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RADIATION SAFETY
IN THE PRACTICE
OF CARDIOLOGY

what all women should know

ACKNOWLEDGEMENTS

Women as One would like to recognize the contributions from Sheila Sahni MD, FACC, FSCAI,
Alaide Chieffo, MD, FESC and Stephen Balter PhD, FAAPM, FACMP, FACR, FSCAI, FSIR for their work on “Radiation Safety in the Practice of Cardiology”

Sheila Sahni, MD, FACC, FSCAI

Sahni Heart Center, Hackensack-Meridian Health, Clark, NJ USA

Alaide Chieffo, MD, FESC

San Raffaele Hospital, Milan, Italy

Stephen Balter, PhD, FAAPM, FACMP, FACR, FSCAI, FSIR

Columbia University, New York, NY, USA

ENDORSEMENTS

Women as One would like to recognize our global partners for their endorsements.

Together, we can amplify our voices to create meaningful change to support women around the world.

OVERVIEW

WHAT THE PREGNANT CARDIOLOGIST NEEDS TO KNOW

(CONSIDERATIONS/GAPS)

RADIATION BASICS AND PROTECTION

RECOMMENDATIONS

CHANGES IN PROFESSIONAL LIVES OF CARDIOLOGISTS OVER TWO DECADES

Click on a category to view the graph and statistics.

  • Men
  • Women

LITTLE / NO CHANGE

  • Career satisfaction remains high
  • Women are more likely to:
    • Experience discrimination
    • Require paid/unpaid childcare help

LITTLE / NO CHANGE OVER TWO DECADES

SIGNIFICANT CHANGE

  • Aging workforce
  • Practice setting
  • Men now balancing career and family; less likely to travel professionally

LITTLE / NO CHANGE OVER TWO DECADES

CAREER SATISFACTION

graph

EXPERIENCE DISCRIMINATION

graph

REQUIRE CHILDCARE HELP

graph
  • 1996
  • 2006
  • 2015

50 YEARS AGE AND OLDER

graph

PRIVATE PRACTICE

graph

FAMILY REPONSIBILITIES IMPEDE PROFESSIONAL TRAVEL

graph
  • 1996
  • 2006
  • 2015

Lewis, S.J. et al. J Am Coll Cardiol. 2017;69(4):452-62.
Areas for which there has been minimal or no change in responses to survey questions regarding personal and professional life issues are contrasted with areas where significant changes have occurred.

AVOIDED PREGNANCY DURING OCCUPATIONAL RADIATION EXPOSURE

  • Yes
  • No

CARDIOLOGISTS UNDER 50

CARDIOLOGISTS OVER 50

Sarma A, et al JACC 2017;69:92

FAMILY PLANNING CONSIDERATIONS OF CARDIOLOGISTS

PRECONCEPTION

PREGNANCY

EARLY PARENTHOOD

Women are often asked whether they intend to have children during interviews

A career in cardiology often impacts family planning

Female cardiologists avoid pregnancy during periods of radiation exposure

Women underutilize radiation reduction and monitoring strategies

Cardiologist experience a high incidence of pregnancy complications

Pressure to take shorter parental leave

Women do not meet their breastfeeding goals

Avoid such questions

Offer all candidates information on parental leave policies

Recognize the importance of pregnancy, parental leave, and breastfeeding

Include radiation exposure recommendations in fluoroscopy training

Connect cardiologists with radiation safety officer

Provide maternity lead and fetal dosimeters

Parental leave of 2 months for all cardiologists (men and women) with flexibility to account for potential complications

Optimize space, me, and culture acceptance for women to express milk in the workplace

Sarma, A.A. et al. J Am Coll Cardiol. 2017;69(1):92-101.

PERCEIVED CHALLENGES AND FAMILY PLANNING CONSIDERATIONS OF CARDIOLOGISTS

  • When asked why cardiologists did not pursue interventional cardiology, women more commonly cited concerns regarding radiation exposure as compared with men (20% vs. 12%; p < 0.001).
  • When compared with women older than 40 years of age, women < 40 years of age were twice as likely to report radiation exposure as a barrier to choosing interventional cardiology (12% vs. 27%)
  • Women were relatively uninformed about whether their department had an official policy regarding radiation exposure during pregnancy
    • Only, 34% reported that their department did
    • 34% reported being unaware if their department had such a policy
    • 32% reported that their department did not
  • There was no difference between those older than 50 years of age versus younger than 50 years of age with respect to knowledge regarding such policies (p = 0.96), potentially limiting senior cardiologists from providing mentorship on this issue to younger colleagues.

RADIATION SAFETY KNOWLEDGE FOR OPTIMAL CAREER AND FAMILY PLANNING IS LACKING

  • Studies have shown a lack of knowledge for radiation safety and lack of routine implementations of radiation protective strategies
  • WIC Pregnancy Workforce Group suggested all cardiologists receive education regarding pregnancy radiation exposure on entering fellowship, at time of employment, and each time they undergo fluoroscopy credentialing

Y. Morishima, K. Chida, Y. Katahira, et al. Need for radiation safety education for interventional cardiology staff. Acta Cardiol, 71 (2016): 151-155
G. Sadigh, et al. Radiation safety knowledge and perceptions among residents. Acad Radiol, 21 (2014): 869-878

THE PREGNANT
CARDIOLOGIST

  • Review of available data and guidance from multidisciplinary societies on radiation safety
  • Review of regulatory requirements in the US and Europe

INTERVENTIONAL ROUNDS

  • SCAI Consensus Document on Occupational Radiation Exposure to the Pregnant Cardiologist and Technical Personnel
  • Describes the risk of radiation exposure to pregnant physicians
  • Educates on radiation monitoring and mechanisms to reduce radiation exposure
  • Clarifies the data – that to date, there is no data to suggest a significant increased risk to the fetus of pregnant women
  • Purpose was to also help justify that pregnant physicians should not be precluded from performing procedures in cath lab

Catheterization and Cardiovascular Interventions 77:232–241 (2011)

Occupational Radiation Protection of Pregnant or Potentially Pregnant Workers

  • IR: A Joint Guideline of the Society of Interventional Radiology (SIR) and the Cardiovascular and Interventional Radiological Society of Europe (CIRSE)
  • Joint guideline from SIR and CIRSE experts in both academic and private sectors of medicine
  • Acknowledges that pregnant radiation workers may have heightened concern of radiation risk to unborn child
  • Addresses misinformation surrounding reproductive and developmental risks of radiation exposure and its effect on the conceptus
  • Emphasizes that understanding of radiation doses and associated risks is necessary for both protection of conceptus as well as preventing potential discrimination and unnecessary constraints on pregnant women

Dauer, L.T et al. J Vasc Interv Radiol 2015; 26:171–181

Recommendations for Occupational Exposure

  • National Council for Radiation Protection (NRCP) and International Commission on Radiological Protection (ICRP)
  • Recommendations by the NRCP and ICRP for optimizing occupational exposure are controlled by the following:
    • Limit on the annual effective dose
    • Limit on the annual equivalent dose to specific organs or structures
    • Limit of annual equivalent fetal dose over the entire gestation
  • These recommendation are enforced by regulatory agencies
  • Europe: limits for occupational exposure are included the European Directive 2013/59/Euratom
  • In the US, implementation can vary from state to state

Dauer, L.T et al. J Vasc Interv Radiol 2015; 26:171–181

Occupational Exposure Limits for Pregnant Workers

NCRP
Monthly equivalent dose limit of 0.5mSv to the embryo/fetus (excluding medical natural background radiation) once pregnancy is declared
NRC (Nuclear Regulatory Commission)
Regulatory limit of 5mSv during the entire pregnancy of the declared pregnant woman
IRCP & European Commission
Equivalent dose to unborn child should be as low as reasonably achievable and not exceed 1mSv during duration of pregnancy

Bhatt, D. et al. Cardiovascular Intervention: A Companion to Braunwald’s Heart Disease; 2015

Risks in Pregnant Women Not Exposed to Medical Radiation

Spontaneous abortion
> 14%
Genetic abnormalities
4-10%
Intrauterine growth retardation
4%
Major congenital malformation
2-4%

Dauer, L.T et al. J Vasc Interv Radiol 2015; 26:171–181

FEtal Risk as a Function of Radiation Dose

Fetal risk as a function of radiation dose

Dose to conceptus (mGy) above natural background
Probability of no malformation
Probability of no cancer (0-19 years)
0
97
99.7
1
97
99.7
5
97
99.7

RECALL: US NRC Regulatory equivalent dose limit is 5mSv during the entire pregnancy of the declared pregnant woman

10
97
99.6
50
97
99.4
100
97
99.1
> 100
possible,
see text
higher

There is no evidence that radiation dose to the fetus < 100mGy during pregnancy is associated with an increased incidence of congenital malformation, stillbirth, miscarriage, growth malformation or mental disability

No statistically significant or convincing evidence of an increased risk of cancer in offspring of female radiation workers

Dauer, L.T et al. J Vasc Interv Radiol 2015; 26:171–181

2018 Occupational Fetal Dose Averages

FETAL: Cleveland clinic - 2018

Occupational Fetal Dose Average

  • All X-ray Departments
  • Cardiac EP Department Only
  • Maximum Fetal Dose (right Axis)
  • Regulatory Fetal Dose Limit = 5,000 (uSv)

Dauer, L.T et al. J Vasc Interv Radiol 2015; 26:171–181

2018 PHYSICIAN Occupational RADIATION DOSES

Cleveland clinic - 2018

  • Average Annual EDE
  • Maximum Annual EDE

Dauer, L.T et al. J Vasc Interv Radiol 2015; 26:171–181

CIRCLE CHART EXPRESSING DOSE LIMITS

3 mSv:

Annual natural background radiation dose in US

~0.3 mSv:

Under-lead dose to working pregnant interventionalist over entire gestation

~0.9 mSv:

How much fetus of working pregnant interventionalist estimated to receive over entire gestation

100 mSv:

Known threshold for fetal injury

* Please note, legal and natural dose limits are based on US data. Limits vary by country

Ghatan C and Kothary N. Radiation Safety Considerations for the Female Interventionist. Endovascular Today. August 2016

SAFE RADIATION DOSE FOR THE PREGNANT CARDIOLOGIST

  • Fetal radiation ≤ 50 mSv (5 rem) is considered negligible
  • This dose does not affect the outcome of the pregnancy compared to control populations exposed to background radiation estimated as < 1 mGy (0.1 rad) over the gestational period

Brent RL. Clin Perinatol 1986;13:615-48
Catheterization and Cardiovascular Interventions 77:232–241 (2011)

HOW THE PREGNANT CARDIOLOGIST SHOULD MANAGE RADIATION EXPOSURE

  • Dosimeter – wear additional badge under your lead apron at the waist level
    • Keep track of multiple sites/locations
  • Pregnancy should be declared to the radiation safety office to ensure protection of fetus
    • Confidential disclosure
  • US Federal law prohibits against discrimination of pregnant workers
  • Practice ALARA!
  • Decrease occupational exposure through radiation protection measures

Brent RL. Clin Perinatol 1986;13:615-48
Catheterization and Cardiovascular Interventions 77:232–241 (2011)

Managing Occupational Exposure

  • Understand basic radiation physics
  • Understand lead garments and protective wear
  • Understand positional orientation of oneself and equipment

RADIATION
SAFETY

best practices

PATIENT-CENTERED VIEW

X-RAY SYSTEM

THREE MAJOR COMPONENTS
X-RAY TUBE
PATIENT
DETECTOR ASSEMBLY
Hirshfeld et al. 2018 ACC/HRS/NASCI/SCAI/SCCT Expert Consensus Document on Optimal Use of Ionizing Radiation in CV Imaging.
J Am Coll Cardiol. 2018 Jun 19;71(24):2811-2828.

PROVIDER-CENTERED VIEW

X-RAY SYSTEM

THREE MAJOR COMPONENTS
X-RAY TUBE
PATIENT
DETECTOR ASSEMBLY

RADIATION EXPOSURE CONCEPTS

QUANTITY
MEDIUM
MEASUREMENT
UNIT
Air Kerma
Air
X-tube output
Milligray (mGy)
Absorbed dose
Tissue
Tissue dose
Milligrays (mGy)
Equivalent dose
Tissue
Absorbed dose x radiation weighting factor
Millisieverts (mSv)
Effective dose
Human
Whole body effective
Millisieverts (mSv)

1 rem = 10 mSv
Y. Morishima, K. Chida, Y. Katahira, et al. Need for radia on safety educa on for interven onal cardiology sta . Acta Cardiol, 71 (2016): 151-155
G. Sadigh, et al. Radia on safety knowledge and percep ons among residents. Acad Radiol, 21 (2014): 869-878

PATIENT RADIATION DOSE RANGES FOR CARDIAC PROCEDURES

MODALITY
PROTOCOL
TYPICAL EFFECTIVE DOES (mSv)
Fluoroscopy
TAVR, transapical approach
12-23
Fluoroscopy
TAVR, transfemoral approach
33-100
Fluoroscopy
Diagnostic electrophysiological study
0.1-3.2
Fluoroscopy
Radiofrequency ablation of arrhythmia
1-25
Fluoroscopy
Permanent pacemaker implantation
0.2-8
Fluoroscopy
Diagnostic invasive coronary angiography
2-20
Fluoroscopy
Percutaneous coronary intervention
5-57
Hirshfeld et al. 2018 ACC/HRS/NASCI/SCAI/SCCT Expert Consensus Document on Optimal Use of Ionizing Radiation in CV Imaging.
J Am Coll Cardiol. 2018 Jun 19;71(24):2811-2828.

PATIENT RADIATION DOSE RANGES FOR CARDIAC PROCEDURES

Click on a category to view the results

MODALITY
PROTOCOL
TYPICAL EFFECTIVE DOES (mSv)
MDCT
Coronary CT angiography;
helical, no tube current modulation
8-30
Coronary CT angiography;
helical, tube current modulation
6-20
Coronary CT angiography;
prospectively triggered axial
0.5-7
Coronary CT angiography;
high-pitch helical
<0.5-3
CT angiography, pre-TAVR:
coronary (multiphase) and chest/abdomen/pelvis
5-50
Calcium score
1-5
Attenuation correction
<0.5-2.0
EBCT
Calcium Score
1
SPECT
10 mCi 99mTc sestamibi rest/
30 mCi 99mTc sestamibi stress
11
10 mCi 99mTc sestamibi rest/
30 mCi 99mTc sestamibi stress
17
30 mCi 99mTc sestamibi rest/
30 mCi 99mTc sestamibi stress
18
10 mCi 99mTc sestamibi stress only
2.7
30 mCi 99mTc sestamibi stress only
8
Hirshfeld et al. 2018 ACC/HRS/NASCI/SCAI/SCCT Expert Consensus Document on Optimal Use of Ionizing Radiation in CV Imaging.
J Am Coll Cardiol. 2018 Jun 19;71(24):2811-2828.

3 FUNDAMENTALS OF RADIATION SAFETY

Time

SPEND LESS TIME ON THE PEDAL

Distance

INCREASE THE DISTANCE FROM X-RAY SOURCE

Shielding

BLOCK SCATTERED RADIATION FROM THE PATIENT

Hirshfeld et al. 2018 ACC/HRS/NASCI/SCAI/SCCT Expert Consensus Document on Optimal Use of Ionizing Radiation in CV Imaging.
J Am Coll Cardiol. 2018 Jun 19;71(24):2811-2828.

PROTECTIVE MEASURES FOR INTERVENTIONAL SUITE

INTERVENTIONAL OUTFIT WITH ACCESSORIES

TABLE SET-UP

IMAGE ACQUISITION

BADGE MONITORING

Hirshfeld et al. 2018 ACC/HRS/NASCI/SCAI/SCCT Expert Consensus Document on Optimal Use of Ionizing Radiation in CV Imaging. J Am Coll Cardiol. 2018 Jun 19;71(24):2811-2828.

INTERVENTIONAL OUTFIT

Leaded glasses

Shoulder Pads

Leaded apron

Radiation badge

Lead thyroid collar

Ring Dosimeter

Leg shields

Personal Rules for
my lead
MAKE SURE YOUR LEAD FITS
INVEST IN YOUR COMFORT
HANG UP YOUR LEAD
DON’T SIT IN YOUR LEAD

LEAD APRON THICKNESS

  • 0.5-mm thickness attenuates 98- 99.5% of the scatter radiation dose
  • 0.35-mm thickness attenuates approximately 95-96% of the scatter of radiation
  • Handle lead with care – protection is lost when they crack!
  • Monitor deterioration and improper storage
  • Aprons should undergo periodic screening for monitoring of defect

Cathet Cardiovasc Diagn 1992;25(3):186-94.

Pregnant Women and Lead Apron Thickness

  • Historically, women were told to wear “double” lead or 0.5mm lead only throughout the duration of their pregnancy
  • Data shown thus far confirms that the majority of fetal dose exposure rarely exceeds 0.3mSv

Pregnant Women and Lead Apron Thickness

SPINE PROBLEMS VS INVASIVE YEARS

  • % in Sample
  • % with Spine Problems

orthopedic problems AND
total annual case load

  • Spine Problems
  • Hip, Knee or
    Ankle Problem

RADIATION EYE PROTECTION

  • Use of 0.75mm lead equivalent glasses can decrease dose by factor of 5-10
  • Use of scatter-shield can decrease the lens dose by a factor of 5-25
  • Use of both glasses and scatter-shield can decrease lens dose by factor of 25 or more
  • Cataract development is a deterministic effect such that there is threshold dose below which it won't develop.
  • Threshold for radiation induced lens injury (opacities and cataracts) of 1 to 2 Gy for a single acute exposure
  • The minimum latent period between exposure and diagnosis is ~ 1 year.

Heart 2003;89(10):1123-4.

TABLE POSITION

Drag to move the patient to view the radiation exposure results.

OPTIMAL

TABLE TOO LOW

TABLE TOO LOW / DETECTOR TOO HIGH

TRANSPARENT LEAD SHIELDS

  • Significantly reduces radiation exposure to the operator’s eyes but not the hands
  • Lead shields ( ~1mm) can attenuate at least 99% of the scatter radiation and in studies reduced overall radiation exposure by 50-75%
Am J Cardiol 2002;89(1):44-49.

LEAD APRON CAP

  • 0.5mm lead equivalent cap provides additional protection from scatter radiation compared with lead shielding alone
  • LAO projections create high level scatter radiation to operator’s left side
  • Occupational radiation exposure-induced malignancies with left side involvement have been speculated by a number of observational studies
  • Anecdotal reports of additional weight causing headaches
Fetterly KA et al. J Radiol Prot. 2017 Mar 20;37(1):43-58
Roguin, A et al. Am J Cardiol. 2013 May 1;111(9):1368-72

PUTTING IT ALL TOGETHER

DISTANCE FROM THE IMAGE INTENSIFIER

gradient graph doctor numbers
  • Increasing the working distance from 40 cm to 80cm can decrease scatter radiation to around one fourth of the original dose.
  • Use additional tubing in radial cases to increase working distance away from radiation sources

Slide courtesy of Dr. Patricia Best

AVOID STEEP ANGULATIONS OF C-ARM

Bhatt, D. et al. Cardiovascular Intervention: A Companion to Braunwald’s Heart Disease; 2015

IMAGE ACQUISITION

  • Views that minimize radiation exposure:
    AP views and RAO views should be preferred to the LAO views to reduce radiation dose.
  • Frame rate:
    Halving the frame rate reduces the radiation dose by 50%.
  • Use collimation:
    Active collimation reduces volume irradiate, reducing overall patient dose and scatter radiation.

Br J Radiol 1996;69:860-4.
Slide courtesy of Dr. Patricia Best

RADIATION EXPOSURE REDUCTION RULES

1
ALARA
2
Decrease number and length of cine acquisitions and fluoro time
3
“Table UP, I. I. DOWN”Decrease patient to Image intensifier distance + Increase source to image distance
4
Minimize steep C-arm angulation
5
Vary the C-arm angles to avoid repetitive exposure
6
Limit digital magnification (increase skin dose exposure by 50%)
7
Apply Collimation as often as possible
J Am Coll Cardiol Intv 2012;5:866 –73

IMPLEMENTING A CULTURE OF RADIATION SAFETY

does it work?

STATISTICAL SUMMARY OF PATIENT VARIABLES, PROCEDURAL PARAMETERS, AND CUMULATIVE SKIN DOSE FOR THE FIRST & LAST QUARTERS OF THE 3-YEAR STUDY PERIOD

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