Dosimetry in angiography and interventional radiology

Angela Karambatsakidou, Enheten för Röntgen och IJ-Strålning, VO Sjukhusfysik

Philips image gallery Siemens image gallery

Dosimetry in angiography and interventional radiology

Angiography and Interventional radiology, 2014

General information about interventional radiology

Dosimetry in interventional radiology

Special topic: Paediatric interventional cardiology

Agenda

Interventional

Radiology

CT

Radiography


IAEA Training Material on Radiation Protection in

Diagnostic and Interventional Radiology

Dose levels


Pioneer in interventional cardiology: Andreas Gruntzig, Zurich

2000st lyckade ballongdilatationer

Gick bort 5 mån innan introduktionen av det 1:a coronara stentet

Interventional era started in 1977

37-årig man


Angiography and Interventional radiology


Philips image gallery

Angiography and Interventional radiology


DSA quantification (Siemens image gallery)

Stenosis of the right carotis communis.

3-D RA quantification (Siemens image gallery)

Basilar aneurysm of the top end of the basilar artery.

DynaCT (Siemens image gallery) AVM

embolization 3D roadmap (Philips image gallery)

Real-time image guidance for catheter navigation.

Different interventional techniques with clinical images


Interventional cardiology

PTCA

Case: bifurcation lesion

AP, 38 CR

LAD-D1

LAO 50, 38 CR

D1

IAEA



Case 1 bifurcation lesion

A

stent and balloon inflation

B

balloon angioplasty (PTCA)technique

PTCA & stentingtechnique

IAEA


CANCER

STOCHASTIC EFFECTS

DETERMINISTIC EFFECTS

LENS INJURIES

SKIN INJURIES

HEREDITARY DISORDERS IN THE DESCENDANTS

IAEA Training Material on Radiation Protection in

Diagnostic and Interventional Radiology

Radiation effects on humans


Risks in angiography and interventional procedures

Erythema

(>2 Gy, 1-10 d)

Depilation

(>3 Gy, 3 wk)

Dry desquamation

(>14 Gy, 4 wk)

Moist desquamation

(>18 Gy, 4 wk) Dermal necrosis

(>12 Gy?, >1 yr)

Cataract

(>1-2 Gy, >5 år) 0.5 Gy


Symptoms usually delayed by 1-3 weeks Patients often unaware of symptoms of injury associated

with radiation delivery Experience show a lack of association between lesion and

previous cardiologic procedure

IAEA: Radiation Protection in Cardiology, Lecture 1

Experiences with skin injures in interventional cardiology


Electrophysiological and ablation procedure

8 days after the third procedure

3 procedures in 4 months, each with more than 100 minutes of fluoroscopy

Vlietstra RE et al. J Interv Cardiol. 2004 Jun;17(3):131-42


Prolonged-, Multiple Procedures and Beam-overlapping


Schueler et al. Radiographics 2006;26:1533-41

Large patients



”Dose rate” = Incident air kerma rate

22 cm 30 cm

(>2 Gy, 1-10 d)


Steep beam angulations (arms and/or breast are in the radiation beam)


0 0,5 1 1,5 2 2,5

Low

Normal

High

Cine

Rel. Dose

Do

se

le

ve

l

0 0,5 1 1,5 2

14

17

23

Rel. Dose

FO

V (

cm

)

The Essential Physics of Medical Imaging, figure 9-8



0 mm Cu 0,5 mm Cu

Schueler et al. Radiographics 2006;26:1533-41


Tube filtering



Collimation

Date of download:

2/7/2014

Copyright © The American College of Cardiology.

All rights reserved.

Cine Fluoroscopic Images in the Lateral Projection in a 6.5-Year-Old

Female Child With a PDA

(A) Angiogram in the descending aorta demonstrating a 2-mm patent

ductus arteriosus (PDA) at its narrowest diameter (arrow),

angiographic type A.

J Am Coll Cardiol Intv. 2008;1(6):603-611. doi:10.1016/j.jcin.2008.07.007

Collimation with 1 cm

REID ~25%

Skin Dose ~ Same REID

Operator experience



3

4

5

6

mS

v/G

ycm

2

median: 4.1

median: 3.4

Operator A Operator B

Coronary angiography (adults)

Karambatsakidou et al. Br J Radiol. 2005 Sep;78(933):803-9


Geijer et al Eur. Radiol. 12 (2002)

Calculated

effective

dose rate

KAP rate

Operator

dose rate

Combined Actions

Relative

dose rate

Dose Reduction

+ angulation Start + filtration +collimation

LAO caud PA 2 cm


PTW

Dosimetric parameter for risk estimation

Kerma-Area Product (KAP)


May over- or underestimate skin dose depending on:

how well IRP coincides with the skin surface

backscattered factor (BSF)

radiation geometry

Dosimetric parameter for risk estimation

Reference dose


•Image acquisition

•Fluorography

•Exposure

•Cineradiography

•Stationary acquisition

Fluoroscopy

Dose Report


Fluoroscopy Time

Chida Koichi, AJR 2006; 186:774–778

Graph shows correlation between maximum skin dose and fluoroscopic time in percutaneous coronary intervention (r = 0.628, p < 0.0001).

Dose Report

Measures Time, Not Dose!

Correlates Poorly With Maximum Skin Dose!

http://www.ajronline.org/content/186/3/774/F4.large.jpg


Kerma-Area Product (KAP)

Miller, D.L, J Vasc Interv Radiol 2003;14:977-990

Figure Graph shows correlation between maximum skin dose (MESD) and kerma-area product (KAP) for 709 procedures (r = 0.848, p < 0.000001).

Dose Report

Good Correlation With Maximum Skin Dose

Tool For Cancer Risk And

Skin Dose Estimations

MESD (Gy)

KAP (Gycm2)


Reference Dose

Figure Graph shows correlation between maximum skin dose (MESD) and reference dose for 709 procedures (r = 0.862, p < 0.000001).

Miller, D.L, J Vasc Interv Radiol 2003;14:977-990

Dose Report

Good Correlation With Maximum Skin Dose

Poor Estimate Of Stochastic Risk

MESD (Gy)

Reference Dose (Gy)


Estimating Maximum Skin Dose (MESD)

Monte Carlo X-ray dose simulations (e.g., PCXMC)

Accurate dose estimations

Time consuming! Requires information for

almost all projections

28


Based on reference dose. Included in dose reports

Time consuming! Requires information for

almost all projections Omar A. et al.,SPIE MI 14: 9033-63 (2014)


Khodadadegan et al, J Digit Imaging. 2011 Aug;24(4):626-39


DICOM dose structured report (Dose SR)

Includes most parameters required for MESD

Ideally to use for automated monitoring of skin dose by an external program


Journal of the ICRU Vol 5 No 2 (2005) Report 74

Figure Three dimensional representation of the patient skin dose distribution (mGy) as measured with a grid of TLDs for a coronary angiography in a biplane setting.


Thermoluminescent dosimeter (TLD)

Accurate

A rectangular array of TLDs is required for high spatial resolution

Nearly tissue equivalent



Gafchromic film


Do not require film processing

Can be handled in normal light conditions

Do not obscure diagnostic information

Gives an accurate skin dose distribution at the level of the skin

Allows for accurate skin dose estimations


Paediatric interventional cardiology

Kosair Children´s Hospital Konstantinos & Leandros


Effective doses in paediatric interventional cardiology

Karambatsakidou et al. Br J Radiol. 2009 Aug;82(981):748-55.

0

10

20

30

40

50

60

70

80

0 50 100 150 200 250

DAP (Gycm2)

Eff

ecti

ve

Do

se (

mS

v)

15y 10y 5y 1y 0y

Linear (0y) Linear (1y) Linear (5y) Linear (10y) Linear (15y)

nyfödd 1 år

5 år

10 år

15 år

Age Mean E

0 13

1 8.6

5 6.4

10 8.6

15 12.7

10-20% ICRP 103

674 children who underwent cardiac catheterization due to congenital anomalies, between the years 1950-1970

Expected number of malignancies for all sites was 4.75, while the observed number was 11.0


Int J Epidemiol. 2000 Jun;29(3):424-8




Include children who undergone at least one angio/interv in the age of <10 years

Evaluate the risk of leukaemia and solid cancers

Radiation dose will be estimated retrospectively

At present time: 4500 children (2000-2011) are already been included in the cohort


”Linear No Threshold” - LNT-modellen

French Academy of Sciences (2004)

The American Nuclear Society (2001)

Ait-Ali (2010)

Beels (2009)

?

?


0,0

0,2

0,4

0,6

0,8

1,0

1,2

RE

IDo

rgan

/ RE

IDto

t

leukemi breast colon liver lung ovary stomach bladder other

Risk of radiation exposure-induced cancer death

Submitted in BJR


0 1 5 10 150.000

0.001

0.002

0.003

0.004

0.005

0.006

0.007

RE

IDo

rga

n/E

qu

ivale

nt

org

an

do

se (

%/m

Sv)

Age (years)

breast (F)

lung (F)

lung (M)

Relationship between risk, age and gender

0 1 5 10 150.000

0.005

0.010

0.015

0.020

0.025

0.030

0.035

RE

IDto

t/Eff

ecti

ve d

ose (

%/m

Sv)

Age (years)

Female

Male

Submitted in BJR


Relationship between risk, age and gender

0,0

0,1

0,2

0,3

0,4

0,5

0,6

0,7

0 1 5 10 15

RE

ID (

%)

Age (years)

Female

Male

Submitted in BJR


Factors affecting cancer risk

Patient population (age and gender)

Complexity of procedures

Machine settings and beam geometry

Choice of mortality cancer data

Choice of DDREF


Questions

Angela Karambatsakidou, Enheten för Röntgen och IJ-Strålning, VO Sjukhusfysik

Assessment of local high doses in clinic routine


Skin dose estimation

Action/Alarm levels

Patient follow-up

Statistics

Agenda

IAEA: Radiation Protection in Cardiology: Why talk about radiation protection in cardiology?

Deterministic effects


Gafchromic XR-RV3 configuration

Dose Range 0.05-15 Gy

Energy Range 20 kV-200 kV

Barium


Precautions in measuring skin dose with Gafchromic XR-RV3

Orientation of the film ~20% for the beam energies used in cardiology

and for a Kair~0,5 Gy.

Energy dependence for white facing the tube: 9%, 80-120kV, 5Gy

Energy dependence for yellow facing the tube: 7%, 80-120kV, 5Gy

Orientation of the film and beam quality

McCabe et al. Medical Physics, Vol. 38, No. 4, April 2011


Sensitometric response of GAFCHROMIC® film, type XR-

RV3 Comparator strip


± 25 %

Color Reference Chart or Flatbed Scanner

Red channel values



Time period between exposure and scan

Film darkness increase compared to 1h postexposure measurement

0

0,5

1

1,5

2

2,5

0 5 10 15 20 25 30 35

Dif

fere

nc

e in

fil

m r

es

po

ns

e (

%)

Postexposure time (h)

1 Gy

2 Gy

3,8 Gy

5,7 Gy

24±4 h




Contour plot without using a scanner

nonuniformity correction Contour plot with correction for nonuniformity in

scanner response

Nonuniformity correction



6

8

10

12

14

16

18

Operator B

mS

v/G

ycm

2

median: 9,4

Skin dose distribution in PCI

General action level 100 Gycm2 (KAP)? Or 5 Gy (cumulative air kerma)? Or 3 Gy (MESD)

Procedure dependent action level?

Operator dependent action level?


Determination of action/alarm levels


LARMNIVÅER

Kardiologiska angioverksamheten, Solna

Diagnostik : 350 Gycm2

Intervention: 150 Gycm2

Kombination: 200 Gycm2

Om DAP-värdet för en undersökning överskrider värdet ovan skall en kopia av

undersökningsrapporten skickas till:

Angela Karambatsakidou

Enheten för sjukhusfysik och IJ-strålning (H2:06)

VO Sjukhusfysik, Solna

Angiography and Interventional techniques, 2013

Cran

Dx Sin

Caud

Dosfördelning från en 1-sidig

panangiografisk röntgenundersökning

som inkluderar 2 st 3DRA. Den

maximala huddosen var 35 mGy och

var lokaliserad centralt på

bakhuvudet.

Large Cerebral Aneurysm


Larmnivån

DAPexp: 450 Gycm2

Skin doses in neuro angiography

Patient follow-up


Information about previous interventional procedures

Inform the patient about potential radiation risks

Cumulative skin dose ≥3Gy (≥1Gy for procedures

likely to be repeated):Records of exposure

(position and skin dose) should be kept.

Advice to patient after the procedure about

the radiation effects (symptoms, signs)

Cumulated skin dose ≥3Gy: Follow-up patient 10-14 days after exposure

and referral to a dermatologist if serious and chronic damage are seen.

Inform personal physician about the radiation effects and doses

Threshold values not exceeded


Previous interventional procedures ???

DAP, Date

Yes

Cumulative skin dose ≥3 Gy?

Yes

Wait 6 week for next angio/interv

Perform the angio/interv but avoid irradiation in regions with skin injury.

No

OK!

Perform angio/interv

No

OK!

Perform angio/interv

Before the examination


Cumulative skin dose ≥3 Gy?

Yes

Register DAP, exam type, date and contact Medical physicist for skin dose estimation.

Cumulative skin dose: 3-10 Gy

Inform patient to inspect the irradiated area for a potential skin injury 10-14 days after examination

Yes

Referral to dermatologist

Feedback to physicist, physician

No

Cumulative skin dose: ≥10 Gy?

Inform patient after the procedure about a probable radiation injury

Referral to dermatologist

Feedback to physicist, physician

No

Register DAP, exam type, date

After the examination


Patient information

>10 Gy

3-10 Gy


Skin doses > alarm levels in the clinic at Karolinska University Hospital, Solna (2009-2013)

Skin erythema: > 2 Sv

Temporary epilation: > 3 Sv

Skin necrosis (delayed): > 12 Sv

Skin dose (Sv) Number of patients

2 - 3 44

3 - 10 32

>10 1

Skin doses


Swedish Coronary Angiography and Angioplasty Register from 2013

Statistics from SCAAR

0

500

1000

1500

2000

2500

3000

1 2 3 4 5 6 7 8 9 10 11 12

Med

ian

DA

P (μ

Gym

2)

Operator

Coronary Angiography

10

16 172

84

13

20

33

7

98 35

50

81

0

1000

2000

3000

4000

5000

6000

7000

1 2 3 4 5 6 7 8 9 10 11 12

Med

ian

DA

P (μ

Gym

2)

Operator

Coronary Angiography + PCI

23

7

144 85

14

44

41 92

32

57

40 64


Statistics from SCAAR

Coronarangio

Me

dia

n D

AP

(μ

Gym

2)

1

1

1

1

1

1

1 Date for procedure

2013-01-01 – 2014-01-01

Me

dia

n D

AP

(μ

Gym

2)

Date for procedure

Coronarangio + PCI


Dose and Risk Advisor in Paediatric Interventional Radiology

y = 0,0272x

y = 0,065x

0,0

0,5

1,0

1,5

2,0

2,5

0 10 20 30 40

RE

ID (

%)

DAP (Gycm2)

Male

Female

Level of risk

(%)

Risk term

0.001-0.01 Very Low

0.01-0.1 Low

0.1-1 Moderate

>1 High

6 months – 2.5 years

UK Department of Health


Questions


Thank you

Documents

Dosimetry in angiography and interventional radiology