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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 28, No 3, May/June 2017
AFRICA
139
Editorial
Radiation safety: time to act
SC Brown
It is an acknowledged fact that interventional cardiologists
have the highest occupational radiation exposure of all medical
professionals. As a matter of fact, interventional cardiac
procedures represent the largest contribution of ionising radiation
source after computerised tomography and nuclear medicine.
Modern therapies and the need for quality radiological imaging
have dramatically increased the use of ionising radiological
imaging in cardiology.
Radiation safety is rapidly becoming an important issue. The
first major drive towards this goal gave rise to the establishment
of the international radiation protection association (IRPA) in
late 2002, leading to the publication of guiding principles for
establishing a radiation-protection culture.
1
The aim of such a
culture is to substantially reduce radiation dose to both patients
and staff.
Biological effects of radiation
It should be taken into account that patients, technicians,
nurses and cardiologists are at risk of these effects. There are
two categories of unwanted effects when exposed to ionising
radiation:
•
Deterministic effects: here an identifiable threshold level exists
and the severity of effect intensifies with increasing dosage of
exposure. Biological effects occur as a result of cell damage
and death. Symptoms are related to the extent of cell death.
Dermatological effects and cataracts are typical examples of
deterministic effects.
•
Stochastic effects: these follow a linear non-threshold theory,
which essentially means these effects occur by chance. There is
no minimum exposure, and risk increases linearly with radia-
tion dose received. Cancer in an exposed individual occurs
due to the mutation of cells as a result of chromosomal
translocations.
Health hazards
•
Cataracts: posterior sub-capsular cataracts have been report-
ed in 50% of cardiologists and 41% of nurses working
in interventional catheterisation laboratories.
2
The authors
observed that lens changes were associated with several years
of work without eye protection and cumulative doses were in
the range of 0.1 to 18.9 Sv.
•
Brain tumours: several case reports of brain tumours have
emerged in the literature and have occurred in more than 31
physicians working in catheterisation laboratories, mostly
interventional cardiologists.
3-5
Of particular interest is the fact
that up to 85% of brain tumours were left sided – the area
of the head closest to the X-ray tubes. The physicians in this
report were exposed to ionising radiation over a period of 12
to 30 years.
•
Other: thyroid changes and neoplasms, hypertension, hyper-
lipidaemia, reproductive and even psychological effects have
been described.
6-8
Hair loss and skin damage may follow
prolonged exposure during fluoroscopic procedures. These
vary from temporary erythema to necrosis of the skin and
subcutaneous tissues. A single dose of 6–8 Gy on a 5-cm
2
field
may trigger tissue damage.
9
It should be noted that the hands
of operators receive the highest exposure during cardiac
interventions.
Food for thought
The article by Rose
et al
. (page 196) in this edition of the
journal gives a sobering perspective on radiation protection in
South Africa.
10
The study included public- and private-sector
radiologists and cardiologists. It is obvious from the results that
a complacency and lack of knowledge regarding radiation safety
is prevalent among cardiologists.
In essence, the results show that little or no formal education
for cardiology fellows regarding radiation protection is offered
during training. Even more disconcerting is the fact that even
though heads of units (both adult and paediatric cardiology)
acknowledged the need for radiation safety measures and
training, precious little appears to be done to address the
issue. This is compounded by the fact that junior fellows
expressed concerns regarding the effects of radiation exposure
on their long-term health, and that only one question regarding
radiation safety appeared in the national exit examinations for
cardiologists.
What should be done?
It is mandatory to establish a radiation safety culture for
cardiologists. Basic training should be available for all healthcare
workers in the catheterisation laboratory, and ongoing radiation
safety courses should be obligatory. Unless training units actively
promote and examine fellows on radiation safety, little will change.
Simple precautions to minimise exposure to patients, staff
and operators should be instituted as enshrined in the ALARA
(as low as reasonably achievable) principles. The American
Heart Association statement on enhancing radiation safety in
cardiovascular imaging may be followed as a guideline – clear
Department of Paediatric Cardiology, University of the Free
State, Bloemfontein, South Africa
SC Brown, MMed, FCPaed, DCH,
gnpdscb@ufs.ac.za