first dose values in interventional procedures. a pilot investigation in

BEDOYA R. ET AL.
ARTÍCULO DE INVESTIGACIÓN
FIRST DOSE VALUES IN INTERVENTIONAL PROCEDURES. A
PILOT INVESTIGATION IN PANAMA
RESUMEN
El propósito del estudio fue establecer para pacientes adultos, los primeros niveles referenciales diagnósticos
(NRDs) en procedimientos intervencionistas cardiológicos (IC) y no cardiológicos (INC) en Panamá.
Se trabajo en el principal hospital del seguro social del país, donde se registro para cada procedimiento, el
tiempo de fluorosocopia (TF), el producto dosis area (PDA) y la dosis acumulativa (DA).
El estudio incluyo a 188 pacientes sometidos a procedimientos IC. Los resultados obtenidos mostraron que el
rango de TF usado fue desde 9,85 a 19,37 min. El rango de valores para el PDA fue desde 11,02 a 21,60 Gycm2
y, el rando de la DA fue desde 1,43 a 2,88 Gy.
Además, se incluyo una segunda muestra de 208 pacientes, sometidos a procedimiento INC. Los procedimientos
fueron categorizadas en tres regiones anatómicas: cabeza, tórax y abdomen. El respectivo rango de valores para
el PDA, TF y DA en cabeza fueron 1,099 a 248,82 Gy cm2, 7 a 34 min y 0,41 a 12,79 Gy, respectivamente. El
respective rango de valores para el PDA, TF y DA en tórax fueron 99 a 8642 Gy cm2, 0,21 a 22,52 min y 0,007
a 0,418 Gy, respectivamente. El respective rango de valores para el PDA, TF y DA en abdomen fueron 0,22 a
36,71 Gy cm2, 1,03 a 76,06 min y 0,018 a 7,39 Gy, respectivamente.
CORRESPONDENCIA
Raquel Bedoya1
Maria Fernandez2
1.Radiation
Petaquilla
Panama.
Protection Officer,
Gold,
Panama,
2.Radiation
Protection
Officer,
Hospital Santo Tomas, Panama,
Panama.
Correo autor:
bedoya_raquel@hotmail.com
Este trabajo, representa un primer esfuero para establecer (NRDs) en procedimientos IC y NIC. Se recomienda ampliar la muestra de hospitales y
procedimientos.
Palabras claves: Niveles referenciales diagnósticos, procedimientos intervencionistas, producto dosis area.
ABSTRACT
The objective of this study was to establish the first diagnostic reference levels (DRLs) for adult patients in interventional cardiology (IC) and noncardiological (NIC) procedures in Panama.
The study was carried out in the country’s leading public hospital. Fluoroscopy time (FT), dose area product (DAP) and cumulative dose (CD) were
recorded for each procedure.
The study included 188 patients subjected to IC procedures. The results obtained showed that FT ranged from 9.85 to 19.37 min. The range of DAP values
was from 11.02 to 21.60 Gy cm2, and CD values ranged from 1.43 to 2.88 Gy.
A second sample of 208 patients, subjected to NIC procedures, was also included. The procedures were categorized by three anatomical regions:
head, thorax and abdomen. The respective ranges of values for DAP, FT and CD for head were: 1.099 to 248.82 Gy cm2, 7 to 34 min and 0.41 to 12.79
Gy, respectively. The respective ranges of values for DAP, FT and CD for thorax were: 99 to 8642 Gy cm2, 0.21 to 22.52 min and 0.007 to 0.418 Gy,
respectively. The respective ranges of values for DAP, FT and CD for abdomen were: 0.22 to 36.71 Gy cm2, 1.03 to 76.06 min and 0.018 to 7.39 Gy,
respectively.
This study represents an initial attempt to establish DRLs in IC and NIC procedures. It is recommended to broaden the sample of hospitals and procedures.
Keywords: Diagnostic reference levels, interventional procedures, dose area product.
INTRODUCTION
The interventional cardiology (IC) and interventional non
Particularly, the IC procedures are associated with high
cardiology (INC) procedures have increased substantially
radiation dose, due to the long fluoroscopy time (FT) and
in the last years, becoming a subject of public health.
to the great number of cine frames (1). High radiation doses
Rev. cienc. salud med. Volumen 3, Número 2, Mayo de 2016.
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FIRST DOSE VALUES IN INTERVENTIONAL PROCEDURES. A PILOT INVESTIGATION IN PANAMA
ARTÍCULO DE INVESTIGACIÓN
during IC procedures affect the patients, as well as, to the
MATERIALS AND METHODS
medical personnel.
An interventional X ray system with digital flat panel
The patients can undergo erythema and other damages to
used in the IC and INC procedures was used during the
the skin
. These injuries can to arrive to be severe until
investigation: General Electric Innova 3100. X ray system
point which sometimes the patient presents ulcerations or
was equipped with an ionization transmission chamber
necrosis at level of the tissue, which they require treatments
integrated into the collimator housing to measure dose–
prolonged for the injurious and irreversible effects of the
area product (DAP), equivalent to air kerma-area product (6).
radiation, in addition to the increase of the long term
Different dosimetric quantities are displayed on the in-room
probability to develop some neoplasy .
monitors. In addition to the DAP, cumulative dose (CD) is
(2)
(3)
also shown. This quantity is referred to in the standard IEC
Radiation injury has occurred in patients during complex
60601-2-43 as equivalent to the incident air kerma without
interventional procedures cardiac and non-cardiac, have
backscattering at the patient entrance reference point (7).
been severe. During these procedures the patients have
received more than 2 Gy at the skin. But the dangerous
The X-ray system was evaluated in terms of dose and quality
is a large number of patients that are not followed up after
image. The performance tests were: potential accuracy or
received this radiation dose .
tube potential (kV),
(3)
tube current (mA), maximum dose
rate, automatic compensation, high contrast resolution and
For medical exposition is not dose limit applied to the patient,
low contrast detectability, applying the Spanish protocol
nevertheless, is important to determine if the radiation dose
and Protocol for the Quality Control Radiodiagnostic
that these receives during the interventional procedures
OIEA/ARCAL XLIX
are excessive or not, considering the thresholds established
semiconductor detector UNFORS IX (6, 10) and Al20 phantom.
for the appearance of effects or injuries in the organism
The Al20 phantom was composed of 2 absorber aluminium
due to radiation or comparisons with diagnostic reference
equivalent. The plate has 10mm of thickness, a copper
levels (DRLs) established in other populations. DRLs as
and lead absorber of 2mm thickness. For high contrast
measurable values have been defined in publications of the
resolution used the Nuclear Associates 07-647 RF/QC test
International Commission of Radiological Protection (ICRP)
tool and for the detectability low contrast was used the RMI-
and in the Basic Security Norms (BSN) No. 115
151-3585
(4, 5)
, allow
(11)
(8, 9)
. Tests were performed using a
. The tests realized for quality image focused
of direct way to verify situations where dose levels to the
in the monitor, to determine the capacity to solve as very
patient are exceptionally high. The ICRP recommends that
small anatomical structures as the blood vessels.
DRLs be used to optimize patient doses. By previous and
considering the need establish these levels, the objective
After, the performance tests to X ray system the
of our work was to the establishment of the first DRLs in the
methodology on national surveys recommended by the
IC and INC studies made in Panama, for indirectly to avoid
European Commission Consortium’s “Safety and Efficacy
the appearance of the determinist effects protecting of that
for New Techniques and Imaging Using New equipment
form to the patient and paramedical staff exposure In order
to Support European Legislation” (SENTINEL) has been
to carry out this, also the performance of each x-ray system
followed. The following data were recorded from each
was verified.
procedure: procedure identification, patient age, gender,
Rev. cienc. salud med. Volumen 3, Número 2, Mayo de 2016.
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BEDOYA R. ET AL.
ARTÍCULO DE INVESTIGACIÓN
fluoroscopy time (FT), DAP and CD.
in this study and others authors.
Statistical calculations for patient dose values were
performed with the SPSS 17 software package
(12)
.
DISCUSSION
Differences between two independent (normally distributed)
samples were tested for significance with the One Simple T
In terms of the measurements made, it was found that the
Test (95% confidence level).
accuracy potential and maximum dose rates were within
acceptable ranges (see Tables 1).
The Panamanian norm that contemplates to the check of
RESULTS
the equipment performance for the generators radiation
is the Basic Norms of Protection No. 110, Resolution
Table 1 report the performance parameters evaluated in the
No. 27 of the 24 of October of 1995 in their Section 3a
X ray system. The top group of pair lines that can be solved
on “Optimization of the Protection relative to the exposure
in the monitor was 11 that correspond to 2.5 pl/mm and 5
medical exhibitions”. Protocols of evaluation were prepared
mm, 4 mm and 2 mm and can be observed the two rows of
based on recommendations of the International Agency
parallel circles which they correspond to 6 mm of diameter.
of Energy Atomic (IAEA) and the American College of
Radiology (ACR) in relation to the tests of performance and
Table 2 show a comparison of the DAP, FT and CD between
criteria of tolerance (13).
diagnostic and therapeutic procedures in IC.
Of the 188 evaluated studies to adult patients, 137 were
Table 3 report a comparison between the percentile 75 of
masculine patients, which represent 73% and 51 feminine
DAP values in IC procedures in this study and others works.
patients with a 27%. This is very agreed to which they
mainly reflect the statistic registered in the country for
The table 4 showed the comparison of the DAP, FT and CD
causes of death by ischaemic diseases the heart and in
between anatomical regions in INC.
masculine sex
(14)
, by the behavior according to the sort in
the lifestyles and attention of health. The women are put
The tables 5, 6 and 7 showed the comparison of DAP, CD
under with more regularity health controls that the men and
and FT between anatomical regions for in INC procedures
have more healthful lifestyles.
Table 1: Performance tests of the X ray system General Electric, Innova 3100.
Performance
Test*
Accuracy Potential
maximum dose rate
Values obtained
kVpanel
kVmeasured
mApanel
mAmeasured
60
60
0.75
0.752
70
70
1.50
1.495
80
80
3.00
3.001
100
100
9.00
8.995
120
100
12.00
12.004
120
120
120
120
* For compensate used a phantom Al20 of 20mmAl + 2mm Cu thickness
Acceptance criteria
Results
Conformity
5%
0%
Yes
0.27%
≤10R/min
9.80R/min
**2.18mGy/s more or less 4.16R/min
Rev. cienc. salud med. Volumen 3, Número 2, Mayo de 2016.
22
9.51R/min
Yes
FIRST DOSE VALUES IN INTERVENTIONAL PROCEDURES. A PILOT INVESTIGATION IN PANAMA
ARTÍCULO DE INVESTIGACIÓN
For IC was evaluated 188 procedures, of which 150 cardiac
European studies (16, 17, 18), in some were the double.
catheterizations diagnostic and 38 therapeutic of coronary
For the values of FT was not observed statistically significant
angioplasty and positioning of stent. Of the procedures
difference (p=0.08) between the diagnoses and therapeutic
diagnoses 46 they correspond to feminine patients and 104
procedures, in the same way the results of DAP and the
to masculine, whereas for therapeutic the 5 of feminine sex
CD statistically significant differences with values of p=0.10
and 33 masculine.
and p=0.09 either respectively (Table 2).
In its majority the cardiological procedures that took end
Table 2: Comparison of the DAP, FT and CD between diagnostic and
was the denominated cardiac catheterization for the
therapeutic procedures in IC.
diagnostic evaluation of the cardiac muscle and sometimes
Parameter
it finished in treatment during the same session, in which
the FT is much greater.
The obtained values of DAP and FT varied between
procedures, that variation can be attributed to the capacity
General Electric Innova 3100
Procedure
Procedure
Sig (p)
Diagnostic
therapeutic
FT (min)
11.02
21.60
0.08
DAP (Gycm2)
9.85
19.37
0.10
CD (Gy)
1.43
2.58
0.09
and skill of physicians, the complexity of the procedure and
In addition, of the comparison of the mean DAP values,
application of attention protocols.
the values of the percentile 75 for the diagnostic and
therapeutic examinations of this study were compared with
The CD for studies realized in the equipment this value fall
the values of international works, which were smaller to the
within the range of threshold reported for the appearance
referenced (18 - 21) how are given in Table 3.
of opacity crystalline in a single irradiation (0.5 – 2.0 Gy)
for humans, deduced of accidental and radiotherapy
expositions
(15)
Table 3: Comparison between the percentile 75 of DAP values in IC
. Although, in the IC the irradiated region
mainly is the thorax, and INC
studies realized like the
procedures in this study and others works.
Neofotistou
Tsapaki
Balter
Sánchez
This
cerebral procedures, that in their mayority finish in the
Procedure
et al.
et al.
et al.
et al.
work
phase of treatment for example the angiosplaty with
[19] (2003)
[18]
[20]
[21]
(2012)
embolization and positioning of coils, where the ocular
(Gycm2)
(2003)
(2008)
(2011)
(Gycm2)
surface was irradiated directly.
It is important indicate, that this mean value of 1.43 Gy for
(Gycm2)
(Gycm2)
(Gycm2)
Diagnostic
45.0
60.4
50.0
44.0
12.42
Therapeutic
75.0
80.7
125.0
78.0
25.87
the CD in the cineangiograph, increased the probability
of deterministic effects in the skin and significant risk of
As it were to be expect the therapeutic cardiological studies
appearance of cancer induce like effect stochastic, since
presented the values of FT, DAP and CD greater in relation
has been demonstrated firmly for dose from the 100 mGy
to the studies diagnostic. For DAP and CD the values were
is an increase of the probability of deterministic effects and
almost the double.
the risk of cancer by radiation (15).
For the CD of 1.43 Gy in IC procedures, almost represents
The results of the mean FT for cardiological studies
the double in relation to the mean value reported (17). But, it
diagnostic in adults was greater to the values considered in
does not reach the value of the threshold of 2 Gy after the
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BEDOYA R. ET AL.
ARTÍCULO DE INVESTIGACIÓN
erythema or reddening of the skin. But it observed in the
registered by other referenced authors and a 50% minor
collected data some studies with prolonged FT values of
that Miller et al (22).
entrance surface air kerma superior to this threshold.
How showed in the Table 6, the comparison of the percentile
Of total 208 INC procedures was analyzed, 23 were realized
75 values CD obtained in this study for the head was major
at the region of the head which represented a 11.06%, 34
(6.73 Gy). The region of the abdomen which was of 1.13 Gy
were realized at the abdomen (16.35%), were at the region
compared with the IAEA reference (23) was 1.5 times greater
of the thorax (0.043%) and 142 extremities (68.27%).
and 1.7 times smaller comparing with Miller (22).
98 procedures corresponded to feminine sex, which
For the FT values reported in this study (Table 7), the
represented a 47.12% and 110 to masculine sex what was
anatomical region that registered major value was at
a 52.88%. The average as far as the age was of 64.05
the head (20.29 minutes). But this value was minor with
years.
reference to the other works (22, 23).
In the Table 4 observed that for DAP, FT and CD the
Table 4: Comparison of the DAP, FT and CD between anatomical regions for INC.
Anatomical region
Head
Abdomen
Thorax
DAP (Gycm2)
CD(Gy)
FT (min)
Mean, median
Mean, median
Mean, median
(range)
(range)
(range)
220.54; 120.24
1.94; 0.99
15.23;13.18
(1.099 -248.52)
(0.41 – 12.79)
(7 - 34.00)
50.00; 22.60
0.63; 0.17
15.16;8.20
(0.22- 36.71)
(0.018 – 7.39)
(1,03 – 76,06)
24.55; 12.76
0.16; 0.05
11.54 ; 7.81
(99.00 – 8642.00)
(0.007 – 0.418)
(0.21 -2252)
highest values was obtained in the region of the head with
Table 5: Comparison of DAP between anatomical regions for in INC
220 Gy.cm2, 15.03 minutes and 1.94 Gy respectively. For
the abdomen values were major that the thorax. However,
it does not reach the value of the threshold of 2 Gy as the
procedures in this study and others works.
Authors
DAP (Gycm2)
Abdomen
IC procedures, but some procedures showed FT values
D. Miller, 2009[26]
prolonged of entrance surface air kerma superior to this
IAEA-Vienna [23]
210.50
Head
Thorax
141.25
296.00
-
97.22
threshold.
Table 6: Comparison of CD between anatomical regions for in INC
A comparison of the percentile 75 values DAP obtained by
anatomical region was observed that in the head registered
procedures in this study and others works.
Authors
greater value (161.59 Gy.cm2). For the abdomen was 40.32
CD (Gy)
Abdomen
Head
Thorax
3.12
Gy.cm2 and thorax 43.57 Gy.cm2, However compared with
D. Miller, 2009[26]
1.93
5.65
the results of others authors in countries like Chile, the USA
IAEA-Vienna [23]
0.75
1.13
and Austria, this value at the head was inferior to the data
Rev. cienc. salud med. Volumen 3, Número 2, Mayo de 2016.
24
FIRST DOSE VALUES IN INTERVENTIONAL PROCEDURES. A PILOT INVESTIGATION IN PANAMA
ARTÍCULO DE INVESTIGACIÓN
These obtained results constitute a significant step for the
the skin, nevertheless for therapeutic the mean doses that
establishment of the DRLs in the country, which require
were observed over 2 Gy. This implies that the probability
extending the data summary as much for diagnostic and
was high that during an interventionist study in these rooms
therapeutic procedures.
of haemodynamic a patient suffered damages by exposure
to the radiation and the probability of stochastic effects
Table 7: Comparison of FT between anatomical regions for in INC
incremented also. With the collect data the base settled
procedures in this study and others works.
down to initiate the task of establishment the DRLs in the
Authors
country. But, it is necessary to extend the amount of data
TF (minutes)
Abdomen
Head
Thorax
D. Miller, 2009[26]
25.10
142.00
52.75
IAEA-Vienna [23]
18.82
31.25
and include more equipment and other hospitals.
ACKNOWLEDGMENTS
I acknowledge to Dr. Eloy Gibbs by the support offered.
CONCLUSIONS
For the X ray equipment used in the interventional studies
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