A survey of radiation dose to patients and
medical staff during different diagnostic
procedures using TLD dosimetry
Kiki Theodorou, PhD
Assistant Professor on Medical Physics
Medical Physics Department
Medical School, University of Thessaly
Aims of the study
1.
2.
3.
4.
TLD calibration for dose measurement
of low energy x-rays
Dose measurement for different
radiological procedures
Determination of local Dose Reference
Levels (DRLs) for those procedures
Risk assessment for patients, staff and
accompanying persons
Dose monitoring in Diagnostic
Radiology

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Calculation of organ’s effective
dose
Risk calculation
Determination of Dose
Reference Levels (DRLs)
Dose optimization to patients
and staff
Is the law!
Means of Patient Dosimetry in
Diagnostic Radiology

Direct methods:


TLDs, Films, MOSFETs,
and Diodes
Indirect methods:

DAP, Monte Carlo
Simulations, Mathematical
(experimental) formulae
Material
TLD - LiF





Small size – Easy placement
Tissue equivalence
Dose rate & angular dependence
Dose & Energy Dependence
No temperature & pressure correction
needed
Dose response
20
Saturation
dose
15
Relative
TL-light
output 10
Up to 1 Gy
for “LiF”
~ 1000 Gy
for “LiF”
Superlinear
region
5
Linear
region
0
1
10
100
Dose [Gy]
1000
Energy response
Relative
response
TLD Dose Calculation
D = (R-B) * C * kE* kF * kD
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R – TLD reader output signal
B – Background signal
C – TLD system calibration factor
kE – energy correction factor
kD – dose response correction factor
kF – correction factor for fading
TLD Calibration Procedure



Photon energies between 50 – 110 kV
Individual calibration for each radiation
machine
Calibration for entrance dose v.s. calibrated
ion-chamber
Determination of calibration factor according
to the procedure for each TLD used
TLD Calibration Procedure
Effective Dose & Risk Estimation
E  Wt.Ht
NRPB-SR279
ICRP 103
Radiological Procedures



Micturating Cystourethrography (MCU)
Hysterosalpingography (HSG)
Angiography



Lower limbs
Renal arteries
Carotid arteries
More procedures have been measured…
Micturating Cystourethrography (MCU)



The MCU is considered to be the gold
standard method used to detect and
grade vesicoureteric reflux
Represents the 30-50% of all
fluoroscopic examinations in children.
Children have a risk probability 2 to 3
times more than that of all adults of 50
years age
Patient and Co-patient Dosimetry



TLDs were placed in a thin plastic foil Each one contains 4 TLDs.
TLD placed on : Patient Skin at the ESD, testes, Ovaries and
Thyroid
At the left shoulder level of the Co-patient
Organ dose estimation



52 patients included in this
study
Organ
dose
estimated
using computer software
(CHILDOSE) provided by
the NRPB-SR279).
The
doses
are
also
normalised to unit ESD
(mGy) and unit DAP
(Gy.cm2).
Thyroid
Ovaries
Ovaries
Center Field
Testicle
MCU Results (mGy)
Patient
criteria
All patients
Positive
Negative
ESD
mean±SD
(range)
Thyroid
mean±SD
(range)
Testes/ovaries
mean±SD
(range)
co-patient
mean±SD
(range)
52
1.134±0.56
(0.372-2.36)
0.153±0.101
(0.021-0.53)
0.364±0.39
(0.052-1.78)
0.144±0.09
(0.034-0.5)
11
1.49±0.54
(0.954-2.04)
0.184±0.15
(0.044-0.348)
0.638±0.53
(0.113-1.162)
0.11± 0.09
(0.0350.221)
41
1.08±0.57
(0.372-2.363)
0.144±0.10
(0.021-0.534)
0.49±0.40
(0.052-1.78)
0.149±0.10
(0.034-0.5)
n
DRL = 1.7mGy
MCU Results
Risk estimation and the probability of fatal cancer and
hereditary effects are 107 people per mSv.
Organ
Effective dose
(mSv)
Risk of
malignancy*
107/Sv
Genetic effect
107/Sv
Thyroid
0.008
0.0064
-
Ovaries
0.084
0.84
8.4
Testes
0.073
0.73
7.3
MCU Results
Mean ESD (mGy) per examination in various studies.
Age group
Author
Newborn
Present study
1.15±0.5
Chapple et al
1 year
old
-
2 year
old
1.05±0.5
>5 years
old
-
7.63
-
11.56
Fotakis et al
3.49
4.49
-
5.76
Mantovani &
Giroletti
-
2.21
-
5.82
Hysterosalpingography (HSG)
37 women – Mean age 34 years old
Fluoroscopy and radiography
Tyroid
5 points of ESD measurement
(4TLDs/pack)
Center Field
Staff dose measurement
Central line
Symphysis pubisiliac spine
Central line
Symphysis pubisiliac spine
Symphysis
Pubis
HSG Results
Entrance Dose - ESD (mGy)
Group
No
Min
Median
Mean
DRL
Max
Thyroid ESD
Mean
(range)
Total
37
0,7
3,40
3,60
4,94
8,17
0,17
(0,06-0,51)
0,18
(0,04-0,46)
A
23
0,7
3,16
3,30
3,40
6,98
0,19
(0,06-0,51)
0,21
(0,05-0,46)
B
14
1,11
4,01
3,90
5,48
8,17
0,14
(0,06-0,14)
0,14
(0,04-0,25)
Staff
Dose
HSG Results
HSG Results
Organs
Eq. Dose
(mSv)
Probability
Carcinogenesis
x10-6
Ovaries
0,91
1,46
Uterus
1,28
0,81
Bone marrow
0,14
0,31
Bladder
1,22
4,76
Breast
0,04
0,46
Thyroid
0,03
0,06
HSG Results
Authors
No pat
Fruoro Time
(second)
No
radiographs
ESD
(mGy)
Ovaries Dose
(mGy)
Eff. Dose
(mSv)
This Study
37
18,2
(6-36)
0,2
(0-1)
3,60
(0,7-8,17)
0,91
0,43
Perisinakis
et al.
78
20
3,2
9,7±4,2
2,7
1,2
Calicchia
et al.
37
13
(6-30)
6.5
(6-7)
25,2±3,8
4,66
1,95
Gregan
et al.
21
15
(5-45)
2
(2-4)
14,6
(1,4-45,7)
3,4
Khouri
et al.
25
-
4-15
12,6
(4,99-36,6)
2,94
-
-
Angiographies
Dynamic
Procedures
Lower limbs
Renal
arteries
Carotid
arteries
Angiographies
Staff doses
ΕEff = 0,02 mSv /examination
Eye Lens
Thyroid
Lung
Dose (μSv)
Lower Limbs Renal Arteries
Angioo
Angio
14,9
14,1
0,75
0,7
1,7
Carotid
Arteries
15
0,75
1,8
Angiographies
6 areas of
measurement
4 areas of
measurement
10 areas of
measurement
Angiography of
Renal Arteries
Lower Limbs
Angiography
Angiography of
Carotid Arteries
(30 patients)
(21 patients)
(27 patients)
Angiography of lower limbs
Results
ESD
(mGy)
Abdomen
Pelvis
Thigh
Knees
Heels
Mean ESD/image
70,8
21,1-207,4
96,0
67,7
13,5-188,5
96,4
24,3
5,8-40,7
32,7
18,4
3,4-59,0
23,1
9,7
0,3-31,7
12,3
2,1
Author
Time (sec)
No images
Author
Eff. Dose (mSv)
This Study
96
103,7
This Stdy
9,8
Bor et al.
60
-
D Bor et al.
2,8-10,95
Bor et al.
60-282
59-165
Castellano IA et al.
3,1
McParland et al.
432
450
-
Hoskins PR et al.
2,8-9
B J McParland et al.
8,3
Mini et al.
144
114
H. M. Olerud et al.
6,4
Ruiz Cruce et al..
222
37
R Ruiz Cruces et al.
6,2
Struelens et al.
-
28-98
L. Struelens et al.
3,9-16,8
Thwaites et al.
145
29,9
J H Thwaites et al.
4
Wall et al.
126
-
J. Zoetelief et al.
7,2
Angiography of renal arteries
Results
Author
Fluoro Time
(min)
No radiographic
images
Sample
This Study
1,5
71,5
21
Bor et al.
3,0 - 5,2
28-190
6
Mini et al.
2,8
88
17
McParland
5,1
-
6
Goni et al.
3,9
-
63
Livingstone et
al.
2,42-9,79
196-303
109
Padovani
6,3
-
-
Angiography of renal arteries
Results
Eff. Dose
(mSv)
Mean
Range
Median
Std Dev
DRL
15,9
5,3-32,6
16,3
8,2
22,3
Authos
Eff. Dose
(mSv)
This Study
15,9
D Bor et al.
8,95-13,7
B J McParland
6,4
H. M. Olerud et al
11,9
Mini et al.
25
R S Livingstone et al
2,3 - 30,5
G J Kemerink
2,3-7,1
Angiography of carotid arteries
Results
Fluoro Time
(min)
No radiographic
Images
Sample
This Study
11
155,5
27
Bor et al.
5
83
19
Bor et al.
2,3-16,6
36-831
35
Mini et al.
7,8
199
12
McParland
10,3
-
11
Goni et al.
6,1
-
19
Bor et al.
3,3
122,6
5
1,1-3,4
-
17
11,3
-
35
Author
Struelens et al.
Fletcher
Angiography of carotid arteries
Results
Mean
Range
Median
Std. Dev.
DRL
8,9
0,9-21,9
7,0
6,3
13,88
Eff. Dose (mSv)
Authors
Eff. Dose (mSv)
This Study
8,9
D Bor et al.
2,5-4,9
Bor et al.
4,28-18,75
B J McParland
4,9
Olerud H M et al.
9,77
D Bor et al.
11,1
Conclusions

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Formation of a consistent dosimetric protocol for
TLD dose measurement in diagnostic radiology
Determination of DRLs in ALL radiological
procedures is necessary for better radiation
protection
Optimization of static and dynamic radiological
procedures based on absorbed dose to different
sensitive organs
Dose optimization to medical staff present to
interventional examinations
THANK YOU .