PMP
Progress in Medical Physics 30(4), December 2019
https://doi.org/10.14316/pmp.2019.30.4.75
eISSN 2508-4453
Review Article
Review of National Diagnostic Reference Levels for
Interventional Procedures
Min Young Lee , Jae Kwon , Gang Woo Ryu , Ki Hoon Kim , Hyung Woo Nam , Kwang Pyo Kim
Department of Nuclear Engineering, Kyung Hee University, Yongin, Korea
Received 6 December 2019
Revised 19 December 2019
Accepted 23 December 2019
Corresponding author
Kwang Pyo Kim
(kpkim@khu.ac.kr)
Tel: 82-31-201-2560
Fax: 82-31-202-8106
Diagnostic reference level (DRL) is employed to optimize the radiation doses of patients. The
objective of this study is to review the DRLs for interventional procedures in Korea and abroad.
Literature review was performed to investigate radiation dose index and measurement
methodology commonly used in DRL determination. Dose area product (DAP) and fluoroscopy time
within each major procedure category were systematically abstracted and analyzed. A wide
variation was found in the radiation dose. The DAP values and fluoroscopy times ranged
0.01一3,081 Gyㆍcm2 and 2一16,878 seconds for all the interventional procedures, 8.5一1,679
Gyㆍcm2 and 32一5,775 seconds for the transcatheter arterial chemoembolization (TACE), and
0.1一686 Gyㆍcm2 and 16一6,636 seconds for the transfemoral cerebral angiography (TFCA),
respectively. The DRL values of the DAP and fluoroscopy time were 238 Gyㆍcm2 and 1,224
seconds for the TACE and 189 Gyㆍcm2 and 686 seconds for the TFCA, respectively. Generally, the
DRLs of Korea were lower than those of other developed countries, except for the percutaneous
transluminal angioplasty with stent in arteries of the lower extremity (LE PTA and stent), aneurysm
coil embolization, and Hickman insertion procedures. The wide variation in the radiation doses of
the different procedures suggests that more attention must be paid to reduce unnecessary
radiation exposure from medical imaging. Furthermore, periodic nationwide survey of medical
radiation exposures is necessary to optimize the patient dose for radiation protection, which will
ultimately contribute to patient dose reduction and radiological safety.
Keywords: Interventional radiology, Radiation protection, Diagnostic reference level, Patient dose,
Radiation exposure
Introduction
the use of interventional radiology is rapidly increasing
with the increase in average life expectancy and techno-
Interventional radiology is a medical specialization that
logical development.1)
involves performing a range of imaging procedures to
Fig. 1 shows the number of interventional radiology pro-
obtain images of the inside of the body of a patient. Inter-
cedures performed during the period of 2007–2011, as re-
ventional radiologists conduct various procedures, such as
ported in a 2013 domestic study. The use of interventional
treating tumors, taking organ biopsies, or placing stents, by
radiology increased by approximately 12% per year, from
inserting miniature instruments and thin catheters into the
22,000 in 2007 to approximately 35,000 in 2011. These re-
body via an artery or a vein. Interventional radiology has
sults included only the procedures involving imaging tests
the advantage of reducing medical expenses as well as the
performed during interventional radiology in that period.
pain from invasive procedures (e.g., surgery). Currently,
Therefore, the actual number of procedures is expected to
Copyright © 2019 Korean Society of Medical Physics
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Min Young Lee, et al：DRL of Interventional Procedures
76
Therefore, the necessity of setting a reference radiation
40,000
Number of examinations
dose for a patient has emerged. As interventional radiology
is a procedure that is directly related to the life of the pa-
30,000
tient, it is inappropriate to apply extremely strict controls.
Therefore, the equipment or institutions that administer
20,000
extremely high or extremely low radiation doses need to be
identified, and the doses should be optimized.
10,000
A reference level was introduced to implement radiation
dose reduction and establish a reference standard. This
0
2007
2008
2009
2010
2011
concept was first introduced in ICRP Publication 60.3) Subsequently, the ICRP recommended the use of diagnostic
Years
Fig. 1. Number of interventional procedures per year in Korea.
reference levels (DRLs) for medical purposes in ICRP Publication 73, 8 and ICRP Supporting Guidance 2.4,7)
be larger than the above value.2) In addition, interventional
The International Atomic Energy Agency (IAEA) also
radiology requires a longer time and relatively higher radi-
endorses establishing DRLs, the recommended radiation
ation doses than other diagnostic radiology examinations.
dose levels for patients in accordance with the medical
Considering its increased usage and high radiation dose,
conditions, in each country.8) According to these guide-
currently, radiation protection and patient dose manage-
lines, various countries, such as the United Kingdom, the
ment are important in interventional radiology. Further,
United States, and European countries, are conducting
because interventional radiology is an important proce-
radiation exposure status surveys and DRL studies on vari-
dure directly related to the survival of a patient, it is inap-
ous diagnostic procedures, to optimize patient dose man-
propriate to apply extremely strict measures on the radia-
agement.
tion exposure received by the patient. However, efforts to
In Korea, the Ministry of Food and Drug Safety (MFDS)
optimize the procedure and measures for patient radiation
and the Center for Disease Control and Prevention have
protection are needed.
conducted DRL determination studies on various diagnos-
Guidance or recommendations for radiation protection
tic procedures by measurements or surveys.9,10) The scope
in diagnostic radiology are provided by the International
of the investigation for DRL determination ranges from
Commission on Radiological Protection (ICRP). The ICRP
hospital units to regional and national levels. Considering
uses the following approach for radiation protection of
the increased usage of interventional radiology and high
patients. Generally, radiation exposure of a patient dur-
radiation doses, it is necessary to investigate and analyze
ing radiology, such as interventional radiology, is higher
studies on DRL determination for domestic and interna-
than that in daily life; however, the patient also receives
tional interventional radiology in terms of patient radiation
the medical benefits from the procedure. The ICRP states
protection and patient dose management.
that radiation in these areas of medical care must be used
The purpose of this study was to review the DRLs for
for the benefit of the patient and the dose should be opti-
interventional radiology in Korea and abroad. To this end,
mized.3) Summarizing, the basic principle of patient pro-
we first examined the methodology of DRL determination.
tection in medical exposure is to maximize the medical
The radiation dose index and measurement or irradiation
benefits of radiation use while keeping the dose as low as
methodology commonly used in DRL determination for
reasonably achievable considering economic and social
interventional radiology were investigated. In addition,
factors.4-6)
studies on the DRL determination for domestic and inter-
The measured or irradiated radiation dose at a radiological examination facility differs according to the radiologist,
national interventional procedures were examined, and
the results were compared and analyzed.
patient, and hospital, even if the same procedure is used.
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77
Progress in Medical Physics Vol. 30, No. 4, December 2019
Diagnostic Reference Level and Radiation
Dose for a Diagnostic Reference Level
2. Radiation dose for interventional procedure
diagnostic reference level
The measurement or survey methodology for the radia-
1. Diagnostic reference level
tion dose indicator was investigated. The ICRP, InternaIn this study, we investigated the DRL determination
tional Commission on Radiation Units and Measurements
methodology and the radiation dose indicator used to
(ICRU), and IAEA have proposed radiation dose units for
determine a DRL. A DRL may be used as an indicator for
DRLs.6,12,13) The ICRP proposes as conditions of the patient
evaluating how much radiation dose is used for a patient.
radiation dose indicator that the assessment of the amount
DRL determination can be conducted by large-scale ra-
of ionizing radiation used in a procedure and easy mea-
diation dose surveys or measurements across hospitals,
surement or determination of the indicator.6) The ICRU and
regions, or a country. A DRL is generally determined as the
IAEA recommend using a physical quantity that can be
75th percentile level of the measured or surveyed radiation
represented by air kerma as the unit of the radiation dose
dose distribution. It can be applied in various diagnostic
of a DRL.12,13) In general, the dose area product (DAP) and
procedures, such as computed tomography (CT), nuclear
reference air kerma (RAK) are used for the measurement of
medicine, and interventional radiology. Fig. 2 presents an
the radiation dose of a patient in an interventional proce-
example of the radiation dose distribution and DRL. From
dure, because they are easy to be calculated and measured.
Fig. 2, it can be seen that although most radiation doses are
Further, the fluoroscopy time is employed as an additional
low, some are extremely high. The identification and cor-
indicator.
rective actions of facilities or equipment that administer
The concept of DAP is displayed in Fig. 3. The DAP is
abnormally high radiation doses can significantly reduce
defined as the product of the absorbed dose that does not
the radiation dose of a patient. DRL determination should
include the backscattering effects in air measured at the
not end as a one-time event; the DRL needs to be mea-
same distance from the focal point and the area of the X-ray
sured and examined periodically and updated. In the UK,
irradiation field. The DAP can provide information about
where early studies of DRL determination have been con-
the irradiation area in which a patient is actually exposed.
ducted, it has been found that the radiation dose decreases
The intensity of the radiation decreases in inverse propor-
11)
tion to the square of the distance on going further from the
over time.
focal point. In contrast, the irradiation area of the radiation
increases in proportion to the square of the distance; thus,
the above two effects cancel each other. Therefore, the DAP
40
DRL
35
Focus
Counts
30
25
20
15
10
DAP1=A1xDose1
Area1
DAP1=DAP2
5
DAP2=A2xDose2
0
0
5
10
15
Area2
Dose (mGy)
Fig. 2. Dose distributions of diagnostic radiology and diagnostic
reference level (DRL).
Fig. 3. Concept of the dose area product (DAP) measurement.
www.ksmp.or.kr
Min Young Lee, et al：DRL of Interventional Procedures
78
can be defined at any position on the beam axis between
easily collecting information because it does not require a
the X-ray focal point and the patient. It can be derived from
separate measuring equipment. However, the fluoroscopy
direct measurements or calculations. Direct measurement
time can be used only as a reference because it does not re-
of the DAP employs an area dosimeter at the outlet of the
flect the intensity of the injected X-ray, performance of the
X-ray tube. Recently used interventional procedure equip-
device, or irradiation area. Other studies suggest that the
ment utilize the area dosimeter at their outlets or use a
fluoroscopy time alone is not a useful indicator of the dose
calculation formula to display the DAP value employed for
of a patient during a procedure and that we should not ex-
the patient during the procedure on a screen.
amine it separately for patient dose investigation.15-19)
The conceptual diagram of the RAK measurement is
shown in Fig. 4. The RAK is a value indicating the radiation
Nationwide Diagnostic Reference
Level for Interventional Procedures
dose incident on the skin surface of a patient during an
interventional procedure or fluoroscopy. It is measured at
a point in space located at a certain distance from the fo-
1. UK
cal point. In general, in the case of a C-arm, it is measured
at a patient incident reference point 15 cm away from the
In the UK, DRL determination studies on diagnostic
center of rotation on the X-ray beam axis in the focal point
radiology are actively conducted by the Health Protection
direction.14) This incident reference point is similar to the
Agency (HPA). The UK Department of Health and Social
point where the skin of the patient is located, assuming a
Security periodically collects exposure dose information
standard sized patient is lying on the bed. Therefore, the
regarding diagnostic radiology and determines the DRL
RAK can be used to indirectly determine the skin dose
based on the collected data. A DRL determination and
received by a patient. Various terms are used in different
exposure studies for interventional procedures in the UK
organizations to indicate the RAK, such as reference air
were conducted in 2005 and 2010.11,20) In a 2012 study, data
kerma, cumulative air kerma, reference point air kerma,
on various diagnostic procedures, including interventional
and cumulative dose.
procedures and diagnostic radiation, were collected from
The fluoroscopy time is the total time the fluoroscopy
January 2006 to December 2010 at a total of 320 medical
was performed during the interventional procedure. Be-
institutions nationwide for patient dose investigation. This
cause the radiation dose is directly proportional to the time
number represents approximately 25% of the hospitals
of use, the fluoroscopy time is a significant contributor
with diagnostic radiography equipment in the UK. In the
to the exposure dose. In addition, it has the advantage of
UK, data on six major procedures, such as biliary intervention and facet joint injection, were collected. Data were
collected not only on the DAP and the fluoroscopy time,
but also on patient information, such as age and weight.
The information collection for the DAP was based on approximately 15,000 and 14,000 cases of patients, respectively. Each exposure dose information was collected by
Isocenter
of C-arm
Patient
reference point
(RAK)
filling out questionnaires, and the data verification was
Patient
15 cm
DAP meter
Source to
image-receptor
distance
Source to object
distance
performed by a statistical analysis program. Table 1 summarizes the DRL and survey results for the DAP and the
fluoroscopy time during the interventional procedures in
the UK as of 2010.11)
X-ray tube
Fig. 4. Concept of the reference air kerma (RAK) measurement.
DAP, dose area product.
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79
Progress in Medical Physics Vol. 30, No. 4, December 2019
(SIR).21) From 2003 to 2009, these organizations performed
2. USA
a study of the patient dose measurement and evaluation
In the US, medical radiation exposure status surveys
of 21 interventional procedures called “Radiation Doses in
were conducted driven by the Food and Drug Administra-
Interventional Radiology Procedures (RAD-IR) Study”. To
tion (FDA) and the Society of Interventional Radiology
this end, the radiation dose data were collected from a total
Table 1. Dose area products (DAPs) and fluoroscopy times for interventional procedures in the UK (2012)
Radiation
dose unit
DAP (Gy·cm2)
Fluoroscopy
time (s)
Procedure
Biliary intervention
Facet joint injection
Hickman line insertion
Nephrostomy
Oesophageal stent
Pacemaker (permanent)
PTCA 1 stent
Biliary intervention
Facet joint injection
Hickman line insertion
Nephrostomy
Oesophageal stent
Pacemaker (permanent)
PTCA 1 stent
Measurement (n)
Hospital
Room
Patient
10
20
21
24
15
31
14
9
17
18
20
12
24
10
22
30
37
31
24
78
39
21
28
34
25
21
63
35
279
2,720
829
464
199
5,062
5,805
276
2,641
696
332
165
4,475
5,444
Mean
33
4
2
8
13
7
34
687
61
75
399
249
307
516
Minimum Maximum
6
0.2
0.1
0.5
3
0.2
12
147
4
4
57
51
103
84
111
16
10
24
76
34
81
1,116
118
510
1,630
696
670
882
DRL
43
6
3
13
13
7
40
849
84
87
404
298
358
675
DRL, diagnostic reference level; PTCA, percutaneous transluminal coronary angioplasty.
Table 2. Diagnostic reference levels for interventional procedures in the US (2012)
Procedure
Transjugular intrahepatic portosystemic shunt creation
Biliary drainage
Nephrostomy for obstruction
Nephrostomy for stone access
Pulmonary angiography
Inferior vena cava filter placement
Renal or visceral angioplasty without stent
Renal or visceral angioplasty with stent
Iliac angioplasty without stent
Iliac angioplasty with stent
Bronchial artery embolization
Hepatic chemoembolization
Uterine fibroid embolization
Other tumor embolization
Gastrointestinal hemorrhage localization and treatment
Embolization in the head for AVM
Embolization in the head for aneurysm
Embolization in the head for tumor
Vertebroplasty
Pelvic artery embolization for trauma or tumor
Embolization in the spine for AVM or tumor
Number
Dose (Gy)
300
20
12
14
215
40
210
200
300
350
450
300
450
325
425
1,500
1,350
1,700
120
550
1,500
3
1.4
0.4
0.7
0.5
0.25
2
2.3
1.25
1.9
2
1.9
3.6
2.6
3.8
6
4.75
6.2
2
2.5
8
DAP, dose area products; AVM, arteriovenous malformation.
www.ksmp.or.kr
DAP (Gy·cm2) Fluoroscopy time (s)
525
100
40
60
110
60
200
250
250
300
240
400
450
390
520
550
360
550
120
550
950
3,600
1,800
900
1,500
600
240
1,200
1,800
1,200
1,500
3,000
1,500
2,160
2,100
2,100
8,100
5,400
12,000
1,260
2,100
7,800
Min Young Lee, et al：DRL of Interventional Procedures
80
of approximately 2,100 procedures of the medical institu-
approximately 1,400 cases of the procedures were investi-
tions participating in the study. The radiation dose data
gated. Information was collected on the DAP, fluoroscopy
were examined for the DAP, RAK, fluoroscopy time, and
time, patient gender, age, size, and weight. In addition, the
number of images. The age, height, and weight of a patient
information on the level of Complexity of the procedures
were recorded for each procedure performed, and test cas-
(CI) to determine its difficulty was also classified into three
es for each procedure were selected to reduce the devia-
levels (low, medium, and high). However, the study deter-
tion caused by the size of the patient. Thus, approximately,
mined that the number of samples collected was not suf-
1,960 out of the 2,100 cases of procedures were used for the
ficient, and thus, the complexity level was not used. In the
statistical analysis of the data. Table 2 lists the third quartile
investigation, the overall DAP distribution of interventional
DRL values of the DAP and fluoroscopy time for each inter-
procedures was 0.6–1136 Gy·cm2. The fluoroscopy time
ventional procedure analyzed in the study in the US. These
distribution ranged from 0.3 to 80 minutes. The number of
third quartile values are determined as the national patient
digital subtraction angiography (DSA) image distributions
22)
DRLs for US interventional procedures.
ranged from 0 to 893 images. The DRL was set as the third
quartile of the DAP, fluoroscopy time, and number of DSA
images. Table 3 summarizes the results of determining the
3. Spain
interventional procedure DRL in Spain in 2008.
DRL studies in Spain are conducted by the National Soci-
In 2016, the SNSC conducted a study to reestablish the
ety of Interventional Radiology (NSIR) and the Spanish Nu-
DRL.25) In this study, senior interventionists and medi-
clear Safety Council (SNSC). In Spain, patient dose surveys
cal physicists at eight university hospitals were surveyed.
and DRL determination studies for interventional radiol-
Seven procedures, including biliary drainage and hepatic
ogy are conducted under the European Medical Exposures
chemoembolization, were performed, and approximately
23)
Directive, which recommends DRL determination.
1,600 cases were surveyed over three years from 2010 to
In a 2008 study by the NSIR, a survey was conducted with
2013. The DRL was reset to the third quartile of the sur-
interventional radiologists and medical physicists of ten
veyed DAP, fluoroscopy time, and DSA image number
public hospitals nationwide.
24)
The survey was performed
by seven procedures with the highest frequency, including
distribution. Table 4 lists the results of determining the interventional radiology DRL in Spain in 2016.
the biliary drainage and hepatic chemoembolization. Thus,
Table 3. Dose area products (DAPs) and fluoroscopy times for interventional procedures in Spain (2008)
Dose Index
2
DAP (Gy·cm )
Fluoroscopy
time (s)
Procedure
Fistulography
Lower limb arteriography
Renal arteriography
Biliary drainage
Hepatic chemoembolization
Iliac stent
Uterine embolization
Fistulography
Lower limb arteriography
Renal arteriography
Biliary drainage
Hepatic chemoembolization
Iliac stent
Uterine embolization
Number
Maximum
Minimum
Mean
DRL
180
685
55
205
151
70
45
180
685
55
205
151
70
45
83
608
397
428
830
1,136
677
3,120
3,408
1,650
4,764
4,800
4,026
2,670
0.6
2.4
7.7
0.6
27.4
14.1
26.6
18
30
18
36
168
78
18
9
58
75
61
216
91
170
150
180
336
870
1,188
552
1,428
12
73
89
80
289
94
236
150
198
516
1,188
1,458
654
1,818
DRL, diagnostic reference level.
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Progress in Medical Physics Vol. 30, No. 4, December 2019
Table 4. Dose area products (DAPs) and fluoroscopy times for interventional procedures in Spain (2016)
Procedure
Number
Mean DAP
(Gy·cm2)
3th Q DAP
(Gy·cm2)
3th Q fluoroscopy
time (s)
784
37
30
314
56
31
269
62
66
30.8
30.8
189.6
120.2
216.1
83.9
105.7
45
30
214
169
303
119
170
240
336
792
1,038
1,860
2,790
1,578
1,800
1,284
Lower extremity arteriography
Renal arteriography
Transjugular hepatic biopsies
Biliary drainage
Uterine fibroid embolization
Colon endoprostheses
Hepatic chemoembolization
Femoropopliteal revascularization
Iliac stent
Table 5. Dose area products (DAPs) for interventional procedures in Germany (2019)
Procedure
Thrombus aspiration after stroke
(recanalization of cerebral arteries)
Coiling of a cerebral aneurysm
(EVAR of the cerebral artery)
PCI
Combined CA and PCI
TAVI
EVAR
For thoracic aorta
For infrarenal abdominal aorta
For suprarenal abdominal aorta
TACE
PTA
For pelvis
For thigh and knee
For lower leg and food
DAP (Gy·cm2)
Deff (mSv)
25th
50th
75th
DRL
51
91
158
180
11
74
121
192
250
16
20
28
25
34
40
49
49
55
82
48
55
80
9
10
15
47
55
47
62
114
108
95
121
203
203
218
224
230
230
28
32
36
392
22
8
6
44
15
10
87
35
20
90
40
25
23
10
6
DRL, diagnostic reference level; Deff, effective dose; EVAR, endovascular treatment of abdominal aortic aneurysms; PCI, percutaneous
coronary intervention; CA, coronary angiography; TAVI, transcatheter aortic valve implantation; TACE, transcatheter arterial
chemoembolization; PTA, percutaneous transluminal angioplasty.
man Institute of Interventional Radiology (DeGIR), and
4. Germany
AQUA Institute. In Germany, the DRLs were determined
In Germany, research on medical exposure status and
for interventional radiology in 2003, 2016, and 2019 based
DRL determination has been conducted, with focus on
on the collected data.26-28) In 2003, two procedures of the
the Federal Office for Radiation Protection (BfS). The BfS
percutaneous transluminal angioplasty (PTA) and percuta-
revised the radiation-related regulations in 2003 to recom-
neous transluminal coronary angioplasty were set. In 2016
mend the establishment of DRLs in diagnostic radiographs.
and 2019, 12 and 11 procedures were announced, includ-
Since then, periodic investigations and DRL determina-
ing the percutaneous coronary intervention, transcatheter
tion of various medical radiation have been performed.
aortic valve implantation, transcatheter arterial chemo-
The DRL for interventional radiology was set based on
embolization, endovascular treatment of abdominal aortic
numerous databases collected nationally from the “ärz-
aneurysms, and PTA. Table 5 and 6 summarize Germany’s
tliche Stellen” (the Quality Assurance Commission), Ger-
interventional radiology DRL as of 2019.28)
www.ksmp.or.kr
Min Young Lee, et al：DRL of Interventional Procedures
82
by the Radiation and Nuclear Safety Authority (STUK). The
5. Switzerland
STUK measures or evaluates the patient doses every three
Swiss medical radiation survey research is conducted
years to establish the interventional radiology DRL. Fin-
by the Swiss Federal Office of Public Health. In the early
land has presented a DRL for interventional radiology in
2000s, the Federal Office of Public Health, in collaboration
2016.30) In Finland, in interventional radiology and cardiol-
with two university radiation physics laboratories formed
ogy procedures, the difficulty of the procedure may have a
a working group for the radiation protection optimiza-
larger impact on the radiation dose than on the procedure
tion of X-ray examination. The purpose of this group was
steps or procedure equipment. Thus, it is recommended
to generate awareness of the radiation risks to physicians
to use the radiation doses of numerous patients to set the
and radiologists to optimize dose-intensive radiographs. In
DRL and consider the difficulties in the procedure, if nec-
2007, DRL determination was performed for interventional
essary. Table 8 presents the DRL for interventional radiol-
radiology and diagnostic fluoroscopy.29) In this study, ap-
ogy in Finland conducted in 2016.
proximately 1,000 procedures were investigated in the radiology and cardiac disease departments of nine national
and private hospitals for two years. Twelve procedures
7. United Nations Scientific Committee on the
Effects of Atomic Radiation
were investigated in total, and among these, six types of
interventional radiology were examined, including hepatic
The United Nations Scientific Committee on the Effects
embolization, biliary drainage, and stent insertion. The ra-
of Atomic Radiation (UNSCEAR) is an international organi-
diation dose information was examined for the DAP, fluo-
zation established by the United Nations (UN) for the anal-
roscopy time, and number of images. Table 7 presents the
ysis of the effects and risks of radiation on the human body.
29)
UNSCEAR collects information on the medical radiation
DRL for Switzerland in 2007.
exposure doses in all the countries to understand the current status of medical radiation safety management. The
6. Finland
information is gathered by collecting questionnaires from
Research on medical radiation in Finland is conducted
representatives of each country or by researching national
Table 6. Fluoroscopy times for interventional procedures in Germany (2019)
Fluoroscopy time (s)
Procedure
Thrombus aspiration after stroke (recanalization of cerebral arteries)
Coiling of a cerebral aneurysm (EVAR of the cerebral artery)
PCI
Combined CA and PCI
TAVI
EVAR
For thoracic aorta
For infrarenal abdominal aorta
For suprarenal abdominal aorta
TACE
PTA
For pelvis
For thigh and knee
For lower leg and food
25th
50th
75th
720
1,260
312
354
474
1,260
2,040
558
570
720
2,100
3,240
780
780
1,080
420
840
840
660
720
1,260
1,560
1,020
1,140
1,980
3,120
1,500
420
420
540
600
660
1,020
1,020
1,080
1,860
EVAR, endovascular treatment of abdominal aortic aneurysms; PCI, percutaneous coronary intervention; CA, coronary angiography;
TAVI, trans­ca­theter aortic valve implantation; TACE, transcatheter ar­terial chemo­embolization; PTA, percutaneous transluminal angio­
plasty.
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Progress in Medical Physics Vol. 30, No. 4, December 2019
Table 7. Dose area products (DAPs) and fluoroscopy times for interventional procedures in Switzerland (2007)
Category
Diagnostic
Interventional
Combined
Procedure
Fluoroscopy
time (min)
Frame (n)
DAP (Gy·cm2)
7
8
15
10
7
1
30
25
50
25
20
20
20
40
150
480
25
1,400
480
160
30
800
200
1,500
800
2,800
60
210
1,215
150
80
10
620
240
440
460
110
140
260
30
0
280
Barium meal
Lower limb and iliac angiography
Cerebral angiography
Barium enema
Coronary angiography
Electrophysiology
Hepatic embolization
Biliary drainage and stent insertion
Cerebral embolization
Iliac dilatation and stent insertion
Percutaneous coronary intervention
Cardiac thermo-ablation
Coronary angiography+
percutaneous coronary intervention
Electrophysiology+cardiac thermo-ablation
Table 8. Diagnostic reference levels (DRLs) for interventional proce­dures in Finland (2016)
Procedure
Coronary artery examination using a contrast medium
Percutaneous coronary intervention*
Pacemaker installation (excluding CRT pacemaker installation)
Transcatheter aortic valve implantation
Electrophysiological treatment of atrial fibrillation
CRT pacemaker installation
Electrophysiological treatment of atrial flutter
Electrophysiological treatment of atrioventricular nodal reentrant tachycardia
DAP (Gy·cm2)
Fluoroscopy time (min)
30
75
3.5
90
25
22
16
6
4
15
5
19
12
-
DAP, dose area products; CRT, cardiac resynchronization therapy.
*Including potential angiography (ad hoc percutaneous coronary intervention).
research reports and literatures. The UNSCEAR recently
8. Korea
published a report on the results of worldwide medical
radiation exposure surveys obtained from countries and
1)
Survey research on the actual conditions of patient dose
institutions during 1997–2007. In this study, although the
in the interventional radiation procedures in Korea is
interventional radiology DRL was not set, the distributions
actively conducted with the MFDS. The MFDS set a DRL
and differences in the DAPs for different countries at a
based on the collected information of the radiation dose of
particular procedure were analyzed by the UNSCEAR. The
the interventional radiology performed in 2007 and 2012.
UNSCEAR collected the results of the DAP and effective
In the 2012 study, 11 procedures were selected from among
dose evaluation for 30 procedures regarding interventional
the interventional radiology procedures performed in Ko-
radiology according to five major categories of biopsy, bili-
rea, which were relatively numerous procedures or were
ary tract, and urinary system. In the 2010 report, the DAP
of high importance in relation to the radiation protection,
collected from each country was presented in each litera-
including the TACE, arteriovenous fistula (AVF), percuta-
ture. Table 9 lists the distribution of the DAP according to
neous transluminal angioplasty with stent in arteries of the
the interventional radiology reported by the UNSCEAR.
lower extremity (LE PTA and stent). The study collected
patient radiation dose data from the eleven interventional
www.ksmp.or.kr
Min Young Lee, et al：DRL of Interventional Procedures
84
Table 9. Dose distributions for interventional procedures in the United Nations Scientific Committee on the Effects of Atomic Radiation
(2010)
Category
Procedure
Biopsy
Pathological specimen
Biopsy
Small bowel biopsy
Venous sampling
Bile duct drainage
Bile duct dilation/Stenting
Biliary intervention
Biliary duct stone extraction
Lithotripsy
Nephtostomy
Ureteric stenting
Kidney stent insertion
Emboliztion
Management of caricocele
Neuroembolization
Thrombolysis
TIPS
Valvuloplasty
Vascular stenting
Pelvic vein embolization
Insertion of caval filters
Removal of foreings bodies
Coronary angiography
PTCA
Stent procedures
Pacemaker insertion
Uterine fibroid embolization
Feeding tube
Gastrostomy
Diliation/stenting oesophagus
Dilation pyloric stenosis
Colonic stent
Nerve injection
Biliary and urinary systems
Cardiovascular
Uterine fibroid embolization
Gastroinstinal
DAP (Gy·cm2)
Effective dose (mSv)
6
1
38–150
43–54
54
27
5
8–56
18
49
75–114
50.8–131
81–320
13.5
77–524
162
40–42
48
12.7–147
11.8–205
41–166
8.46–19
30.6–298
13
13
15
27
1.7
1.6
1.6
0.26
0.4
9.9–38
11–14
14
7
1.3
2.1–15
4.7
12.7
20–30
6.4–38
2.3–11
3.5
20–87
29
5.8–10
60
13
7
3.1–16
5.4–41
7–13
8–78
3.4
3.4
1.5
7
7
0.2
DAP, dose area products; TIPS, transjugular intrahepatic portosystemic shunt; PTCA, percutaneous transluminal coronary angioplasty.
radiology procedures selected from 24 major hospitals na-
each procedure is found to be 0.01–3081 Gy·cm2 overall,
tionwide. The data surveys were performed according to
with 8.5–1679 Gy·cm2 for the TACE and 0.1–686 Gy·cm2 for
the DAP and fluoroscopy time. In addition, 8,415 domestic
the transfemoral cerebral angiography (TFCA) procedure
data were obtained for each procedure, and the DRL was
reprehensively. The fluoroscopy time distribution is overall
presented as the third quartile of the survey results.
10)
In
2–16,878 seconds, with 32–5,775 seconds for the TACE and
addition, the accuracy of the built-in DAP meter of the IR
16–6,636 seconds for the TFCA procedure reprehensively.
equipment installed in Korea was evaluated, and the actual
Even for the same procedure, the difference is more than
effects of the dose reduction parameters were evaluated by
several hundred times for the performer, patient, and hos-
phantom measurement experiments.
pital. The DRL is set to the third quartile of the DAP and
Table 10 lists the results of the 2012 Korean interven-
fluoroscopy time distributions for each procedure. Repre-
10)
sentatively, the DRLs for the TACE and TFCA are 238 and
tional radiology DRL study.
The DAP distribution for
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85
Progress in Medical Physics Vol. 30, No. 4, December 2019
Table 10. Dose area products (DAPs) and fluoroscopy times for interventional procedures in Korea (2012)
Radiation
dose units
DAP (Gy·cm2)
Fluoroscopy
time (s)
Measurement (n)
Procedure
Hospital
Room
Patient
22
9
13
18
15
15
21
13
15
20
17
22
9
13
18
15
15
21
13
15
20
17
35
14
16
29
18
25
36
15
20
24
17
35
14
16
29
18
25
36
15
20
24
17
3,139
234
278
2,083
320
566
118
219
519
479
460
3,139
234
278
2,083
320
566
118
219
519
479
460
TACE
AVF
LE PTA & Stent
TFCA
Aneurysm coil
PTBD
Biliary Stent
PCN
Hickman
Chemoport
Perm-cath
TACE
AVF
LE PTA & Stent
TFCA
Aneurysm Coil
PTBD
Biliary Stent
PCN
Hickman
Chemoport
Perm-cath
Mean
Minimum
Maximum
DRL
191.1
14.1
85.4
149.6
316.9
36.1
47.4
19
4
2.1
3.7
935.6
649.8
1,090.8
599.9
2,325.5
379.3
606.5
222.9
51.3
34.1
56.3
8.5
0.2
1.3
0.1
35.8
0.3
0.7
0.5
0.03
0.01
0.02
32.0
30.0
42.0
16.0
250.0
16.0
30.0
8.0
5.0
5.0
2.0
1,678.8
113.1
571.0
685.5
3,080.5
1,290.8
289.4
189.1
75.3
31.7
37.4
5,775.0
3,715.0
5,897.0
6,636.0
16,878.0
6,777.0
2,493.0
1,643.0
987.0
428.4
507.0
237.7
17.3
114.1
188.5
383.5
37.5
64.6
22.4
4.3
2.8
4.4
1,224.0
786.1
1,460.4
686.0
2,975.8
427.5
759.8
236.0
54.0
43.0
67.8
DRL, diagnostic reference level; TACE, transcatheter arterial chemoembolization; AVF, arteriovenous fistula; TFCA, transfemoral cerebral
angiography; PTBD, percutaneous transhepatic biliary drainage; PCN, percutaneous nephrostomy.
700
TACE
LE PTA &
stent
PTBD
Biliary stent
PCN
Hickman
insertion
250
500
DAP (Gy cm2)
DAP (Gy cm2)
600
300
Aneurysm coil
embolization
Average
400
300
200
200
150
Average
100
50
100
0
0
KR USA SP 1 SP 2 GE SW KR SP 1 GE KR USA GE SW
2012 2009 2008 2016 2019 2007 2012 2008 2019 2012 2009 2019 2007
KR USA SP 1 SP 2 KR UK SW KR UK USA KR UK
2012 2009 2008 2016 2012 2012 2007 2012 2012 2009 2012 2012
Countries
Countries
Fig. 5. Dose area products (DAPs) for interventional procedures by country. TACE, transcatheter arterial chemoembolization; PTBD,
percutaneous transhepatic biliary drainage; PCN, percutaneous nephrostomy.
189 Gy·cm2 for the DAP and 1,224 and 686 seconds for the
ventional procedures. The domestic DRL is generally low
fluoroscopy time, respectively.
compared to the DRLs in other countries. Comparing the
Fig. 5 and 6 display the comparison of the DAPs and
DRL for the domestic DAP with the average of that in other
fluoroscopy times in domestic and international inter-
countries, the domestic DRL is found to be about two times
www.ksmp.or.kr
Min Young Lee, et al：DRL of Interventional Procedures
86
6,000
TACE
LE PTA &
stent
2,000
Aneurysm coil
embolization
Fluoroscopy time (s)
Fluoroscopy time (s)
5,000
4,000
3,000
2,000
Average
PTBD
Biliary stent
1,800
PCN
Hickman
insertion
1,600
1,400
Average
1,200
1,000
800
600
400
1,000
200
0
0
KR USA SP 1 SP 2 KR UK SW KR UK USA KR UK
2012 2009 2008 2016 2012 2012 2007 2012 2012 2009 2012 2012
KR USA SP 1 SP 2 GE SW KR SP 1 GE KR USA GE SW
2012 2009 2008 2016 2019 2007 2012 2008 2019 2012 2009 2019 2007
Countries
Countries
Fig. 6. Fluoroscopy times for interventional procedures by country. TACE, transcatheter arterial chemoembolization; PTBD, percutaneous
transhepatic biliary drainage; PCN, percutaneous nephrostomy.
lower for the percutaneous transhepatic biliary drainage
DRL setting in domestic and foreign interventional radiol-
(PTBD) and biliary stent procedures. Further, for the TACE
ogy procedures. Further, they were compared and analyzed
and percutaneous nephrostomy (PCN) procedures, it is
to understand the radiation dose exposure status and pa-
approximately 55% and 18% lower, respectively. For the
tient dose management in interventional radiology for the
LE PTA and stent, aneurysm coil embolization, and Hick-
Korean population.
man insertion procedures, it is approximately 30%, 8%,
In Korea, a study on setting the interventional radiology
and 30% higher, respectively. Further, when comparing
DRL was conducted in 2012 by the Ministry of Food and
the DRL for the fluoroscopy time with the average of the
Drug Safety. In this study, DRLs were set for the DAPs and
other countries, the domestic DRL is lower, except for the
fluoroscopy times of eleven procedures, which relatively
LE PTA and stent procedure, which is at a similar level. It
have numerous procedures or are of high importance in
is about approximately thrice lower for the PTBD and PCN
relation to radiation protection. They included the TACE,
procedures and approximately 50% lower for the biliary
AVF, and LE PTA and stent, among interventional radiol-
stent and Hickman insertion procedures. Moreover, it is
ogy performed in Korea. Representatively, the DRLs for the
approximately 30% lower for the TACE and aneurysm coil
TACE and TFCA were 237.7 and 188.5 Gy·cm2, respectively,
embolization procedures, and is similar to that of the other
and for the fluoroscopy time, 1,224 and 686 seconds, re-
countries for the LE PTA and stent procedures.
spectively. When comparing the domestic interventional
radiology DRL with those of other countries, the domestic
DRL was found to be low, in general. When comparing the
Conclusions
DRL for the domestic DAP with the average values of the
The use of interventional radiology is rapidly increas-
other countries, for the PTBD, biliary stent, TACE, and PCN
ing owing to the increase in its demand arising from the
procedures, it was found to be as low as 20% to as high as
average lifespan increase and technology development. It
nearly twice the average values of the other countries. Fur-
is known that interventional radiology takes longer than
ther, for the LE PTA and stent, aneurysm coil embolization,
other radiographies and uses relatively high radiation
and Hickman insertion procedures, it was approximately
doses. Considering the increased usage and high radia-
30%, 8%, and 30% higher, respectively. In addition, when
tion dose of these interventional procedures, the radiation
comparing the DRL for the fluoroscopy time with the aver-
protection of a patient and patient dose management are
age of the other countries, the domestic DRL was lower,
important during interventional procedures. Under these
except for the LE PTA and stent procedures, which were at
circumstances, we investigated the current status of the
similar levels.
www.ksmp.or.kr
Progress in Medical Physics Vol. 30, No. 4, December 2019
Interventional radiology, as medical radiation exposure,
87
1991.
benefits a patient and is an important procedure that is di-
4. ICRP Publication 73: Radiological protection and safety in
rectly related to the life of a patient; thus, it is not appropri-
medicine. Ottawa: International Commission on Radio-
ate to perform extremely strict management of the radia-
logical Protection; 1991.
tion exposure that a patient receives without considering
5. ICRP Publication 105: Radiological protection in medi-
the overall circumstances. However, to optimize the proce-
cine. Ottawa: International Commission on Radiological
dure and reduce patient dose, it is necessary to understand
Protection; 2007.
the current status of domestic patient dose management
6. ICRP Publication 135: Diagnostic reference levels in medi-
by investigating the patient exposure level and DRL setting
cal imaging. Ottawa: International Commission on Radio-
during the interventional procedure. In the future, if the
logical Protection; 2017.
nationwide survey is continuously conducted for medical
7. ICRP Supporting Guidance 2: Radiation and your patient:
radiation safety management and patient protection, it will
a guide for medical practitioners. Ottawa: International
ultimately contribute to maximizing the benefit to patients
Commission on Radiological Protection; 2002.
from interventional radiology while minimizing the radiation dose of the patient.
8. IAEA Safety Series No. 115: International basic safety standards for protection against ionizing radiation and for the
safety of radiation sources. Vienna: International Commission on Radiological Protection; 1996.
Acknowledgements
9. Evaluation of patient dose in interventional radiology.
This work was supported by the Nuclear Safety Research
Seoul: Ministry of Food and Drug Safety; 2007.
Program through the Korea Foundation of Nuclear Safety
10. Evaluation of patient doses from interventional radiol-
(KoFONS) using the financial resource granted by the
ogy procedures. Seoul: Ministry of Food and Drug Safety;
Nuclear Safety and Security Commission (NSSC) of the Re-
2012.
public of Korea (No. 1803013).
11. HPA-CRCE-034: Doses to patients from radiographic and
fluoroscopic x-ray imaging procedures in the UK - 2010
review. London: Health Protection Agency; 2012.
Conflicts of Interest
12. ICRU Report 74: Patient dosimetry for X rays used in medi-
The authors have nothing to disclose.
cal imaging. Bethesda: International Commission in Radiation Units and Measurement; 2005.
13. IAEA Technical Report Series No. 457: Dosimetry in diag-
Availability of Data and Materials
nostic radiology: an international code of practice. Vienna:
All relevant data are within the paper and its Supporting
Information files.
International Atomic Energy Agency; 2007.
14. IEC 60532: Radiation protection instrumentation - installed dose rate meters, warning assemblies and monitors
- X and gamma radiation of energy between 50 keV and 7
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