Doctors' knowledge of radiation exposure: questionnaire study
BMJ 2003; 327 doi: https://doi.org/10.1136/bmj.327.7411.371 (Published 14 August 2003) Cite this as: BMJ 2003;327:371
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Sir,with the advances in ortho-surgery where the c-arm is
increasingly being used,the surgeon,assistant surgeons,OT
staff,anaesthetist,patient must have radiation measuring batches put on
them since safety measures like spacing c-arm utilising procedures in the
weeks OT list can be done besides the routine precautions.At the end of
the procedure the OT notes must also specify the amount of radiation
received by the patient.Besides doctors the patient must also be
councelled preoperatively about radiation.Doctors must have a fair
knowledge about radiation.I appreciate your article Sir.
Competing interests:
None declared
Competing interests: No competing interests
So whoever did not know that a lumbar spine Xray gave 120 times the
radiation of a chest Xray is a fool (A Downie BMJ letters 15/11). My
postman earns 200 times more than a graduate teacher I know in another
part of the world but that matters not a jot to anyone- it is the
absolutes that matter, ......
What exactly is the morbidity and mortality associated with having
Xrays done, compared, say, to prescribing a penicillin (another frequent
action of doctors, often considered unnecessary by some experts)? Tell us
that please instead of giving us numbers and units that are difficult to
decipher (fortunately we have been told about magnitudes in other
responses to this article describing background radiation, radiation
during flights etc.)
Having worked as a physician in the NHS (National Health Service) for
14 years I am struck by the way radiologist colleagues in Australia assist
in the management of patients- no one has asked me, "Will it change your
treatment?" yet!
Not knowing the difference between treatment and management, and that
patients are human beings with a mind, family and loved ones is ignorance
of a much greater magnitude.
I may be mistaken though- perhaps the ill-effects of radiation are
greater in the NHS!
Competing interests:
None declared
Competing interests: No competing interests
FURTHER EXPOSURES IN RADIATION AWARENESS
Dear Editor,
Shiralkar et al, in their recent article, highlighted the lack of
awareness amongst doctors of all grades of the degree of exposure to
ionizing radiation from common radiological examinations (1).
In their paper they stated that in March 2000 the UK Department of
Health issued new guidelines emphasising the importance and degree of
radiation. These are the Ionising Radiation (Medical Exposure) Regulations
(2). From the point of view of Emergency Department clinicians these
regulations essentially are legal requirements to ensure that the patient
has the correct radiological investigations performed, given the clinical
indication, and that there is no unnecessary exposure to radiation.
As these regulations have been in effect for over three years, we
compiled a six part telephone questionnaire in which we attempted to
ascertain the awareness of these regulations amongst Emergency Department
SHOs, in Northern Ireland, towards the end of their six month posting. We
personally attempted to contact ED SHOs in seven of Northern Ireland’s
acute hospitals. We managed to speak to forty SHOs in total and we
questioned them on awareness and understanding of the IR(ME) regulations
and if they had experienced any problems with the ordering of radiological
investigations since their introduction.
Of the forty SHOs only six were aware that the regulations were in
force and only one had encountered problems in ordering of X rays – this
was from a radiographer who refused to perform an X ray that she
considered was inappropriate. The other thirty four SHOs had never heard
of the regulations. Of all SHOs questioned twenty-one stated they had
received a general induction course on starting work in ED and nine
recalled part of the induction being dedicated to the radiology
department, but only one remembered the IR(ME) regulations being
mentioned!
If ED SHOs who, in the course of their daily work, order considerable
numbers of X ray examinations, are unaware of these regulations, we wonder
about the level of awareness amongst other members of the profession and
what should be done about it ?
Yours sincerely,
Dr Peter Shortt
Dr
Richard Wilson
Dr Declan Hughes
Dr Sinead Fitzpatrick
No competing interests.
(1) The Ionizing Radiation (Medical Exposure) Regulations 2000. www.doh.gov.uk/irmer
(2) Shiralkar et al. Doctors knowledge of radiation exposure:
questionnaire study. BMJ 2003;327:351-402.
Competing interests:
None declared
Competing interests: No competing interests
The following was posted to our support list in response to concerns
generated from the article. It may be of interest to your group because it
addresses patient perspectives -- in particular patients with indolent
cancers who have concerns about repeated use of CT for monitoring disease
and treatment response.
==
I've seen data showing higher incidence of secondary cancers in patients
with NHL - melanoma is but one.
So probably everyone can agree that something is contributing to the
increased risk. But what? It could be the NHL, the cytotoxic treatments,
treatment- disease- or genetic-based immune incompetence, and it could be
exposure to imaging radiation. How would any study tease out which
contributes most or least?
Maybe, it would be telling if we switched all lymphoma patients to
MRI monitoring. If the incidence decreases in twenty years we'd have a
fair estimate of how much CT contributes to the risk in this group.
I think Hodgkin's disease is where the best evidence of secondary
cancers is found because of the youngish age of the patients at diagnosis
and the excellent cure rate (~80%). But these patients are monitored
regularly by CT too. I find this practice particularly disturbing.
It's well established that radiation exposures increase risk of
getting cancer. If you have an alternative, such as MRI, which doesn't
increase the risk, it's prudent to use it. If you're young and have an
indolent cancer that requires frequent monitoring over many years, the
risks are greater.
I personally would not decline on participating in a trial because it
requires CT. But clinical trials do often increase the number of CT
exposures significantly, especially when the endpoint is time to
progression. Some studies require neck to pelvis CTs every 2 months. My
spouse has had ~20 such monitoring exposures. Something I now regret.
Karl Schwartz
President, Patients Against Lymphoma
www.lymphomation.org
Caregiver and Patient Advocate
Patient Consultant to the FDA/Oncologic Drug Advisory Committee
Participant in the NCI Progress Review Group for Blood Cancers
Competing interests:
None declared
Competing interests: No competing interests
We read with interest the study by Shiralkar et al [1] (BMJ
16.06.03). In the study, which involved a sample of doctors of varying
grades in two hospitals, 97% of doctors underestimated the dose of
radiation received by patients from some commonly requested radiological
investigations.
We conducted a similar survey at Derriford Hospital, Plymouth, a
large district General Hospital in South West England. We formulated a
simple questionnaire, in multiple-choice format, with a total of 11
questions. 240 doctors, of all grades, completed questionnaires, testing
knowledge of radiation exposure, terrestrial and medical. With a pass
mark of only 45% and a generous marking scheme, only 66 (27.5%) doctors
passed. Only 15.4 % to 25.8% of doctors knew the doses, relative to a
Chest X-Ray, of various, more complex, procedures involving ionizing
radiation. As noted by Shiralkar et al, some doctors thought that
Magnetic Resonance Angiography (28% of doctors) and ultrasound
examinations (10% of doctors) posed as much of a radiation risk as a Chest
X-Ray. Only 12.5% of doctors knew the risk of induction of fatal
carcinoma from CT of the abdomen (1 in 2000)[2]. Our results, of the whole
group of doctors, also showed that having attended a Radiation Protection
Course in the past correlated with performing better in the test.
What is probably of more concern, however, is that only 56.7% of the
30 Practitioners who, under IR(ME)R 2000 regulations [3], have
responsibility for justifying procedures, passed the test. Only 20% were
aware of the risk of fatal cancer from a CT of the abdomen. There was also
a significant difference in marks attained between Practitioners in their
first year of the Radiology SpR rotation (25% pass rate), compared with
SpR’s in later years, and Consultants (76.5% pass rate) confirming that
radiation protection teaching was effective at raising standards of
knowledge among Radiologists, although not perfect.
According to the IR(ME)R 2000 regulations, the responsibility of
justifying an exposure falls on the Practitioner, who makes the decision
independently. We believe that, in practice, the Referrer influences this
process by selectively presenting to the Practitioner, those clinical
details likely to justify the investigation that he or she believes is
appropriate. The decision to perform a test is therefore possibly taken at
an earlier stage than the regulations assume. This has benefits, in that
the Referrer often has a more complete knowledge of the clinical details.
Nevertheless, the process can be detrimental if the Referrer lacks
knowledge of the absolute, or relative, risks of an investigation. It is
not known if addressing this lack of knowledge would reduce radiation
exposure of the population. New methods of educating Practitioners,
Referrers and patients of the risks of radiation may benefit all these
groups.
REFERENCES
[1] S Shiralkar, A Rennie, M Snow, R B Galland, M H Lewis, and K
Gower-Thomas: Doctors' knowledge of radiation exposure: questionnaire
study
BMJ 2003; 327: 371-372
[2] National Radiological Protection Board. Protection of the Patient
in X-ray Computed Tomography. (ISBN 0 85951 345 8) London: HMSO, 1992.
[3] Department of Health: The Ionising Radiation (Medical Exposure)
Regulations 2000 , ISBN 0 11 099131 1 (http://www.doh.gov.uk/irmer.htm)
K Jacob, Specialist Registrar in Radiology
kjacob@doctors.org.uk
University Hospital of Wales, Heath Park, Cardiff CF14 4XW
G Vivian, Clinical Director of Radiology and Consultant Radiologist,
Department of Nuclear Medicine
J R Steel, Consultant Radiologist, Department of Radiology
Derriford Hospital, Plymouth PL6 8DH, UK
Competing interests:
None declared
Competing interests: No competing interests
EDITOR – We read with great interest the article by Shiralkar et
al.[1] However, concerns regarding extensive and often unnecessary
exposure of patients to radiation should extend to health professionals as
well. The majority of professionals involved in everyday radiographically
-assisted orthopaedic surgery may be unaware of the following simple
facts:
1. lead gowns should be 0.35mm thick
2. surgeons’ exposure is reduced by the inverted C-arm (image intensifier)
technique [2]
3. any distance <_90 cm="cm" from="from" the="the" image="image" intensifier="intensifier" is="is" thought="thought" to="to" be="be" unsafe="unsafe" _3="_3" br="br"/>4. the thyroid gland should be protected at all times and thyroid shields
shouldn’t be optional [4]
5. hands are at high risk from radiation and orthopaedic surgeons
controlling the image intensifier can reduce hand exposure [5].
In addition to the Ionising Radiation (Medical Exposure) Regulations
2000, it is desirable that all orthopaedic theatre staff have the option
of monitoring for radiation exposure with central (under lead gowns) and
peripheral monitors (finger or ear rings), whereas lead gowns should be
regularly monitored for cracks and thickness, and the imaging intensifier
monitored for radiation scattering. The areas most exposed to radiation
during orthopaedic surgery are the head and neck and the upper limbs. A
study of all radiation-related malignancies of these anatomical areas
would, therefore, be of great interest to the British Orthopaedic
Association.
1. Shiralkar S, Rennie A, Snow M, Galland RB, Lewis MH, Gower-Thomas
K. Doctors’ knowledge of radiation exposure: questionnaire study. BMJ
2003;327:371-2.
2. Tremains MR, Georgiadis GM, Dennis MJ. Radiation exposure with use of
the inverted-c-arm technique in upper-extremity surgery. J Bone Joint Surg
Am. 2001;83-A(5):674-8.
3. Mehlman CT, DiPasquale TG. Radiation exposure to the orthopaedic
surgical team during fluoroscopy: "how far away is far enough?". J Orthop
Trauma. 1997;11(6):392-8.
4. Tse V, Lising J, Khadra M, Chiam Q, Nugent R, Yeaman L, Mulcahy M.
Radiation exposure during fluoroscopy: should we be protecting our
thyroids? Aust N Z J Surg. 1999 Dec;69(12):847-8.
5. Noordeen MH, Shergill N, Twyman RS, Cobb JP, Briggs T. Hazard of
ionizing radiation to trauma surgeons: reducing the risk. Injury.
1993;24(8):562-4.
Competing interests:
None declared
Competing interests: No competing interests
Editor,
When whole body scans are discussed in BMJ, your authors refer to
"serious risk", but offer no dose figures for screening scans[1,2].
Shiralkar et al [3] brought into focus doctors’ lack of knowledge about
radiation doses in hospital, based on a 0.02 millisieverts [mSv] dose from
a common chest x-ray[CXR].
The smart responses to Shiralkar et al [4], showed willingness to
accommodate context by giving doses in everyday chest X-ray equivalents,
by supporting dose accounting, and by mentioning non-ionizing alternatives
such as MRI - see Grove[4]. But most of the responses show readers that
doctors don’t generally know enough about radiation doses, to be able to
keep track of a patient’s present or cumulative doses.
Those responses[4] which question methods used in Shiralkar et al,
tend to demonstrate the essential point – i.e. doctors don’t know. Some
responses, demonstrate awareness of not knowing together with a
conflicting indifference.
Neither do doctors know enough to keep track of their own radiation
doses, from such things as fluoroscopy – as per the responses [4]. Famous
medical man William Osler Abbott, managed to die in his early fifties from
fluoroscopy induced leukemia after experimenting with intestinal tubes[5].
Along the way, he helped create a culture of casual use of large amounts
of quicksilver(mercury) used in weighting the tubes – these tubes are
doubtless still in use in backwater hospitals.
Based on my one quarter century of continuous part-time hospital work
in Australasian hospitals, a lot of head and abdominal CT scans are done
for no finding, together with avoidable cancellations and repetition scans
due to inadequate preparation and poor organization(in OZ called “stuff
ups”). Patient self-removal of naso-gastric feeding tubes, is of circus
proportions. This results in confirming abdominal X-rays with each
reinsertion. Tyro nurses love a chance to practice insertions, and tyro
doctors, X-ray reading.
Painful memories of a doctor upgrading to keyhole technique, whose
surgical outcomes generated enough radiology to convert me to preventative
CT population screening. The unhappy sequence was - failed keyhole
gallbladder removal – - open gallbladder removal – internal leak -
collection - CT scan – intravenous food, drain, quintuple antibiotics.
Three months later – free fluids(free fluids has nothing to do with
publicly funded NHS).
Based on observation and personal communications with people in the
community, doctors often fail to hunch diagnose in symptomatic patients,
and so order non-yielding inappropriate radiological investigations – this
increases the patient’s feeling of despair, since the patient knows
something is wrong, yet remains loyal to a doctor who may well himself be
depressed. Death is sometimes the patient outcome.
One interesting, yet herring-like response to Shiralkar et al - see
Bury[4], and one reference given - see Sharma[4], introduced the idea of
hormesis - via JR Cameron’s relaxed approach to radiation doses. Simply
put, hormesis holds that doses of up to 200 mSv/year may be good for you -
see Bury[4], and doses of 100 mSv per year are not worth measuring - see
ref via Sharma[4]. Please note 100 mSv equals 5000 chest X-rays!
Despite the above, when whole body scans are discussed in BMJ [1,2],
your authors offer no general dose figure for screening scans.
My enquiry to one Sydney firm offering targeted CT scanning(not whole
body scanning)[6] and the brochure supplied[7] informed me of the
following dose equivalents(reformatted here)*:-
1.Background radiation in 7 days = 0.04 mSv [2 mSv/year]
2.Domestic pilot(annual) = 2.0 mSv [50 CXRs]
3.Chest X-ray = 0.04 mSv
4.Return flight Australia to UK = 0.15mSv [3.75 CXRs]
5.Screening Scan(heart or lung) = 0.12 [3 CXRs]
6.Coronary angiogram = 3.1 mSv [77.5 CXRs]
7.Barium enema = 7.2 mSv [180 CXRs]
(*Brochure states “depending on body size”) (A sievert is the modern
term for what used to be called a “rem”. 1 mSv = 0.1 rem[8]). Additional
in depth information supplied by manufacturers about radiation dose for
Toshiba scanners is journal published(see Westerman 2002[9]).
A second Sydney firm I contacted[10], do offer Whole Body Scanning,
but as reported by Zinn[11], now require a doctor referral. They sent me
radiation dose figures as follows:-
1.Background radiation = 5 mGy [milliGrays]
2.Virtual colonoscopy = 5-10 mGy
3.Full Body Scan = 10-20 mGy
4.Barium enema = 10 mGy
5.Angiogram = 20-50 mGy
(A Gray or Gy, is the modern term for what used to be called a “rad” –
Radiation Absorbed Dose. 1mGy = 0.1 rad.[8])
Given the first Sydney firm’s higher dose estimate for a standard CXR
- 0.4 mSv versus 0.2 mSv of Shiralkar et al, and different units used by
the second firm, none of the above doses look in the least frightening, in
light of the lack of dose accounting or dose knowledge[3]on the part of
hospital doctors.
When taken in context of JR Cameron’s 200 mSv per year being “good
for you”, a $900(AUD) body scan seems to rob the customer of deserved
access to a needed dose of part of the electromagnetic spectrum. The money
might be far better spent taking holidays in a spa in Ramsar, Iran. There,
naturally occurring high level radiation creates feelings of “radiation
envy” in Floridian experts[12]. It seems possible that doctors will be
coming up with terms like “radiation addiction” before long.
A society smart enough to make a CT Scanner, should be smart enough
to automatically and digitally document radiation tally doses, and share
these with patients.
Phil Colquitt
[1] Smith R. The screening industry. BMJ 2003; 326(26 April 2003).
[2] Swensen SJ. Screening for cancer with computed tomography. BMJ
2003 326: 894-895.
[3] Shiralkar S, Rennie A, Snow M, Galland R B, Lewis M H, Gower-
Thomas K. Doctors' knowledge of radiation exposure: questionnaire study.
BMJ, Aug 2003; 327: 371 – 372
[4] Responses to Shiralkar et al.
http://bmj.com/cgi/content/full/327/7411/371#responses
[5] Schnabel TG Jr. William Osler Abbott: his double lumen tube.
Trans Am Clin Climatol Assoc. 2001;112:50-60.
[6] Personal communication – email - Sydney Heart and Body Scanning.
Sydney. NSW. Scanner stated as Toshiba Aquillon ultra fast low dose CT
scanner.
[7] Sydney Heart and Body Scanning. CT Health Scan News. Website at
http://www.heartandbodyscanning.com.au
[8] United States Food and Drug Administration. Radiation Quantities
and Units. Available at:- http://www.fda.gov/cdrh/ct/rqu.html on 23 August
2003.
[9] Westerman BR. Radiation dose from Toshiba CT scanners. Pediatr
Radiol. 2002
Oct;32(10):735-7; discussion 751-4. Epub 2002 Aug 27.
[10] Personal communication - Bodyscan Australia. Sydney. NSW.
Website at www.bodyscan.com.au Scanner stated on brochure as Philips
MX8000(32 slice per second).
[11] Zinn C. New South Wales cracks down on commercial scanning BMJ
2003;326:1350 (21 June).
[12] Ghiassi-nejad M, Mortazavi SM, Cameron JR, Niroomand-rad A,
Karam PA. Very high background radiation areas of Ramsar, Iran:
preliminary biological studies. Health Phys. 2002 Jan;82(1):87-93.
Competing interests:
I delude myself that I have shares in, and am CEO of, my own well-being
Competing interests: No competing interests
It is a good reminder to us all to consider what are the doses of
radiation used in treatment or investigation. However, there are several
under-stated factors in the article and discussions:
1. Does it matter? Several correspondents state that the unit-of-measure
CXR is so low-dose, that it becomes irrelevant that something else is 400
times that dose. If we are to balance 100 - 250 deaths per 55 million
population, related to over-radiation, against who knows how much death
and disability if we under-irradiated, or stopped irradiating ...
2. My local colleagues doubt the stated irradiation doses. Over the odd
lap cholecystectomy this week, I have enquired of the radiographer who
dials up the doses, how many CXR equivalents does the cholangiogram
deliver? Shiralkar says 65, my colleagues say 2 - 3. I would like
Shiralkar et al to clarify where they get their comparitive doses figures,
and how well they reflect the practices of most XRay departments.
3. Others in this discussion have raised important questions also. Whilst
in all investigations and treatments we should know what the 'therapeutic
index' is (benefit/harm ratio), I am not sure that Shiralkar et al (or the
BMJ reviewers who chose to publish) have contributed to our understanding
of that concept.
Competing interests:
None declared
Competing interests: No competing interests
I read your article with interest. As an Orthopaedic trainee, your
article heightened my curiosity regarding my own radiation exposure during
fluoroscopic- assisted surgery. We are required to wear a 3mm thick lead
coat, but thyroid guards are scarce and I wonder how much irradiation I
absorb when nailing a femur. I also wonder if my future children will be
healthy...
Competing interests:
None declared
Competing interests: No competing interests
Lead Aprons: Historical & Scientific Basis for Change*
The U.S. Radiologic Technologist Health Study 1983-1998, which
included 90,305 radiographers (of whom 77% were female), revealed
increased incidence of breast cancer among female radiographers.
Interestingly, standard lead aprons, which have not changed appreciably in
almost a century, offer no protection to the lateral aspect of the breast
or axillary region, particularly in large-breasted persons. The leaded
rubber does not drape well over breast, the arm holes or arm openings on
the apron thus being projected foreward, thereby increasing exposure of
this radiosensitive area. I contend that to some degree, perhaps more
founded in historical retrospect than in mathematics, the "apron" design
itself contributes fundamentally to breast cancer incidence among female
radiographers. Of the three cardinal principles of radiation safety
(time, distance, and shielding), perhaps shielding is the most amenable to
affect safety outcomes.
In the US, it took 50 years to outlaw x-ray hair removal machines.
The practice ended in 1946. Shoe-sizing x-ray machines were pulled from
stores in the early 1950's after 40 years of use. With lead protective
aprons its been about 80 years now. Considering the increased incidence
of breast cancer in female radiographers, perhaps its time for a little
innovation in lead "aprons" relative to the upper female anatomy.
The self-descriptive term "apron" equates to the open-sleeve, or
sleeveless pattern, characteristic of garments intended to protect the
torso. While materials, fasteners, velcro, and colorful print styles have
evolved, the basic lead apron design has remained frozen in time for the
better part of a century! During the early 1900's with the determinations
by Bergonie & Tribondeau (1906), and Ancel & Vitemberger (1925),
the biological aspects of radiation-induced injuries were apparent.
Cancerous limbs, amputations and other horror stories prompted best-
practice modifications increasing the use (or at least the availability)
of protective aprons by the year 1925. Progressive technical improvements
in x-ray tubes (now shielded!), collimation cones, and techniques in
general, resulted in a generalised 'relaxation' of safety concerns
regarding medical x-rays which persists to this day. Once dangerous
machines are now safe,....so how can they be dangerous? Today, like
children fighting on a shoolyard, great academics and great scientists
argue between radiogenic cancer and hormesis. If you could ask Madame
Curie or Clarence Dally or Elizabeth Fleischmann today, had they known the
"potential" risks, would they have used the best available protection,
what do you think their reply would be? Regarding human life, espically
one's own, rational individuals usually err on the side of caution.
Competing interests:
None declared
Competing interests: No competing interests