s preferences be attended to. In practice this can mean that
implicit or explicit consent will be essential for justiﬁcation. In addi-
tion, they may come into conﬂict with the beneﬁcence/non-maleﬁcence
pair. The values also need “speciﬁcation”, i.e. concrete rules or guide-
lines must be derived for diﬀerent areas of application and take due
account of the interests involved.
Of course, there are other dimensions to governance and ethics. For
example, openness to the social sciences, the humanities and indeed the
law are important. These are considered where there is obvious evi-
dence, but the analysis undertaken is constrained by space, material,
and access to records at the time of writing. More research in this area is
3. Period A: Pioneering radiology up to 1928
3.1. Two outstanding radiology pioneers, Marie Curie and Edith Stoney
Many outstanding contributions to various aspects of the early
radiological sciences occurred at the end of the nineteenth century and
during the early part of the twentieth century. As well as Röntgen’s
work, they include the discovery of radioactivity by Becquerel, and the
discovery of the ﬁrst radioactive elements, Polonium and Radium, by
the Curies. However, for a paper in the European Journal of Medical
Physics, the work of two early physics contributors is, perhaps, ap-
propriate. Both Marie Curie and Edith Stoney made major contributions
to the practical development and deployment of radiology during WWI.
At the beginning of WWI Marie Curie put her research on hold, took
her radium stock to the safety of a deposit box in a Bordeaux bank, and
decided to devote herself to the application of radiology in the battle-
ﬁeld in support of the French war eﬀort [19,20]. She was brave beyond
normal, both in the physical sense as well as morally. For her work on
radioactivity, she was awarded the Nobel Prize in 1903, two years after
Röntgen. She took on herself the immense task of organising ﬁeld and
mobile radiology services, bringing Röntgen’s discovery to the French
army at war with Germany. She invented the “radiological car” – a
vehicle containing an X-Ray machine and photographic darkroom
equipment – which could be taken to the front. The electrical power
problem was solved by incorporating a petrol driven generator. Even-
tually she had 20 fully equipped vehicles and trained over 150 women
to staﬀ them. She had her own vehicle that she took to the front,
something that required her to relearn to drive, change ﬂat tires, deal
with accidents, and ﬁx damaged equipment. She also developed up to
200 radiological rooms in ﬁeld hospitals. It is estimated that over one
million examinations of wounded soldiers were performed in her fa-
cilities. Many staﬀ were injured from overexposure. But although it was
known there was a problem, there had been no time to create and en-
force adequate safe practices.
In later life, this was a cause of concern to her. Yet even in the
1920′s neither she nor anybody else was really sure if radium had da-
maged her eyes. Some workers ignored the warning signs and con-
tinued to use it indiscriminately . Her death and associated illness
were often assumed to be associated with her radium work. But she was
unconvinced and tended to attribute her illnesses to X-ray exposure
during the war . She did not acknowledge, with her laboratory
colleagues, the possibility that her deteriorating condition, including
The pragmatic ethics value set used*
Dignity/Autonomy Of the individual
Non-maleﬁcence/Beneﬁcence As in do no harm, do good
Justice As in equity and fairness
Prudence/Precaution As in precautionary principle
Honesty/Transparency As in openness and transparency
Solidarity Sharing risk or resources in the community
Possible additional values under discussion: inclusiveness and empathy
*Adapted from Malone et al., 2019; Malone & Zölzer, 2016 [10,14].
J. Malone Physica Medica 79 (2020) 47–64
cataracts, might be due to radium. Yet, in a less formal setting, being
accompanied home, nearly blind, she wondered aloud if there was a
connection, following British reports of signiﬁcant damage .
Marie Curie was dogged and idealistic, both as a scientist and as a
patriotic humanitarian — if the latter is not an oxymoron. For example,
like Röntgen, she believed humanity should have unfettered access to
her science and she held no patents on use of intellectual property. She
attempted to donate her gold Nobel Prize medals to the war eﬀort, but
the French National Bank refused to accept them . She said:
I am going to give up the little gold I possess. I shall add to this the
scientiﬁc medals, which are quite useless to me. ….. [By] sheer laziness I
had allowed the money for my second Nobel Prize to remain in
Stockholm in Swedish crowns. ….. I should like to bring it back here and
invest it in war loans. The state needs it. Only, I have no illusions: this
money will probably be lost .
The second radiology contributor, Edith Stoney is of Irish origins
and is identiﬁed as the ﬁrst female medical physicist. She also made
remarkable contributions to radiology during WW I on behalf of the UK
[22–24]. She, and her radiologist sister, Florence Stoney worked at the
Royal Free Hospital in London, and oﬀered to provide radi-
ological services on the day war was declared, but their oﬀer was re-
fused as they were women. Edith then took on the task of planning and
operating X-ray facilities for a 250-bed tented hospital in France. She
established stereoscopy to localise bullets and shrapnel and introduced
x-rays to the diagnosis of gas gangrene. This was an important marker
for immediate amputation. She had to retreat several times, but also
established facilities in Serbia and Greece. Here is an impression of
Edith during this period:
A learned scientist, no longer young, a mere wraith of a woman, but her
physical endurance seemed to be inﬁnite; she could carry heavy loads of
equipment, repair electric wires sitting astride ridge tents in a howling
gale, and work tirelessly on an almost starvation diet. And another: Grey
hair, pale blue eyes, very intent on her job, – no special friend – no other
interests, in and out of the x-ray rooms and developing rooms like a
She received many awards from the UK, France, and Serbia. As with
Marie Curie, she was tough, single-minded, demonstrated bravery,
imagination, and resourcefulness in the face of extreme danger. Her
obituaries appeared in publications that few medical physicists reach,
including Nature, The Lancet, The Times of London, and the Australian
3.2. The international congress of radiology
By 1925, radiology was coming of age and held its ﬁrst international
congress (ICR) in London, facilitated by the British Institute of
Radiology (BIR). Thereafter congresses were scheduled every three
years until interrupted by WWII. The London congress resolved to ad-
dress issues that had become matters of major concern among practi-
tioners and their national societies (Section 1.2). They were the pro-
blems of safety, radiation measurement, and professional education for
radiology. The congress established commissions to deal with each of
these that met at the second ICR congress in Stockholm in 1928.
The 1928 congress adopted a set of recommendations to provide
protection against the then known hazards of radiation. The three-and-
a-half-page document, known as International recommendations for X-ray
and radium protection, was produced in English, German and French and
is accessible on an open access basis in the ICRP website [1,25]. This
was the ﬁrst in the series of documents and is the direct predecessor of
ICRP international recommendations. The content of the re-
commendations is dealt with in Section 4.1. The governance, good
practice, and ethics implications of their appearance are addressed in
Sections 3.3 and 4.1 below.
3.3. Governance and ethics commentary
The history of the 1928 recommendations is complex and nuanced
and possibly not fully appreciated by many of those using the re-
commendations of ICRP, including medical physicists. From a govern-
ance perspective, it is important to recognise that they were issued with
the authority of an international medical congress, although not a well-
established one. Training and professional recognition were also a
major concern of the congress. This was an important seminal state-
ment issued by a ﬂedgling body and is the foundation statement for
several professions today. Its importance is that without it, the good
ﬂowing from Röntgen’s discovery might have been greatly attenuated
or possibly side-lined by the increasing burden of harm that was coming
Thus, the recommendations, while commendable in themselves, are
clearly advocacy on behalf of a specialist group. They recall George
Bernard Shaw’s observation at the beginning of this paper, that All
professions are conspiracies against the laity . Here, Shaw is echoing
Adam Smith's much earlier contention that people of the same trade
seldom meet together, even for merriment and diversion, but the conversation
ends in a conspiracy against the public …… . Declaration of conﬂict
(s) of interest is now embedded in scientiﬁc publication, but this was
not so in 1928. The value of the recommendations (Fig. 2) must be
judged with awareness of their origin. This raises an alert, and as will be
seen in Section 4, possibly involves some lack of concern for patients
and the public interest.
From an ethics perspective, the congress had prevention/limitation
of harm from radiology as a major concern. This is consistent with the
Hippocratic Oath which was part of the culture of medicine at the time.
It is also probable that the congress would have been motivated toward
prudence as much was still unknown, and justice to deal eﬀectively with
the known harms. But it is unlikely that the other values in the set
(Table 1) would have ﬁgured strongly.
Both Marie Curie and Edith Stoney made remarkable personal
contributions to radiology during WWI. Both were forces of nature, but
nevertheless experienced gender diﬃculties which did not intimidate
them. They displayed exceptional solidarity. It is possible that neither
allowed prudence to impede a course of action they were determined on.
Both had altruism and a sense of justice to an exceptional extent,
especially Marie Curie in the disposal of her private resources. Neither
was a good communicator, which can undermine honesty, and some of
the diﬃculties they experienced may be related to this. Marie Curie was
not fastidious with radiation protection measures and postponed ad-
dressing them almost indeﬁnitely at great cost to her own health, which
also suggests a problem with honesty. It is possible that Edith Stoney
may have had a more enlightened approach which was beginning to
take hold in London . The recommendations and the behaviour of
the two pioneers were important steps on a journey whose destination
was not yet clear. Nevertheless, they were an important move in the
right direction. In later sections it will be possible to see how the des-
tination, and the vision for the professions, clariﬁed.
4. Period B: Pioneering radiation protection 1928–1960
Several key publications from this eventful period are reviewed,
including the 1928 international recommendations with their evolution
over the following decade . WWII then intervened and changed the
context of radiation protection. In the 1950′s the ﬁrst recommendations
characteristic of today’s ICRP began to emerge, particularly ICRP-1. An
example of early successes of radiation protection in diagnostic radi-
ology is presented.
4.1. The 1928 international recommendations for X-ray and radium
The eﬀects of radiation to be guarded against in the 1928
J. Malone Physica Medica 79 (2020) 47–64
recommendations were: (a) Injuries to the superﬁcial tissues; (b)
Derangements of internal organs and changes in the blood . They re-
ﬂected the emerging consensus from the years prior to the London and
The recommendations are a three and half page document (Fig. 2).
Despite their simplicity, they include a clear statement about the re-
sponsibility of employers and assert that:
The dangers of over-exposure to X-rays and radium can be avoided by
the provision of adequate protection and suitable working conditions. It is
the duty of those in charge ….. to ensure such conditions for their per-
These ﬁrst sentences in this short document place duties on the
employer that ICRP and the radiation protection community have
championed since. In this they were ahead of their time as many en-
terprises continued with little regard for the safety of personnel.
The protective measures advocated were simpler than those in
….. for whole-time X-ray and radium workers: (a) Not more than seven
working hours a day. (b) Not more than ﬁve working days a week. The
oﬀ-days to be spent ….. out of doors. (c) Not less than one month's
holiday a year. (d) Whole-time workers ….. should not be called upon
for other hospital service.
This reﬂects the reasonable self-interest of the professional group
from which it comes. Concerns in this vein persisted and were still re-
ﬂected in the special conditions of employment for radiation workers
right up to the 1970 s.
The requirements for staﬀ take a page, and include, among other
• X-ray departments should not be situated below ground-ﬂoor level.
• All rooms, including dark-rooms, should be provided with windows
aﬀording good natural lighting and ready facilities for admitting
sunshine and fresh air whenever possible.
• All rooms should preferably be decorated in light colours.
•In the case of X-ray treatment, the operator is best stationed com-
pletely outside the X-ray room behind a protective wall
• Screening examinations should be conducted as rapidly as possible
with minimum intensities and apertures.
In addition, generous room size, temperature, ventilation, location
of the generator, the X-Ray tube, the operator, arrangements for
Fig. 2. The ﬁrst page of the ﬁrst International Recommendations for X-Ray and Radium Protection, from the International Congress of Radiology, 1928 .
J. Malone Physica Medica 79 (2020) 47–64
screening (ﬂuoroscopy), some practical suggestions on technique, and
protective gloves are all speciﬁed. The lead equivalents advised for
shielding the tube and room in which it is used are inadequate by to-
day’s standards. An indication of the circumstances prevailing in
practice can be gleaned from the statement that:
if the protective value of the X-ray tube enclosure falls short of the values
given ….. the remaining walls, ﬂoor and ceiling may also be required to
provide supplementary protection for adjacent occupants to an extent
depending on the circumstances.
There is little mention of patient issues in the diagnostic sections,
other than the need to make adequate arrangements for protecting the
operator against scattered radiation from the patient. Personal and area
monitoring was taken care of ingeniously: It should not be possible for a
well rested eye of normal acuity to detect in the dark appreciable ﬂuores-
cence of a screen placed in the permanent position of the operator. Advice
on radium handling for treatments is provided in a separate section and
will not be addressed here, other than to note it proposes that: Discretion
should be exercised in transmitting radium salts by post.
A full section is devoted to electrical safety to avoid electrocution of
staﬀ, which must have been a real hazard. This is not deemed necessary
in today’s radiation protection manuals, but in the author’s department,
electrical safety checks were part of QA system up to a decade ago. This
was, among other things, to protect patients from the risk of micro-
shock, which could be a real hazard .
4.2. Evolution of recommendations and WW II
The 1928 recommendations laid the foundations for further work.
They were quickly followed by publications in 1931, 1934, and 1937
that made additions, dealt with omissions, and clariﬁed the original
[2,30,31]. The issues of time, distance and shielding were identiﬁed as
unambiguously important. The publications addressed real fears of
acute deterministic injury, and of genetic damage arising from gonad
radiation (rather than pregnancy protection).
The 1931 version added about half a page to the original. Much
good practical advice is included, for example: Palpation with the hand
should be reduced to the minimum. It also includes some frankly wrong
advice: An operator should place himself as remote as practicable from the
X-ray tube. In addition, the authors appear to be exasperated with the
practicalities of getting their recommendations implemented and noted:
One inevitably wonders in how many radiological clinics such continuous
control of the state of health has really been accomplished! Plus ça change,
plus c'est la même chose. The 1934 and 1937 versions continued to
draw on new developments, ideas, and knowledge.
Regarding dose limitation, the 1934 Congress set a quantitative
permissible dose level of 0.2 R/day (1 R/week). Prior to this, the per-
missible level, though expressed in various ways and not always re-
cognised, was up to 100 R/y (approximately equal to 1000 mSv/y) .
The U.S. Advisory Committee adopted a lower value, half of the 1934/7
level . The evolution of dose limits from the 30’s to the 90’s is further
dealt with in Sections 5.2.1 and 6.5 and Table 2.
Thereafter World War II intervened, and the 1940 congress planned
for Berlin was cancelled. An indirect consequence of this is that all the
records of the earlier congresses were destroyed during the war. The
area then became inactive until late 1945 . The creation and deto-
nation of nuclear weapons ushered in an age in which radiation pro-
tection became important for strategic reasons outside medicine and
scientiﬁc research. In addition, health physics became, out of necessity,
a science in its own right with signiﬁcant advances in survey instru-
ments, monitoring techniques, and radiobiological research, often
constrained under war-time secrecy . Experimentation with radio-
active materials led to potentially valuable uses in medicine. The use of
nuclear weapons profoundly inﬂuenced radiation protection, including
that in medicine, right up to the present time.
The legacy of the war eﬀort contributed both positively and nega-
tively to developments. On the positive side the epidemiological studies
of the bomb survivors provided deﬁnite information on the induction of
cancer and leukaemia in irradiated populations, and this shifted much
of the emphasis of radiation protection from its traditional focus on
deterministic eﬀects, to the probable incidence of cancers possibly even
at the low doses . However, on the negative side, the general po-
pulation fears arising from the Japanese bombings and continued nu-
clear testing, grew during the post war period until they became highly
politicised movements in the 1960s and later. A powerful video in-
stallation illustrating the testing programme is on display at the IAEA
headquarters in Vienna and can be seen at .
The impact of these was possibly underestimated by the radiation
protection community including that in medicine. Links between civil
nuclear activity, associated military enterprises, nuclear testing, and
environmental destruction were consolidated. The distrust of both
governments and science on nuclear and radiation issues is a legacy of
this period. Attempts to disentangle medical and socially acceptable
applications from the broader nuclear legacy have not generally been
successful, and the social sciences and humanities were generally and
unwisely excluded from attempts to do so (Sections 5.3 and 6.3).
The next recommendations from 1950 were published by the British
Journal of Radiology in 1951 . These were informed by much new
work and many insights that had arisen because of the war eﬀorts on
both sides of the Atlantic. However, their starting point was the work
accomplished between 1928 and 1937.
4.3. ICRP publications 1 recommendations
The 1950/1 publication recognised much of the new work on
bioeﬀects, reﬁnes the 1937 document and adds to it. Further re-
commendations were produced in 1954, 1956, and 1959 and often
published a year later [35–37]. The 1954/5 report is the ﬁrst one that
looks like a publication from ICRP and appeared as a supplement to the
British Journal of Radiology. The 1956/8 one continued with important
clariﬁcations on dose limits and references to pregnancy as opposed just
to gonad dose. The ﬁrst recommendations from ICRP in the numbered
series of its own publications, Publication 1, was at the end of the ﬁfties,
and initiated the long series that have come to enjoy a quasi-biblical
authority in radiation protection . This was an important step to-
wards the modern era and set the scene for the period until 1977 when
ICRP-26 was issued (Section 5.1).
It is important to note that ICRP continued to function within the
governance arrangement provided by the ICR. Thus, for example, ap-
pointment of commission members was made by the ICR International
Executive Committee based on nominations submitted by the com-
mission. This aspect of governance has not received adequate attention
and is diﬃcult to research due to the loss of records during WW II. The
new commission, over time, aﬃliated with many international orga-
nisations including UNSCEAR, WHO, IAEA, FAO, ILO and IRPA. Its
funding sources included the International Society for Radiology (ISR),
the Swedish government, and WHO. The work of the new commission
was entirely voluntary; no secretariat had yet been appointed .
The emphasis in the 1959 recommendations moved away from a
prescriptive list of practical advice toward a consistent framework re-
ferencing the related sciences. Most of its work was complete by 1956,
Summary of Evolution of Dose-Limits*
Period/Dates Headline Recommended Dose Limit(Whole body and annualised)
Pre 1928/1934 Up to 100 rems (1000 mSv)
1934/7 to 1950 60 rems (600 mSv)
At 1951 15 rems (150 mSv)
At 1959 5 rems (50 mSv)
At 1991 20 mSv (2 rems)
*See text and draws on Boice et al. 2020 .
J. Malone Physica Medica 79 (2020) 47–64
and it consolidated earlier ﬁndings. It dealt with basic concepts, ob-
jectives, critical organs, population exposure, genetic dose, medical
exposures, permissible doses including public doses, categories of ex-
posure, working conditions, controlled areas, monitoring, surveys, and
health surveillance. About half a page, of 22 in total, was devoted to
medical exposures. These were excluded from dose limits as a matter of
practical necessity. The main thrust of the medical concerns was its in-
creasing prevalence and gonad dose. The concept of the responsibility
of the person in charge or the owner retained its central place, and the
concept of qualiﬁed expert appears. Under many of these headings
ICRP-1 breaks new ground.
By the late 1950′s national publications began to appear, particu-
larly in the UK and the US, but also in many other countries. An early
example of the genre is the 1957 UK Code of Practice for the Protection
of Persons exposed to Ionizing Radiations is shown in Fig. 3 . This
was a notable and accessible advance for practitioners. It is about 40
pages with approximately 40 further pages of practical information,
including transmission curves for shielding, some of which would still
be helpful. It had some unusual features. First, it was issued from the
Prime Minister’s Oﬃce, perhaps emphasising its importance and pos-
sibly a security connection. But it is also possibly because no other
department felt they owned it. Second it was not a bound document like
a book or booklet. Rather it was a loose-leaf production well secured in
a cardboard folder with springs and string, possibly suggesting it had a
provisional character. The author’s second-hand copy was the ﬁrst
document widely available at the time he started working in medical
physics. It is divided into parts dealing with X-Rays and radionuclides.
The applications are clearly divided into diagnostic and radiotherapy.
Thus, it foreshadowed divisions that are still present today in the cer-
tiﬁcation of Medical Physics Experts (MPE).
4.4. An example from diagnostic radiology
Period B saw immense changes in diagnostic radiology. It would be
diﬃcult to overstate the importance of initiatives in education and
training that occurred during these years. Yet, from a radiation pro-
tection perspective, the single most important development was prob-
ably in shielding: i.e. safe/eﬀective tube housing, and beam collima-
tion. Most of the impetus likely came from occupational exposure
concerns, although patient protection also often beneﬁted. Medical
physics provided some impetus through testing and performance re-
commendations. Credit is due to equipment manufacturers for solutions
that are so eﬀective that tube housing seldom if ever fails today.
Another feature of this early period was the beginning of a more
thorough approach to diagnostic room shielding. Early recommenda-
tions were not always followed or adequate [25,38]. They were not
always related to the amount of work undertaken in the room and the
occupancy of adjacent areas. It was clear that shielding was required in
room walls, ﬂoor, and ceiling. In practice, walls were shielded more
often than ﬂoors and ceilings. Even when walls were shielded, doors,
windows and ducting areas were often omitted. The author has ex-
perience of such problems right up to the new millennium, and recalls
an occasion at the IAEA circa 2010, when the need for door shielding in
radiology departments was hotly disputed by a group of regulators and
a senior IAEA radiation protection expert. Once tube housing and room
shielding were dealt with, the aspects of radiation protection in diag-
nostic radiology that we now recognise began to receive more attention
4.5. Governance and ethics commentary
From the perspective of governance, the close connection of ICRP
with the International Congress of Radiology (ICR) continued
throughout this period. For example, it is speciﬁed that:
selection of the members shall be made by the ICRP from nominations
submitted to it by the National Delegations to the International Congress
of Radiology and by the ICRP itself. The selections shall be subject to
approval by the International Executive Committee (IEC) of the
Congress. Members of the ICRP shall be chosen on the basis of their
Fig. 3. Inside the front cover of the author’s second-hand copy of the UK Code of Practice 1957 .
J. Malone Physica Medica 79 (2020) 47–64
recognized activity in the ﬁelds of medical radiology, radiation protec-
tion, physics, health physics, biology, genetics, biochemistry and bio-
physics, with regard to an appropriate balance of expertise rather than to
nationality.) The membership of the ICRP shall be approved during each
International Congress .
The Commission could hardly be more exposed to a powerful interest
group professionally devoted to the use of radiation. This connection
lasted for 60 years and is an integral part of the heritage and culture of
ICRP. Exclusion of the social sciences and humanities from the expertise
range from which members might be chosen eﬀectively persisted.
These features are somewhat at variance with the image of in-
dependence the commission fostered, and inevitably inﬂuenced its
governance and the direction of its evolution. The commission pro-
jected itself as independent of governments, and in a literal sense this is
true. During this period, it also became deeply involved with interna-
tional organisations created and sustained by governments. Members of
the commission were generally highly positioned scientists or doctors,
often directly or indirectly employed by governments and actively in-
volved in society’s nuclear project. It is interesting to ask if the ICRP
governance arrangements were adequate to deliver stakeholder trust to
radiation protection communities including those in medicine. The
exclusion of those from outside these enterprises and from the social
sciences and humanities must, with hindsight, appear regrettable and
inevitably diluted the commission’s capacity to respond adequately to
the growing concerns about radiation in the post war period .
The recommendations of this period addressed real fear of acute
deterministic injury and genetic damage arising from gonad radiation.
These were conﬂated with advice on fresh air, shorter working hours,
longer holidays, bright ventilated rooms, and the risk of electrocution.
They aspire to establish safe, comfortable working arrangements and
this is what would be expected from a professional interest group. The
1928 recommendations mention patients once. In the ICRP-1 re-
commendations, only a half-page is devoted to medical exposures.
Attention to them continued to be slight, and unsatisfactory from a
governance point of view. However, it was an age of paternalism in
science and medicine, and hopefully that compensated for the lack of a
visible commitment to not harming patients.
Dose limitation was in transition during this period. The headline
whole-body annual values are the maximum that could be adopted
without direct risk of acute harm. This will be more fully discussed in
Sections 5.2.1 and 5.5 (see Table 2). It is reasonable to hypothesise that
the continuing exemption of medical exposures was probably due to the
close governance arrangement with ICR.
In aspiring to eliminate acute deterministic injury and avoid genetic
damage through avoidance of gonad radiation the recommendations
are in the spirit of their time, and strongly inﬂuenced by the value of
non-maleﬁcence or do no harm. The notion of justice may also have
contributed. The notion of the dignity and autonomy of the individual
may be present for workers and is implied in the duties imposed on the
owner or person in charge. However, it is missing for patients. Prudence
is likely to have been a signiﬁcant motivator of the whole project. There
is something of prudence and precautionary thinking in avoiding gonadal
radiation and the commitment to training and education. Honesty, ac-
countability, and solidarity, as conceived today, do not feature, except in
so far as they may have been manifested out of paternalism.
Finally, the equipment industry must be given credit, for its con-
tribution to protection in both the occupational and the medical areas
particularly in the development of good solutions to tube housing and
collimation. In this they demonstrated a governance framework capable
of responding to safety and standards issues.
5. Period C: Consolidation in medical RP (1960 – 1990)
The most signiﬁcant publication of recommendations during this
period was possibly ICRP-26, in 1977 . It supersedes all previous
recommendations of the commission, but not necessarily more tech-
nical committee reports [37,40,41]. The latter dealt with speciﬁc to-
pics, such as diagnostic radiology, nuclear medicine, technical problems
such as reference man, or the framework for the system including the
no threshold idea, optimisation, and ALARA in everything but name
[42–45]. The interim reports are generally more detailed scientiﬁcally,
but lack the status attached to more formal recommendations. This
pattern was repeated with numerous technical reports focused on spe-
ciﬁc issues paving the way for the 1990 recommendations issued at the
end of Period C . This period also saw the emergence of other in-
ternational players, particularly the European Commission (EC), The
International Electrotechnical Commission (IEC) and WHO.
The most important innovation during this period was the new re-
commendations from the commission . This was a major leap for-
ward. It eﬀectively created a rigorous coherent integrated framework
for the system of radiation protection. It is the deﬁning document for
the commission’s approach and its inﬂuence extends to the present
today. The governance arrangements for the commission continued
within the framework provided by the ICR. The document is longer
than earlier publications, about 55 pages. The version cited here carries
additional statements issued by the commission in 1978, 1980, 1983,
1984, and 1985 and extends to approximately 85 pages.
ICRP-26 is still familiar to many practitioners and hence will be
overviewed less than earlier recommendations. It identiﬁed the risks of
harm as somatic and hereditary. Somatic eﬀects were classiﬁed as
stochastic and non-stochastic, depending on whether the probability or
severity of the eﬀect is dose dependent. The former was assumed to
have a no threshold dose response relationship and included cancer
induction. Non-stochastic eﬀects had a threshold dose below which
they do not occur and included skin damage and cataracts. This is re-
cognisable today, over 40 years on, even if the understanding of the
phenomena is more nuanced.
The aim of radiation protection was stated as prevention of non-
stochastic eﬀects and limitation of the probability of stochastic eﬀects
to levels deemed to be acceptable. Notable attention was given to
identifying and “quantifying” the acceptable level and comparing it
with calculable radiation risk levels. Stochastic eﬀects were to be lim-
ited by keeping all justiﬁable exposures as low as is reasonably
achievable, economic, and social factors being considered and dose
limits being observed. This, in eﬀect gave the three principles of
Justiﬁcation, Optimisation (including ALARA) and Dose Limitation. ICRP-
26 provided a solid and apparently rigorous, coherent framework for
most of what has followed since.
The scope of ICRP-26 was expanded, compared with its pre-
decessors, as was its depth, internal consistency, and coherence. The
issues addressed include quantities, units, biological/epidemiological
dose responses, risks, and tissue weighting factors for risk for the ﬁrst
time. The dose equivalent limits were based on an acceptable level of
risk, and much less than those of the 1930′s, with a headline annual
value for whole body eﬀective dose of 50 mSv or 5 rem (Section 4.5 and
5.2.1, and Table 2). The notion of dose constraints was introduced, as
was classiﬁcation of workplaces, and appropriate levels of oversight for
diﬀerent areas. Area monitoring, individual monitoring, medical su-
pervision, and oversight of educational/ research activities, and occu-
pational exposure of pregnant women were all addressed.
A relatively short chapter (two and a half pages) on medical ex-
posures raised many of the areas to which full reports were later
dedicated. These include: exposures for diagnosis or treatment of ill-
nesses; systematic mass screening or periodic health checks; examina-
tions for medical surveillance; examinations for medico-legal or in-
surance purposes; and examinations or treatment forming part of a
medical research programme. Concerns about pregnant patients mer-
ited a paragraph. The value of the 10-day rule and good technique are
J. Malone Physica Medica 79 (2020) 47–64
mentioned without recommendations (see also Section 6.5). The need
for professional education and training get a perfunctory mention.
Notable omissions/ problems included protection of patients and the
impact of radiation on the environment. Protection of the patient, while
addressed, was a secondary consideration to occupational and public
This was particularly notable for justiﬁcation which was framed
only in term net beneﬁt without reference to patients’ wishes, reﬂecting
an almost moribund paternalism. The idea that net beneﬁt could be
quantiﬁed accurately initiated a ﬁction from which radiation protection
has yet to escape . Outcomes research is too inadequately devel-
oped to allow such calculations [46,47].
ICRP 26 was, perhaps, even more successful than might have been
expected. Its rigorous scientiﬁc style impressed and won the loyalty of
generations of radiation protection professionals who found it to be a
good ﬁt to their scientiﬁc culture. For scientists it was a framework to
be proud of and worked on the assumptions that appeared both scien-
tiﬁc and evidence based. It took almost two generations of successful
application before the unwarranted assumptions began to be ques-
tioned at the operational level.
In producing its 1990 recommendations the commission had three
aims: to take account of new biological information including trends for
safety standards; to improve the presentation of the recommendations;
and to maintain as much stability as was consistent with the new in-
formation . The length was increased to 77 pages supported by 120
pages of Annexes and references. The annexes relate to studies of bio-
logical eﬀects, epidemiology, units/measurement, and the basis for
judging the signiﬁcance of biological eﬀects.
One of the more surprising aspects of ICRP-60 is that the formal
governance arrangements had changed since ICRP 26 [39,46]. The new
arrangements are silent, although they are acknowledged in later
publications. In 1988, the commission moved from the protective wing
of ICR and was established as a registered charity in the UK, although it
retained its international character. There is no evidence that the
change in governance changed the approach and content of ICRP 60. It
continued with a rigorous quasi-scientiﬁc approach drawing on the
physical sciences, radiation biology and the growing body of post war
epidemiological evidence. There is little reference to the social sciences,
ethics, values, social or legal considerations.
The main chapters deal with: background to the commission’s work;
quantities and units; biological aspects of radiological protection;
system of radiological protection for various practices including occu-
pational and medical exposures; justiﬁcation, optimisation and dose
limitation; intervention in various situations; and implementation is-
sues including management and compliance.
It is not practical to discuss all the measures mentioned in the report
here but, because of their enduring impact, most are familiar to radi-
ological protection practitioners today. However, three topics are
brieﬂy addressed with a view to further commenting on them again in
Section 5.5 below. They are dose limits, the treatment of medical ex-
posures, and the treatment of diagnostic exposures of pregnant or po-
tentially pregnant women.
5.2.1. Dose limits and medical workers
Regarding dose limits, the main conclusions of ICRP-60 still prevail
today, almost thirty years later. Prior to that for almost 80 years there
was regular change (Table 2). Prior to the 1928/34 recommendations
there were no limits. The limits have been expressed in a variety of
ways, so that comparisons can be diﬃcult. In broad terms, however, the
headline annual whole body limit was reduced by a factor of about 4,
from 600 mSv to 150 mSv between 1934 and 1950, by a further factor
of 3 to 50 mSv by 1959, and an additional factor of 2.5 in 1990 when it
reached 20 mSv, and there it has remained [7,29,34,37,39]. The
average annual occupational eﬀective dose to medical workers trended
downward from ~ 70 mSv prior to 1939, to ~ 2 mSv in the late 1970 s
and below ~ 1 mSv today, except for those performing ﬂuoroscopically
guided interventions . Much of the decrease can probably be at-
tributed to the strong emphasis on optimisation, ALARA, and the
emergence of dose constraints.
The case for the 50 mSv value was most coherently stated in ICRP-
26 when the risk of apparently safe occupations was used as a bench-
mark. When ICRP 60 further reduced the headline value to 20 mSv, it
was partly based new biological ﬁndings and risk levels. Some felt that
the case for 20 mSv was not convincing and the limit should be further
reduced. Others felt that, even at 20 mSv, it was so low it would create
practical diﬃculties. In the event, the commission settled on 20 mSv,
but this somewhat damaged its image and led to questioning of the
validity of its scientiﬁc approach, which up to that point was relatively
5.2.2. Treatment of medical exposures in general
Regarding medical exposures, the commission’s approach is para-
doxical. Despite its close relationship with ICR, its attention to medical
exposures in the recommendations continued low, possibly to an extent
that medical issues began to be addressed by other agencies (Section
5.3). The section on medical exposures in ICRP 60 is only one page from
a 200-page document and lacks alertness to emerging problems in both
justiﬁcation and optimisation. The commission states: medical exposures
are clearly justiﬁed and because the procedures are usually for the direct
beneﬁt of the exposed individual . It was then, and still is the case that
a signiﬁcant proportion of radiological examinations are not justiﬁed in
practice [49–52]. The commission continues that because justiﬁcation
of medical exposure is good: less attention has been given to the optimi-
sation of protection in medical exposure than in most other applications of
radiation sources. ….. Doses from similar investigations cover ranges of as
much as two orders of magnitude. By the late 1980 s this problem was
clearly articulated, particularly in Europe and remains signiﬁcant even
The commission continued not applying a dose limit to medical
exposures.. It seems likely that it was not suﬃciently attuned to the
emerging problems noted above. It pointed out that it ….. has had
historical links with medical radiology and its advice in this area has often
been more detailed, presumably referring to ancillary committee reports
. However, committee reports though often technically excellent,
were of variable quality, and did not have the status or mandate of the
5.2.3. Pregnant or potentially pregnant patients
A concern in medical radiation protection is exposures of women
who are pregnant or potentially pregnant. Earlier recommendations
were focused on possible genetic damage to future generations and
addressed these in diagnostic exposures with collimation and gonad
shielding. The latter is an emerging current concern (Section 7). In
ICRP-60, possible damage to the embryo/foetus in pregnant women is
raised as it was in ICRP-26. However, in ICRP-60 the earlier advice that
the 10-day rule might be helpful is omitted and replaced by advice that:
the necessary information on possible pregnancy can, and should, be ob-
tained from the patient herself. This was an unreliable and insensitive
approach and leaves much to be desired. However, it further re-
commended that exposure of pregnant or potentially pregnant women
be avoided in the absence of strong clinical indications. In addition, it
commented that: exposure of the embryo in the ﬁrst three weeks following
conception is not likely to result in deterministic or stochastic eﬀects in the
liveborn child. (See Section 6.5 for further comment).
5.3. Other inﬂuential international publications
In 1984, the European Commission (EC) issued new Directive 84/
466/Euratom (a legally binding Directive to member states of the
J. Malone Physica Medica 79 (2020) 47–64
European Union). It laid down basic measures for the radiation pro-
tection of persons undergoing medical examination or treatment
(Fig. 4) . The EC already had directives in place for protection of
workers and the public. In addition, it had an extensive research pro-
gramme, and had embarked on publication of a series of related peri-
odic reports . In a global context, this was a unique initiative.
Singling out medical exposures for special attention was new and at-
tracted opposition from both regulators and from the radiology com-
munities in some member states. It is possible that the initiative arose,
at least in part, from the absence of ICRP recommendations that were
explicit enough to inﬂuence medical exposures, combined with a lack of
self-regulation in some national radiology communities. The Directive
is short but introduced ground-breaking requirements for training and
education for radiologists and allied staﬀ, equipment performance
standards and their assessment, quality assurance, patient dose mon-
itoring, as well as the requirement for an expert in radiophysics which
preceded the current requirement for a Medical Physics Expert.
The International Electrotechnical Commission (IEC) is head-
quartered in Geneva and has responsibility for global international
equipment standards. A total of 117 Technical Committees (TC) and
Subcommittees (SC) is responsible for developing standards for all types
of equipment. Electro medical equipment is dealt with under TC 62
which was established in the 1960s. It has four subcommittees and two,
SC 62B and SC 62C, deal with imaging and radiotherapy equipment
. These committees, often chaired by medical physicists, have a
signiﬁcant role in ensuring equipment safety and performance. In
Europe this is underwritten by the CE mark. In this period, the con-
tribution of national and regional standards organisations such as BSI,
DIN, CEN, CENELEC and the FDA held sway, but as trade became in-
ternational, the development of European and international standards
was gradually outsourced to IEC (see also Section 6.2.2). Standards are
important for radiation protection, although their impact is often un-
derestimated by medical physicists.
A 1975 WHO publication became a vade mecum for many medical
physicists. It was the Manual on Radiation Protection in Hospitals and
General Practice, Volume 3, X-Ray Diagnosis . It dealt compre-
hensively with protection of staﬀ and the public, purchase of equip-
ment, design and shielding of facilities, and management of equipment
through its life cycle. It also had an eleven-page appendix on medical
aspects of diagnostic x-ray protection which, incidentally, advised use
of the ten-day rule for women of reproductive capacity. The IAEA was
active in supporting radiation protection initiatives in the medical
context, although it focused largely on occupational issues until the
turn of the century. In addition, much readily applicable advice on
room shielding became available at both international and national
levels during this period [57,58].
5.4. The CT scanner
It may be surprising to learn that EMI (Electric and Music
Industries) which beneﬁted from the sales of the Beatles’ records in-
vested in the creation of the ﬁrst CT scanner. For a long time, these
imaging systems were known as EMI Scanners. The ﬁrst commercially
available CT scanner was the work of Godfrey Hounsﬁeld of EMI
Laboratories in 1972. The CT scanner mirrors Röntgen’s original dis-
covery in entering widespread application and receiving a Nobel Prize
within a decade . Röntgen received his in 1901 and the prize for CT
scanning was shared between Hounsﬁeld and physicist Alan McCor-
mack in 1979 . However, the high cost of the early generations of
CT scanner exercised some limitation on the speed of its dissemination.
The earliest CT scanners, even though limited to head studies, of-
fered new imaging capabilities that served patients well. During the
decades that followed, much innovation occurred culminating in the
multislice ultra low-dose performance of the current and new genera-
tion of scanners that can image the body from head to toe. The radia-
tion protection problems associated with CT systems were dealt with
largely through good equipment design by the industry and room/fa-
cility design that meant that staﬀ did not have to be in the room with
the scanner. The useful beam was usually fairly well conﬁned and
scattered radiation was not a great problem. Patient protection issues
were seldom discussed, and population doses were constrained by the
limited numbers of scanners deployed. However, all of this was to
change radically within a decade of the appearance of ICRP-60 (Section
5.5. Governance and ethics commentary
The governance issues already identiﬁed persisted into this period.
The relationship with ICR remained unchanged during and after the
preparation and publication of ICRP-26. However, by the time ICRP-60
was published this relationship had radically altered and the commis-
sion had been established as a registered charity. There is little evidence
of this change in the text of ICRP-60, and no evidence of a change in
direction or preoccupations. It is probable that the culture of the
commission was well established during the sixty years from 1928 to
registration of the charity.
The depth, internal consistency, and coherence of the treatment in
both ICRP-26 and ICRP-60 is impressive. The commission’s analysis of
the atomic bomb and revised dosimetry data probably gave rise to
much heart searching, but led to the conclusion that stochastic eﬀects
should provide the basis for dose limits. For the greater part this stands
the test of time. From an ethics point of view, the recommendations,
particularly in the downward revision of the headline annual whole-
body dose limit, impressively address issues of non-maleﬁcence and
justice. Likewise, they also address, though often not explicitly, the
demands of prudence. While some would doubt the honesty of the rea-
sons given for the 20 mSv decision in ICRP-60, it has stood the test of
time, and is still used throughout the world to this day. In addition, the
fact that the US did not adopted the 20 mSv value demonstrates the
pressure the commission was probably exposed to at the time.
The lack of engagement with medical issues in the recommenda-
tions continued, and they were relegated to committee publications of
varying quality. There was little evident appetite in the recommenda-
tions to address aspects of justiﬁcation, optimisation, systemically
variable patient doses, or management of potentially pregnant females.
In these areas, issues involving beneﬁcence/ non maleﬁcence were often
discussed, but reasonable expectations from other values including
dignity/ autonomy, justice and prudence were somewhat neglected.
Likewise, the absence of engagement with environmental issues and
with the social sciences and humanities remained a feature of the
commission’s stance. With the beneﬁt of hindsight, this is a serious
omission. After all Rachel Carson’s Silent Spring had already been pub-
lished to considerable acclaim .
The dignity and autonomy of patients, solidarity, and an explicit
consideration of prudence, were probably not on the commission’s
agenda during this period. While this might have been understandable
in the run up to ICRP-26, it was not so by the eighties when ICRP-60
was in train and the expectations of society and many individuals had
radically altered. This was clearly signalled in the initiative of the
European Commission with respect to medical exposures and the IEC
with respect to having safe equipment meeting transparent safety and
performance standards. The importance of honesty and communication
in the medical context received little attention in a world in which
consent was coming to the fore. Honesty was also systemically under-
mined by fostering the unchallenged illusion that harms and beneﬁts
could be routinely compared in a quantitative fashion [10,11].
The issues around radiology of pregnant or potentially pregnant
women have long been a source of dilemmas in radiology. The com-
mission’s contribution in the ICRP-160 recommendations did little to
resolve these and was somewhat at variance with a tentative initiative
in ICRP-26. At best, this is a failure of imagination in terms of the dignity
and autonomy of generations of women and an absence of honesty,
J. Malone Physica Medica 79 (2020) 47–64
prudence, and solidarity with them. This will be further discussed in
Sections 6 and 7.
Use of the Sievert (Sv) for two quantities, eﬀective dose, and
equivalent dose continued. Brieﬂy, the former is used to specify the
amount of radiation received by an organ with some adjustment for
diﬀerent radiation types. The latter sums together all the organ ex-
posures weighted for the risk attaching to each [62,63]. Clearly, they
are quite diﬀerent quantities, may vary greatly in numerical value, and
may be mentioned in the same sentence. Their continued use in this
way displays an arrogance about communication with those outside the
radiation physics community. It is oﬀensive to the dignity of members of
other professions and the wider community. It also undermines op-
portunities for honesty and transparency. This can’t be shrugged oﬀ; it
continues as one of many barriers to eﬀective communication.
6. Period D: The current situation (1990 to present)
In the period from 1990 to the present, the focus on medical ra-
diation protection has greatly increased . In the international
communities the impetus for this was initially most evident in in-
itiatives from the European Commission, supported directly or in-
directly by the IAEA, WHO, and IEC. ICRP continued to revise and
update its recommendations with two publications in 2007, one ICRP-
103, dealing with the system in general, and the other, ICRP-105, set-
ting out how it should be applied in medicine [62,63]. Almost a decade
later, toward the end of this period, ICRP broke with its traditional
pattern with respect to the social sciences and humanities, and issued a
publication explicitly addressing the ethics framework for the system of
radiological protection . The period also saw two new directives
from the EC further developing its commitment to medical exposures,
as well as initiatives from the IAEA, WHO, IEC, others. These are ad-
dressed in this section together with two examples illustrating how
some CT doses have become problematic.
6.1. ICRP-103 and ICRP-105
Both ICRP-103 and ICRP-105 reiterate the framework established in
ICRP-26 and reﬁned in ICRP-60 [62,63]. ICRP continues as a registered
charity and the methods of appointment to it and its committees re-
mained practically unchanged although they are reﬁned and stream-
lined. However, its essential culture, focus, and direction remained
unchanged, except for some engagement in consultation when pre-
paring documents for publication. It hoped that this move toward
transparency and involvement of some stakeholders would result in a
clearer understanding and wider acceptance of its recommendations.
During this period ICRP also successfully embarked on an ambitious
initiative to make all its publications available on an open access basis
. The success of this process made this paper possible.
As with the 1990 recommendations, ICRP-103 is a long document,
extending to 322 pages. The main recommendations are 135 pages and
the remaining 187 are taken up with references and two appendices,
one on units and quantities, and the other on biological and epide-
miological considerations. It draws on but does not supersede many
ICRP committee reports of varying quality, dealing with, for example,
medical issues, pregnancy, and CT dose management [64–66].
The 2007 recommendations update tissue weighting factors, and
information on harms based on new data published since ICRP-60.
While the position on deterministic eﬀects generally remains much the
same, the situation regarding eye doses evolved and required a revision
to the (eye) dose limit. The estimates of cancer risk attributable to ra-
diation exposure had not changed greatly since ICRP-60, while that for
heritable eﬀects was lower. The revised recommendations did not
propose fundamental changes, but they clariﬁed the system’s applica-
tion in a plethora of practical exposure situations. They maintained the
principles of justiﬁcation, optimisation, and the application of dose
With medical applications, there is a signiﬁcant development in the
2007 recommendations compared with ICRP 60. A full chapter (8
pages) is devoted to them and addresses justiﬁcation, optimisation,
special issues in radiotherapy, comforters, and carers; use of volunteers
in biomedical research, exposures during pregnancy, and use of the
quantity eﬀective dose in medicine. Brief comments on both the preg-
nancy issue and eﬀective dose are in order. Regarding the pregnancy
situation there is a notable improvement in the framing of the problem
and the recommended actions. For example, there is clear advice that
pregnancy status be determined prior to procedures, although it is silent
on how this might be achieved. In addition, there is an emphasis on a
pregnant patient’s right to know the magnitude, nature, and con-
sequences of in utero exposures. There is also information on prenatal
exposures. The recommendations state that most correctly performed
diagnostic procedures ——— present no measurably increased risk of pre-
natal or postnatal death, [or] developmental damage . Regarding
terminations, clear advice that they need not be considered at doses
below 100 mSv is oﬀered. All of this is a signiﬁcant improvement on
ICRP-103 is less than enthusiastic about the use of eﬀective dose to
quantify risk from medical exposures. It oﬀers reasonable considera-
tions in defence of this position. Principally, the age distributions of
workers (for which the eﬀective dose is derived) will usually be quite
diﬀerent from the age distribution of patients undergoing procedures.
The exposed organ distribution also diﬀers greatly from one type of
medical procedure to another. For these reasons, the commission re-
commends that the risks from medical diagnosis be evaluated using the
dose and calculated risk for individual organs and tissues. In practice
this advice is often ignored. The burden of undertaking the required
calculations is often beyond the resource and skill base of those un-
dertaking medical dose studies. It is a matter of concern that this has
been the best the commission can suggest in terms of quantities for
medical exposure, given its enormous commitment to quantities and
units for occupational exposures. However, thinking in the area has
developed and the commission is expected to issue a report identifying
conditions under which a form of eﬀective dose could be reasonably
applied in some medical studies. The medical chapter is followed by a
slightly churlish two-page chapter on the environment, although a fo-
cused report on the environment was later produced by a special
committee tasked with that purpose . It is diﬃcult to avoid the
conclusion that medicine, and the environment are straining the com-
ICRP-105, on medical exposures, is a report of the medical com-
mittee of ICRP (Committee 3). It is 64 pages long with the main content
extending over 52 pages. The annexe to ICRP 105 is 12 pages devoted to
previous ICRP committee reports on topics including pregnancy
[63,65]. ICRP 105 does not add much to ICRP-103 except for short
chapters/subchapters on justiﬁcation, DRLs and the unique aspects of
medical exposures. The section on justiﬁcation essentially endorses the
publication 103 view and parses and reﬁnes the concept a little. Like-
wise, there is some more discussion on DRL’s. The chapter on the un-
ique aspects of medical exposures is valuable and though less than three
pages, summarises the situation well. Apart from these, the value of
publication 105 lies in its brevity. It is essentially ICRP-103 with the
non-medical material stripped out. The medical reader will certainly
ﬁnd its 50 or so pages less forbidding than the 320 in 103. Interestingly,
while it provides speciﬁc guidance on ten areas in an Appendix, there is
no speciﬁc guidance on justiﬁcation, with the exception of an opaque
half page ostensibly directed at GP’s which is so general and patronising
that it is unlikely to have much impact on its target audience.
6.2. Other inﬂuential international publications
Around 1990, it became clear that the EC was taking a lead in
medical radiation regulatory and guidance initiatives. From the mid-
J. Malone Physica Medica 79 (2020) 47–64
nineties onward, a series of signiﬁcant initiatives came from the
European Commission, its radiation protection unit in Luxembourg, and
research consortia funded by the EC. By the turn of the century UN
organisations including the IAEA and WHO also assumed leadership
roles in aspects of the medical area. ICRP continued to produce good
work, including publications 103, 105 and 138 (Section 6.3), as well as
a stream of reports from its medical committee. But it had missed major
opportunities at the level of recommendations and advice to regulators,
and international bodies.
6.2.1. European radiation regulatory standards
In 1997 the European Commission replaced the 1984 medical ex-
posures directive with a new more comprehensive legal instrument on
health protection of individuals against the dangers of ionizing radia-
tion in relation to medical exposure . This highly developed reg-
ulation became national law in all member states of the European
Union and exercised considerable inﬂuence beyond it, both in the rest
of Europe and throughout the world. This regulation was later replaced
and enhanced in the new European Basic Safety Standards of 2013 .
The EC also produced publications, the RP series, in support of the
medical exposures Directive and continued to foster substantial related
research programmes . During the last decade, these initiatives
extended to exploring contributions of the social sciences and huma-
nities to radiation protection [71,72].
The topics of the RP publications are wide-ranging and served to
guide, regulators, practitioners, policy makers and member states on
practical implementation of sections of the Directives. They include:
medico legal exposures; interventional radiology; exposures during
pregnancy; early in utero exposures; dental radiology; population doses
from medical exposures; radiation induced circulatory disease; non-
medical imaging exposures; the medical physics expert; referral
guidelines; audit of radiological practice; and criteria for the accept-
ability of equipment, among many others. The net impact of the di-
rectives, their implementation in national legislation, and these support
publications was widespread informed debate within medical physics
on medical radiation protection which found its way into practice, some
of it without passing through ICRP. Successful policy actions on justi-
ﬁcation of medical exposures are an example [49–51,73].
6.2.2. International equipment standards
The IEC committee developing standards for medical imaging
equipment (SC 62B) was, during this period, a reserved but highly ef-
fective participant in an industry transitioning from national providers
to global players (Section 5.3). Traditionally, the approach in radiology
was to have a separate standard for each system component, e.g. se-
parate standards for X-Ray tubes, for image intensiﬁers, and so on. This
changed as newer whole system standards evolved. For example, there
are now system standards for mammography, CT, general x-ray –
ﬂuoroscopy, interventional systems, dental, Ultrasound and MR sys-
tems . For end users, these are more applicable. This has also had a
profound inﬂuence on aspects of equipment design, safety, and inter-
national marketability. Examples of component standards include those
for tubes/housing, generator accuracy/ reliability, CT dose speciﬁca-
tion and measurement protocols, interventional displays, and dose
display/management in radiology and ﬂuoroscopy.
National/regional standards bodies now tend to outsource much of
standards development to IEC. There is enthusiastic participation in
standards development from Asia, Latin America, and the southern
hemisphere, for example from Korea, China, Japan, Brazil and other
countries that did not participate 20 years ago. Participation from the
US is more episodic, though when it occurs, often through the FDA, it is
eﬀective. Finally, many of the EC criteria for acceptability of radi-
ological equipment published in RP 162 are taken from the appropriate
IEC standards .
6.2.3. IAEA, WHO, IRPA, National and Professional bodies
During this period, the IAEA reoriented its medical programmes to
include a signiﬁcant emphasis on radiation protection of patients
(RPoP) and established a dedicate unit and website for this purpose
[75,78]. The successes of this unit include signiﬁcant inﬂuence on the
development of the medical exposures section of the International Basic
Safety Standards; a joint conference with the European Commission on
Justiﬁcation of Medical Imaging; and the Bonn Conference and call to
action on medical exposures for the decade following 2012
[49–51,76–78]. In these initiatives it was partnered with WHO, which
had been a strong contributor to the area since its 1975 document .
In this period, it established the Global Initiative on Radiation Safety in
Health Care Settings with many contributions including the deﬁning
one on imaging asymptomatic persons which is discussed below
(Sections 6.4.2 and 6.5). Finally, the International Radiation Protection
Association (IRPA) took the lead with an initiative on developing a
good culture of radiation protection in the various settings in which it is
During this period, developments in multislice and more intensive
CT greatly improved its contribution to patient management. The net
result was a huge increase in patient numbers and in the dose per ex-
amination. The radiation output of machines greatly increased as did
the patient workload and the intensity of examination types. The net
result was a signiﬁcant increase in the shielding requirements for fa-
cilities, which was also driven in some regions by a reduction in the
regulatory dose constraints for facility design. This was often contested
at the time. The publications addressing and resolving this major pro-
blem for medical physicists all came from national or professional
6.3. Ethics sensibility, ICRP, and the medical context
Lauriston Taylor, a pioneer and father ﬁgure in both the US NCRP
and the ICRP declared that ‘Radiation protection is not only a matter for
science. It is a problem of philosophy, and morality, and the utmost wisdom’
. Taylor’s statement makes it clear that radiation protection, both
as a system and in practice, extends beyond the science that supports it
and leans on ethics, experience, common sense, and occasionally for the
privileged, wisdom. While ICRP’s formulations explicitly recognise and
emphasise the science, and many practitioners value common-sense,
the explicit place of ethics in the system had to wait until 2018 to be
formally recognised in report 138 . The initiative for the report
arose at a 2012 meeting in Fukushima City, and may be related to
diﬃculties implementing the system in practice at the time.
This report describes the set of ethical values that ICRP believes
informed the system of radiation protection since its inception. It is
based on a set of values to which all can subscribe and are commonly
used in medical ethics . It identiﬁes four core values: beneﬁcence/
non-maleﬁcence, prudence, justice, and dignity, as well as three pro-
cedural values that are required for the practical implementation, i.e.
accountability, transparency, and inclusiveness.
While these are essential to the system, it is not always clear how
they can be applied in speciﬁc areas. They cannot be directly mapped
onto justiﬁcation and optimisation. Medical applications are recognised
as needing an additional publication, in preparation by ICRP TG 109
[12,10]. In addition, there is a rich ethics tradition in medicine, in-
cluding the Hippocratic Oath. The most recent reiteration of the latter,
the Geneva Declaration, overlaps to a considerable extent with ICRP-
138 [15,10,85]. These considerations are crucial to the development of
radiation protection in medicine. Pending the report of ICRP TG 109,
considerable progress has been made in the published literature on
application of a ﬁve-value system to practice in diagnostic imaging. The
values are: Dignity/autonomy; Beneﬁcence/non-maleﬁcence; Pru-
dence/precaution; Justice; and Honesty (Section 2). Additional values
also under consideration, include solidarity and empathy [10,11,17].
J. Malone Physica Medica 79 (2020) 47–64
6.4. Examples of current dilemmas in imaging: Issues with CT scanning
The use of medical imaging technologies has greatly increased over
the past few decades. It has served medicine well in addressing the
needs of patients and opening new horizons to improved care.
However, it also brought with it, alarming sometimes poorly justiﬁed,
increases in population and individual doses, and requirement for much
greater shielding of CT facilities, all of which have been the subject of
much debate and anxiety [32,86–88]. These have been well discussed
elsewhere, as have the new ultra-low-dose CT systems and they won’t
be further addressed here. However, two less well rehearsed examples
of CT dose dilemmas are introduced and analysed in Sections 6.4.1,
6.4.2 and 6.5, and the shielding issue is brieﬂy addressed in Section
6.4.1. Problems or repeat CT scans
A 2019 IAEA meeting focusing on repeat CT scans and found cause
for concern in three prior publications. The cumulative eﬀective doses
were larger than expected. The dose from one scan is in the range
1–20 mSv. Yet repeat scans were accumulating doses in the
50–500 mSv range with greater than 1% receiving more than 100 mSv.
The patient proﬁles indicated that 10 to 20% were less than 50 years of
Multiple “repeat” radiological imaging is justiﬁable in many cir-
cumstances. However, repeat scans frequently do not need all the fea-
tures of the original diagnostic scan. A much more limited protocol may
provide the information required at “repeat” which is often predicated
on, for example, seeing if a mass is growing or shrinking. This requires
the clinicians directly involved, equipment suppliers, allied health
professionals and health authorities develop and implement suitable
strategies for nuancing justiﬁcation and protocols for repeat examina-
tions. Professional medical societies must develop, adapt, or improve
appropriateness criteria/ referral guidelines for patients who require
multiple and/or long-term follow-up imaging studies. When a series of
procedures can be reasonably foreseen, the justiﬁcation process should
consider the entire series not just the initial diagnostic event. The
reasons for this are both practical and grounded in the ethics of med-
icine and radiation protection (see Section 2 and 6.5).
6.4.2. CT-IHA (Individual health Assessment) in asymptomatic persons and
executive health checks
CT is increasingly applied to screen asymptomatic people for the
early detection of disease. A limited study indicates that this practice
occurs in most countries . Such screening practices arise in both
organized population-screening programmes and less structured set-
tings. Even with organized programmes, balancing beneﬁts and harms
is critical to ensuring positive outcomes. Less structured situations in-
cluding individual health assessment (IHA) can often challenge justiﬁ-
cation. ICRP recommended that social beneﬁt can be balanced against
the risk to individuals participating in medical radiological screening
activities. In some well organised screening programmes, beneﬁt/risk
studies indicate a net social gain and the programme is therefore jus-
tiﬁed. National mammography screening programmes working out of
an evidence-based framework often meet these requirements, although
the area is not without dispute. However, it is important to realise that
beneﬁts can be over emphasised, and harms under-played by en-
thusiastic advocates. This exacerbates the already troubled traditional
beneﬁt/risk considerations and leads to activities that challenge justi-
There is little evidence that CT-IHA is of beneﬁt in asymptomatic
individuals. The obvious harms include probable radiation harms,
mortality, morbidity, false-positives and negatives, incidental ﬁndings,
related stress, and direct/indirect costs. Incidental ﬁndings of un-
expected pathology can precipitate overdiagnosis, unnecessary worry,
and sometimes aggressive overtreatment with its attendant risks.
Incidental ﬁndings can also create unplanned expenditure that often
falls on the public health service, while the CT-IHA usually occurs in the
private sector .
Commercial services are widely available in many countries and
oﬀer CT-IHA scans to individuals for the early detection of lung, cardiac
and colorectal disease. An example is the executive screening pro-
grammes oﬀered at top-ranked cardiology hospitals in the United
States, which include a coronary artery CT scan to determine the cal-
cium score or visualize arteries. The packages include up to 12 cardi-
ovascular tests at a cost ranging from about 1000 to 25 000 US dollars.
The underlying assumption is that this aggressive and potentially
comprehensive screening prevents people from dying but there is no
evidence supporting this in imaging guidelines [93,94].
Formal standards and legal frameworks for addressing CT-IHA are
provided by the International and European communities respectively
[77,69]. Yet, even where authorities identify CT-IHA practices, they are
sometimes reticent about imposing regulation for various reasons .
In some countries, consumers may expect CT-IHA to be available and
have little awareness about the justiﬁcation issues raised by radiation
protection experts [96,97].
6.5. Governance and ethics commentary
During this period, ICRP continued as a registered charity. Within
this envelope, there was much change including a new secretariat
aligned with modern management priorities. However, the organisa-
tion’s culture, as manifest in concerns, membership and output re-
mained relatively unchanged, with a few exceptions. For example, to-
ward the end of the period, it produced ICRP-138 on the ethics basis for
the system of radiation protection . It became more outward
looking and a little more transparent in appointing members of the
commission. It also instituted consultation on draft documents prior to
publication and undertook a courageous initiative to make its pub-
lications available on an open access basis.
Following a decade during which medical exposures were receiving
much more attention from the EC, the IAEA, WHO, IEC, and IRPA and
the medical physics profession, its place in ICRP was, on the surface at
least improved. It was given a separate chapter, not just be an after-
thought, in ICRP-60. In addition, a report on medical exposures, ICRP-
105, was issued, which though a well-written summary of the com-
missions position did not address the emerging problems in the area.
Perhaps the area from which ICRP was most spectacularly absent (and
continues to be so) is in justiﬁcation of medical exposures. In this, the
IAEA, the EC and WHO led with numerous initiatives up to and in-
cluding the Bonn Call to Action .
The 20 mSv headline dose limit was retained, but the unease that
accompanied its introduction is not completely at rest. The reduction in
the occupational dose limit to eyes is a welcome response to developing
evidence. The continued use of the Sievert for two quantities remains an
obstacle to good communication and undermines honesty. As does the
absence of a single understandable quantity that can be used in dis-
cussion of harms and outcomes from patient doses.
How to handle irradiation of pregnant patients remains an un-
comfortable and inadequately addressed concern that undermines the
dignity and autonomy of at least some women, and might beneﬁt from a
greater presence of the social sciences and the humanities [98–100,65].
Advice continued to be given to the eﬀect that: exposure of the embryo in
the ﬁrst three weeks following conception is not likely to result in determi-
nistic or stochastic eﬀects in the liveborn child (ICRP-60, Section 5.2.3).
This approach to pregnancy, though widely adopted, is not uncontested
[100,101]. It is also remarkably insensitive to the fact that women who
have diﬃculty conceiving may regard loss of an embryo or foetus as a
signiﬁcant harm. Limiting recognition of damage to that evident in the
liveborn child is an inadequate approach to protection of early preg-
During the decade to 2020, ICRP excavated the implicit ethics basis
of the system of radiological protection . Almost twenty years
J. Malone Physica Medica 79 (2020) 47–64
earlier, signiﬁcant ethical questions were emerging in medical radiation
protection. Honesty and consent were coming to the fore and not only de
rigeur, but also legally binding in many jurisdictions. These and other
values, including dignity and autonomy, were addressed in European,
IAEA, RICOMET and the DIMOND projects among others [71,14,10].
This period also saw serious challenges from other disciplines including
the social sciences and the history of science. Documentary research
after the Chernobyl accident found a basis for criticism in the behaviour
of inﬂuential members of the commission who were also active in other
international organisations .
All of this conﬁrmed the importance of an ethics-based approach
like that outlined in Section 2, which will now be applied to the two CT
scanning examples in Section 6.4. The papers on repeat CT examina-
tions bring to light a perennial problem. The fundamental question
relates to how necessary repeats are, and if a “repeat” is required, must
it fully reproduce the original. We do not have a full answer to the ﬁrst
question, but they are probably not all necessary. The answer to the
second question is that repeats seldom need to reproduce the initial
diagnostic investigation, but often do. The harms involved in the un-
necessary components are real and reﬂect failures in:
• respecting the patient’s dignity and autonomy;
• doing unnecessary probable harm;
• justice through poor use of radiological resources;
• the absence of prudence in radiological thinking;
•honesty through possible inadequate communication with the pa-
tient and staﬀ; and
• solidarity with the wider community which may need the resources
These problems can be resolved through thoughtful multi-
disciplinary approaches to appropriate protocol development and
technical implementation. Doing so would enhance the ethical posi-
tions of the professions involved and save resources.
In the IHA example, there may be a governance problem in in-
stitutions providing it, and there are clear ethical problems in con-
ducting CT examinations with no beneﬁts and which do unnecessary
harms to healthy symptom free individuals. However there is a di-
lemma, and set against this, is a requirement to respect the dignity and
autonomy of an individual who may request or even insist on such a
procedure. This illustrates the situation that arises when values com-
pete with eachother and must be balanced. The dilemma may be mi-
tigated if honest comprehensible information about the beneﬁts and
harms is presented to the person requesting the scan. They may choose
to go ahead, or realizing it is a zero-gain situation and opt out of the
examination. Honest comprehensible information is critical to ethical
behaviour and patient consent. Without it, there are failures of the
other values including prudence, justice, and solidarity.
Regulators have been reticent about intervening in CT-IHA for
various reasons, including the importance of personal freedom and
empowerment, situations involving partially developed evidence bases,
subtle approaches in some countries requiring additional attention, as
well as uncertainty about the wisdom of intervention in medical prac-
tices [95,11]. This is an example where both ICRP and the radiation
regulators have not made an impact. WHO has stepped into this space
and developed a deep and broad framework of guidance for policy
makers who are anxious to deal with this diﬃcult problem .
7. Discussion and conclusions
Röntgen’s discovery and its application in medicine have been one of
the great success stories of science during the last 125 years. A sometimes
uncelebrated part of this success is the incisive and often timely con-
tributions of ICRP during most of the last century. They ensured that
Röntgen’s heritage is much safer and more eﬀective than it might other-
wise have been. It continued to beneﬁt millions of lives and wasn’t
abandoned or diminished out of fear of its destructive impact on the lives
of the early martyrs or later fears associated with nuclear projects. In the
coming decade, while celebrating ICRP’s centenary, we must also question
how it may best be continued. This review suggests some aspects of
governance, culture, and focus that might be considered when framing its
future contributions to medical radiation protection.
The commission has long declared, and to some extent overstated,
its independence. While it has strongly protected itself from some
conﬂicts of interest, its culture has been shaped by its initial depen-
dence on the executive council of the ICR. This lasted for ~ 60 years
and may account for some of its policies, including a hands-oﬀ ap-
proach to recommendations on medical applications. While it has been
attentive to medicine in numerous committee reports, these don’t ﬁnd
their way into its recommendations, and therein lies a weakness.
Systemic problems in justiﬁcation and optimisation are not addressed
with proportionate recommendations. Likewise, problems with identi-
fying appropriate objectives for shielding in diagnostic imaging, man-
agement of exposure of pregnant or potentially pregnant females and
other commonly encountered issues might have been more en-
ergetically tackled in the recommendations.
A signiﬁcant shortcoming in the approach to developing radiation
protection has been the absence of the social sciences and the huma-
nities. This issue is presently being played out in ethics, but there are
many other areas where interaction across these borders would pay rich
dividends. The values identiﬁed by ICRP, including dignity/ autonomy;
non-maleﬁcence/ beneﬁcence; justice; prudence/ precaution; and others,
especially solidarity, are shared with medical ethics and are regularly
discussed in the wider professional and academic literature. We must
learn to balance and be alert to them when embracing innovation. For
example, when considering AI, it is essential to adopt a prudent ap-
proach that doesn’t under-price risk .
Ethically sound medicine leans on more than scientiﬁc knowledge.
Uncertainty must be treated with respect and include the fact that we
do not know how to balance beneﬁt and risk as we seldom have a full
knowledge of both. It can be an illusion to think they can be compared
in a quantitative way. Outcomes research in medicine is often primitive
and not adequate to this task. The one exception is when there are
known or probable harms and zero beneﬁt. This corresponds with when
an examination is unjustiﬁed and such conclusions can safely be
reached. However, in more subtle situations the comparison is subject
to uncertainties, even in the deﬁnition of what should be included, and
this underlies much of the heat about screening programmes including
Today the pressure on science is greater than ever before, and it is
expected to deliver evidence in the service of politics, medicine, or the
market. In many circumstances, this does not, and possibly never will,
transfer smoothly . This dilemma applies to numerous areas in-
cluding nanotechnology, mobile phones, pharmaceuticals, genetically
modiﬁed organisms and use of radiation in medicine. Scientiﬁc hy-
potheses are released from the laboratory, without full evidential sup-
port, but with political or medical tasks to accomplish. The parallels
with Röntgen in 1895, ICRP over the decades since 1928, and Covid-19
today are obvious. All grapple(d) with incomplete uncertain knowledge
making a ﬁtful troubled journey toward safe medicine.
Of course, the judgments made here are provisional, and very much
post hoc. They are the author’s and based on the information available
at the time of writing. A diﬀerent person, or a person with new in-
formation or diﬀerent perspectives might reach diﬀerent conclusions.
Hopefully, they will encourage further exploration of the heritage of
ICRP as we approach the celebration of its centenary and get to know it
even better. One can speculate that Röntgen might be pleased with such
The author acknowledges the continuing encouragement and
J. Malone Physica Medica 79 (2020) 47–64
support of the chairman and trustees of the Robert Boyle Foundation.
Steve Ebdon-Jackson and Christina Skourou helped with invaluable
discussions. Lesley Malone read the entire manuscript and made useful
suggestions. The author is grateful to the ICRP commission and secre-
tariat for their vision in securing open access to the commission’s
publications dating back to 1928. Without this invaluable resource, this
paper would not have been possible. Hopefully, it does not give the
commission cause to regret the initiative! This research did not receive
any speciﬁc grant from funding agencies in the public, commercial, or
 ICRP. http://www.icrp.org/page.asp?id=3; 2020 [accessed 2 July 2020].
 BJR. Radiation Martyrs. Br J Radiol 2014; https://doi.org/10.1259/0007-1285-29-
341-273 [accessed 11 Aug 2020].
 Röntgen W. Ueber eine neue Art von Strahlen. Vorläuﬁge Mitteilung. In: Aus den
Sitzungsberichten der Würzburger Physik.-medic, Gesellschaft Würzburg; 1895, p.
 Röntgen W. Eine neue Art von Strahlen. 2. Mitteilung. In: Aus den
Sitzungsberichten der Würzburger Physik.-medic. Gesellschaft Würzburg; 1896, p.
 Röntgen W. Weitere Beobachtungen über die Eigenschaften der X-Strahlen.
In: Mathematische und Naturwissenschaftliche Mitteilungen aus den
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