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SEMINAR 1Radiological Protection Of PatientsRadiological Protection Of Patients
Radiation Protection in Paediatric Cardiology
Dra. Patricia Miranda González
CARDIOVASCULAR DEPARTMENT , CALVO MACKENNA’S HOSPITAL SANTIAGO CHILE
Radiation Protection in Paediatric Cardiology
Pediatric patients have special features, they are not small adults.
Radiation Protection in Paediatric Cardiology
Paediatric cardiology is absolutely different from the adult cardiology not only in the age of the patients (newborns until fifteen years old) but also because of the diversity of structural anomalies in congenital heart diseases
• This is important to understand because paediatric procedures are longer than procedures in adults (Lock 2000).
• In certain times need to be studied before each surgery, even up to three times before the age of two years old.
• More complex congenital heart diseases have the possibility of cardiac surgery, complex diagnostic studies are necessary including several biplane angiographic recordings, measurement of local pressure curves and oxygen saturation (with and without oxygen), before and after cardiac surgery.
PART 1
1. They have congenital diseases of the heart
Mean values of Pka for different procedures
Type of examination Pka Gycm²mean
Pulmonary angioplasty with stent 8.10
Diagnostic complex (D) 6.47
Closure atrial septal defect 5.14
Other 4.54
Aortic valvuloplasty 3.63
Pulmonary angioplasty 3.56
Diagnostic “normal” (d) 3.46
Therapeutic (global) 3.44
Aortic angioplasty 2.98
Diagnostic (global) 2.44
Pulmonary valvuloplasty 2.00
Patent ductus arteriosus closure. 1.27
Radiation Protection in Paediatric Cardiology
A PILOT PROGRAMME ON PATIENT DOSIMETRY ON PAEDIATRIC INTERVENTIONAL CARDIOLOGY IN CHILE
Radiation Protection in Paediatric Cardiology
2. Children have especially radiosensitive tissues
Radiation Protection in Paediatric Cardiology
Dosis
Efec
t
Deterministic Deterministic efectefect
Cancer and Genetic efects
Probability ∝ dosis
EstocasticEstocastic(Probabilistic)(Probabilistic)
RxRx
CataratasEsterilityEritemaEpilationFetal Malformations
Radiation Protection in Paediatric Cardiology
3. Their have longer life span makes the stochastic effect manifest
674 childrens undergoing cardiac catheterization due to congenital heart desease between 1950-1970 The expected number of cancer was 4.75, but the real number was 11.0
Radiation Protection in Paediatric Cardiology
Dosis
Efec
t
Deterministic Deterministic efectefect
CataratasEsterilityEritemaEpilation
Fetal Malformations
Cancer and genetic efects
Probability ∝ dosis
EstocasticEstocastic(Probabilistic)(Probabilistic)
RxRx
Radiation Protection in Paediatric Cardiology
According to the International Commission Radiological ptrotection (ICRP)the probability of cancer iduction by ionizig radiation is a factor 2-3 higherfor infants and children in comparision with adults (ICRP 1991).
0,00
0,04
0,08
0,12
0,16
0,20
0 15 30 45 60 75 90
Edad de exposicion
Muerte por
Sievert (Sv)
FemaleMale
Radiation Protection in Paediatric Cardiology
4. The age of the patients is very different (newborns until fifteen years of age) even their weight.
Air kerma area product retains a strong dependence on patient weight
kerma area product v/s body weight
y = 78,531e0,4495x
R² = 0,8974, R=0,9473
0
100
200
300
400
500
600
700
800
900
< 10 10 ‐ 20 20 ‐ 30 30 ‐ 40 > 40Weight (kG)
kkerma area
produ
ct KAP (cGycm^2
A PILOT PROGRAMME ON PATIENT DOSIMETRY ON PAEDIATRIC INTERVENTIONAL CARDIOLOGY IN CHILE
Radiation Protection in Paediatric Cardiology
Kerma area product per minute fluoroscopy versus body weight
FLUOROSCOPY
y = 2.3857e0.4386x
R2 = 0.9994
0
5
10
15
20
25
< 10 10 ‐ 20 20 ‐ 30 30 ‐ 40 > 40Weight (kG)
kerm
a area
pro
duct / tim
eflu
oros
copy
(cGycm^2
min‐ 1
Kerma area product per cine frame versus body weight
CINE ACQUISITION
y = 0.0356e0.5386x
R2 = 0.9863
0
0.1
0.2
0.3
0.4
0.5
0.6
< 10 10 ‐ 20 20 ‐ 30 30 ‐ 40 > 40Weight (kG)
kerm
a area
pro
duct / fr
ame
(cGycm^2
)
A PILOT PROGRAMME ON PATIENT DOSIMETRY ON PAEDIATRIC INTERVENTIONAL CARDIOLOGY IN CHILE
Radiation Protection in Paediatric Cardiology
A PILOT PROGRAMME ON PATIENT DOSIMETRY ON PAEDIATRIC INTERVENTIONAL CARDIOLOGY IN CHILE
Radiation Protection in Paediatric Cardiology
HDO Biplane A 11Nov04 paediatric
0
50
100
150
200
250
4 8 12 16 20
cm PMMA
mic
roG
y/fr
ame
Cine 25 cmCine 20 cmCine 16 cm
Radiation Protection in Paediatric Cardiology
RADIATION DOSE AND IMAGE QUALITY FOR PAEDIATRIC ITERVENTIONAL CARDIOLOGY E. Vañó. C. Ubeda. F Leyton and P. MirandaPublished 8 july 2008
Radiation Protection in Paediatric Cardiology
PART 2
Paediatric Interventional Cardiology (PIC) has a challenge¿ How to reduce the doses in PIC?
1. Formation in RP
Radiation Protection in Paediatric Cardiology
Support Programs of the IAEA
• Regional Workshops in Chile 2006 and Costa Rica 2007.
• Attending cardiologist from all Latinamerica.• Several works at the workshop to evaluate
patient dose in interventional Cardiology in Latin America.
Radiation Protection in Paediatric Cardiology
2. The equipment
¿What is the best Image intesifier or Flat Panel?
Both sistems are adecuated, but flat panel have became the most “popular” because the market offers a better image quality and dose reduction, nevertheless the experince show that at least at this “inicial point” is different.
Radiation Protection in Paediatric Cardiology
Biplane Siemens Flat panel
Biplane Siemens with image itensifiers
Radiation Protection in Paediatric Cardiology
Dose rate reaching the
patient is meassured or
calculated (usually expresed
in mGy/min)
Radiation Protection in Paediatric Cardiology
Flat Panel sistemDose rate reaching
the metacrilatpatient is
meassured or calculated (usually
expressed in mGy/min)
Radiation Protection in Paediatric Cardiology
3. Operation modes
Sometimes, interventionists do not have clear criteria to select
the different operation modes. Thus, the characterization of the
systems in dose and image quality using test objects offers a set
of useful data to help cardiologists to select the most appropriate
operation modes for the different procedures and patient sizes.
Radiation Protection in Paediatric Cardiology
RADIATION DOSE AND IMAGE QUALITY FOR PAEDIATRIC ITERVENTIONAL CARDIOLOGY E. Vañó. C. Ubeda. F Leyton and P. MirandaPublished 8 july 2008
Radiation Protection in Paediatric Cardiology
RADIATION DOSE AND IMAGE QUALITY FOR PAEDIATRIC ITERVENTIONAL CARDIOLOGY E. Vañó. C. Ubeda. F Leyton and P. MirandaPublished 8 july 2008
Radiation Protection in Paediatric Cardiology
0
10
20
30
40
50
16 20 24 28PMMA thickness (cm)
Scat
ter d
ose
rate
(mSv
/h)
lowmedhighcine
Radiation Protection in Paediatric Cardiology
Important factors in the dose rate for fluoroscopy
• Number of pulses per second (pulsed fluoroscopy).• Dose per puls (o dose per “frame”).• Added Filter (normaly the low dose modes use cupper
filters of 0,4 to 0,8 mm).
Radiation Protection in Paediatric Cardiology
HDO Biplane A 11Nov04 paediatric0.
2
0.3 0.7 1.
4
3.4
0.3 0.6 1.
3 3.1
7.4
0.5 1.
5 2.8
6.7
17.3
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
18.0
20.0
4 8 12 16 20
cm PMMA
mG
y/m
in Fluoro low 25 cmFluoro med 25 cmFluoro high 25 cm
Radiation Protection in Paediatric Cardiology
HDO Biplane A 11Nov04 paediatric vs adult
3.4
7.4
17.3
4.5
11.7
21.6
0.0
5.0
10.0
15.0
20.0
25.0
20
cm PMMA
mG
y/m
in
Fluoro low 25 cmFluoro med 25 cmFluoro high 25 cmFluoro low adultFluoro med 25 cm adultFluoro high 25 cm adult
Radiation Protection in Paediatric Cardiology
CD-1 1 fluoro 5860895
Radiation Protection in Paediatric Cardiology
CD-1 4 cine 5861107
Radiation Protection in Paediatric Cardiology
Comparison between median KAP (Gy.cm2) for paediatric cardiology procedures reported by different authors (figures adapted by theauthors of this paper).
Age bands (years)
Boothroyd et al.
[10] (1997)
Rassow et al. [11]
(2000) (Gycm²)
Bacher et al. [12]
(2005) (Gycm²
)
Martinez et al. [7] (2007)
(Gycm²)
*This paper (2008)
(Gycm²)
<1 12 3 1.9 1.01 - < 5 24 5 4.1 2.9 1.65 - < 10 48 10 4.5 1.810 - <16 98 18 15.4 5.1
*A PILOT PROGRAMME ON PATIENT DOSIMETRY ON PAEDIATRIC INTERVENTIONAL CARDIOLOGY IN CHILE
Radiation Protection in Paediatric Cardiology
Pediatric interventional cardiologyst dose
HDO Biplane A 11Nov04 paediatric
0
1
2
3
4
5
6
4 8 12 16 20
cm PMMA
mS
v/h
Fluoro low 20 cmFluoro med 20 cmFluoro high 20 cmcine 30f/s 20 cm
Radiation Protection in Paediatric Cardiology
Different C-arm angulations can modify the disperse dose in a 5factor
Radiation Protection in Paediatric Cardiology
Operation modes tips
1. Use of fluoroscopy runs instead of cine
2. Use of “one shot” instead of cine
3. Use one projections instead of two if it is possible (PDA
closure with coil)
Radiation Protection in Paediatric Cardiology
4. Reduce the operator doses
SUGGESTED ACTION LEVELS FOR STAFF DOSE
Body 0.5 mSv/monthEyes 5.0 mSv/monthHands/Extremities 15.0 mSv/month
Suggested action levels in staff exposure in interventional radiology (Joint WHO/IRH/CE workshop 1995)
References:• Radiation Safety in Interventional Radiology: BfS ISH 178/97. Proceedings of the 1995 Joint WHO/ISH Workshop. October 9-13; Munich-Neuherberg. Bundesamt für Starhlenschutz, Germany. 1997.• Efficacy and Radiation Safety in Interventional Radiology. WHO 2000. Geneva.
Radiation Protection in Paediatric Cardiology
Lens dose, optional Finger dose, optional Second dosemeteroutside and above the apronat the neck, optional
Personal dosedosemeter behind the lead apron
X-ray tube
Image intensifier
Patient
Radiationprotectionmeasures
Dose limits of occupational exposure
(ICRP 60)
Effective dose 20 mSv in a yearaveraged over a period of 5 years
Anual equivalent dose in the lens of the eye 150 mSvskin 500 mSvhands and feet 500 mSv
Radiation Protection in Paediatric Cardiology
Reduction in operator doses with the use of radiation protection tools
• Lead apron of 0.5; 0.35 or 0.25 mm lead equivalent (weight of the apron to be taken into account). Typical reduction 90% (or more).
• Thyroid protector. 0.5 mm lead equivalent
• Suspended ceiling screens, typically equivalent to 1 mm lead. Typical reduction > 90%.
• Under table lead equivalent protection
• Protective goggles, typically 0.5-0.75 mm lead.
• Tactile gloves, typically equivalent to 0.03 mm lead. Typical reduction > 15-55%.
Radiation Protection in Paediatric Cardiology
0.50 mm lead
60 kV; 100% < 1 %
100 kV; 100% 3 - 7 %
Attenuation measured at the San Carlos University Hospital (lead aprons)
But, X ray beam filtration has a great influence!!
Radiation Protection in Paediatric Cardiology
THYROID PROTECTOR
Avoid more than 90% of the scatter radiation
Radiation Protection in Paediatric Cardiology
Sometimes, hands in the
direct beam!!
Radiation Protection in Paediatric Cardiology
Vañó et al.Br J Radiol 1998;
71:954-960
Interventional cardiologist
Interventional radiologist
Mean values (µSv) per procedure
(using protection tools)
Radiation Protection in Paediatric Cardiology
Give me a break !!!