News | Radiation Dose Management | May 12, 2017

Study Reveals Low Adoption of IAEA Recommendations for Reduced Nuclear Cardiology Radiation Exposure

Majority of sites worldwide found to be using less than half of the suggested quality metrics to achieve dose of 9 mSv or less

Study Reveals Low Adoption of IAEA Recommendations for Reduced Nuclear Cardiology Radiation Exposure

May 12, 2017 — A study in 65 countries has revealed low adoption of International Atomic Energy Agency (IAEA) recommendations to reduce nuclear cardiology radiation exposure. The research was presented at ICNC 2017, May 7-9 in Vienna Austria, by Edward Hulten, M.D., a cardiologist at the Walter Reed National Military Medical Center, Bethesda, Md.

Nuclear cardiology uses small amounts of radioactive tracers that are injected into the veins and taken up by the heart. A gamma camera images the radiation from the tracer. The cardiac images are used to measure the heart size and function, identify coronary heart disease and predict the risk of a heart attack.

Hulten said, “Nuclear cardiology is a key part of contemporary cardiology management and around 15 to 20 million procedures are performed annually. It gives information regarding diagnosis, prognosis, and the effects of therapeutic interventions.”

“Concerns have been raised about tests, including nuclear cardiology, that expose patients to ionizing medical radiation,” he continued. “Medical radiation potentially raises the lifetime risk of cancer which is important for all patients, especially younger patients or when considering additional radiation over time from further medical studies.”

A goal of 9 mSv or less radiation exposure per scan was recommended by the American Society of Nuclear Cardiology (ASNC) in 2010. It was noted in a 2016 International Atomic Energy Agency (IAEA) nuclear cardiology guideline but not formally endorsed as a recommendation.

The IAEA developed eight quality metrics for responsible radiation use in nuclear cardiology:

  • Avoiding thallium 201 stress testing;
  • Avoiding dual isotope testing;
  • Avoiding too much technetium-99m and thallium 201;
  • Using stress-only imaging;
  • Use of camera technologies to reduce dose;
  • Use of weight-based dosing strategies for technetium-99m; and
  • Avoiding inappropriate dosing that can lead to “shine-through” artifacts.

The IAEA Nuclear Cardiology Protocols Study (INCAPS) assessed adherence to the eight quality metrics. The present analysis investigated which metrics were most helpful in meeting the ASNC’s 9 mSv target. During one week in 2013, 308 nuclear cardiology laboratories were studied in 65 countries in Africa, Asia, Europe, Latin America, North America and Oceania.

The survey included 7,911 nuclear cardiology scans. There was significant variability in adherence to the quality metrics across laboratories and regions. There was low adherence overall, with the majority of sites implementing less than half of the quality metrics.

When the researchers performed multivariable logistic regression analysis, they found that the practices most strongly associated with achieving a 9 mSv or less scan were the use of stress or rest only imaging, avoiding thallium, and use of camera technologies to reduce radiation dose.

Hulten said, “When the 9 mSv recommendation was made in 2010 it was suggested that it should be achieved in 50 percent of scans by 2014. The INCAPS survey shows that there is still work to do. It is possible to reduce radiation exposure with existing techniques. Cadmium zinc telluride (CZT) cameras are more sensitive and allow for reduced dose scanning. With certain tracers you can achieve 1 mSv or less. But some scans use more than 30 mSv, so there is huge variability.”

Not every site has all of the hardware and technology, said Hulten, so the first step is to look at what is possible within each lab. He said, “There are improvements every lab can make regardless of money – for example multiple position imaging, weight-based dosing and stress-only techniques. They do require adapting existing workflows which takes leadership but they should be feasible in most labs.”

He added, “Eventually cameras wear out and perhaps the decision on a replacement could factor in a reduced radiation dose which also lowers false positive tests and has the potential to reduce lab costs.”

Hulten concluded, “The INCAPS survey is a crucial step towards improving patient care in the field of nuclear cardiology by quantifying worldwide adherence to best practices. Any test involving ionising radiation will increase cancers within a population but the risk must be weighed against the benefit of gaining information about heart disease. The 9 mSv goal is achievable, and the lower the better.”

For more information: www.escardio.org

 

Read the article "Recent Advances in Cardiac Nuclear Imaging Technology." 

Watch the VIDEO "PET vs. SPECT in Nuclear Cardiology and Recent Advances in Technology." An interview with Prem Soman, M.D., director of nuclear cardiology at the Heart and Vascular Institute, University of Pittsburgh, and president-elect of the American Society of Nuclear Cardiology (ASNC), explained advances in PET and SPECT imaging. 

Watch the VIDEO "Trends in Nuclear Cardiology Imaging." A discussion with David Wolinsky, M.D., director of nuclear cardiology at Cleveland Clinic Florida and past-president of the American Society of Nuclear Cardiology (ASNC), discusses advancements in nuclear imaging and some of the issues facing the subspecialty. 

Related Content

Women’s Heart Attack Research Program (HARP) shows combining OCT and cardiac MRI can detect the underlying cause of heart attack in women who did not have blocked arteries

The Women’s Heart Attack Research Program (HARP) study shows combining OCT and cardiac MRI can help detect the underlying cause of heart attacks in women who did not have blocked arteries.

News | Cardiac Imaging | November 17, 2020
November 17, 2020 — Diagnostic imaging techniques were able to find the underlying cause of heart attack in many wome
An example of a CT coronary artery calcium scoring exam showing how each vessel segment is scored to assess a patient's risk for a future heart attack. Example is from Philips Healthcare.

An example of a CT coronary artery calcium scoring exam showing how each vessel segment is scored to assess a patient's risk for a future heart attack. Example is from Philips Healthcare.

News | Cardiac Imaging | September 25, 2020
September 25, 2020 — A study out of University Hospitals (UH) found that removing the cost barrier for coronary arter
Rafael Rivero, M.D., Global Head of Medical Affairs at MSI, said: "The importance of MyoStrain cannot be understated because of the test's immense clinical value and ability to quantify intramyocardial dysfunction across 48 segments of the heart. In a six-heartbeat MRI scan, MyoStrain arms physicians with novel clinical information about a patient's heart health."
News | Cardiac Imaging | August 11, 2020
August 11, 2020 — Myocardial Solutions, Inc. and United Imaging, Inc.
The Mindways Solid phantom with volume of interest in the quality assurance phantom (red circles, left side). A participant's noncontrast-enhanced axial CT (right side) with volume of interest (yellow circles) in the trabecular bone compartment of three vertebrae for bone mineral density measurements. Image courtesy of Radiological Society of North America

The Mindways Solid phantom with volume of interest in the quality assurance phantom (red circles, left side). A participant's noncontrast-enhanced axial CT (right side) with volume of interest (yellow circles) in the trabecular bone compartment of three vertebrae for bone mineral density measurements. Image courtesy of Radiological Society of North America

News | Cardiac Imaging | July 15, 2020
July 15, 2020 — ...
Cardiac MR can offer data above and beyond anatomical imaging, which is the main reason why this system was installed at Baylor Scott White Heart Hospital in Dallas. The system is a dedicated heart MRI scanner.

Cardiac MR can offer data above and beyond anatomical imaging, which is the main reason why this system was installed at Baylor Scott White Heart Hospital in Dallas. The system is a dedicated heart MRI scanner.

News | Cardiac Imaging | June 29, 2020
June 29, 2020 — A type of smart magnetic r...
New Multimodality Cardiac Imaging Guidelines for Competitive Athletes Created. ASE SCCT and SCMR recommendations for imaging, screening atheletes.
News | Cardiac Imaging | May 11, 2020
May 11, 2020 – Competitive athletes are a rapidly growing population worldwide.
Figure 4 for the study. Images of a 65-year-old man (patient 6). (a) Cardiac MRI perfusion shows perfusion deficit of anterior/anterolateral wall attributed to left anterior descending artery/left circumflex artery (*). (b) CT coronary angiography. (c) Coronary angiography, left anterior oblique projection with caudal angulation. (d) Three-dimensional image fusion helped refine diagnosis: perfusion deficits (*) were most likely caused by narrow first diagonal branch and its first, stented side branch (arrow

Figure 4 for the study. Images of a 65-year-old man (patient 6). (a) Cardiac MRI perfusion shows perfusion deficit of anterior/anterolateral wall attributed to left anterior descending artery/left circumflex artery (*). (b) CT coronary angiography. (c) Coronary angiography, left anterior oblique projection with caudal angulation. (d) Three-dimensional image fusion helped refine diagnosis: perfusion deficits (*) were most likely caused by narrow first diagonal branch and its first, stented side branch (arrowhead). Retrospectively, denoted lesion could also be found at CT coronary angiography and coronary angiography (arrowheads in b and c, respectively). CT FFR = CT-derived fractional flow reserve, LGE = late gadolinium enhancement. Image courtesy of RSNA, Radiology.

News | Cardiac Imaging | May 04, 2020
May 4, 2020 – A new technique that combines computed tomography (CT) and magnetic resonance imaging MRI can bolster c
An example of a coronary computed tomography angiography (CCTA) exam. The CIAO study looked at patients who have a problem of blood flow limitation and chest pain symptoms in the absence of a 50 percent or more artery narrowing, known as ischemia with no obstructive CAD, or INOCA.

An example of a coronary computed tomography angiography (CCTA) exam. The CIAO study looked at patients who have a problem of blood flow limitation and chest pain symptoms in the absence of a 50 percent or more artery narrowing, known as ischemia with no obstructive CAD, or INOCA.

News | Cardiac Imaging | April 03, 2020
April 3, 2020 — Patients who experience chest pain and have abnormal results on a cardiac stress test but who do not