Nav: Home

Study reveals low adoption of advice to reduce nuclear cardiology radiation exposure

May 09, 2017

Vienna, Austria - 9 May 2017: A study in 65 countries has revealed low adoption of International Atomic Energy Agency recommendations to reduce nuclear cardiology radiation exposure. The research is presented today at ICNC 2017 by Dr Edward Hulten, a cardiologist at the Walter Reed National Military Medical Center, Bethesda, USA.1

Nuclear cardiology uses small amounts of radioactive tracers which 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.

Dr 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 ionising 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.2, 3

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" artefacts.

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.

Dr Hulten said: "When the 9 mSv recommendation was made in 2010 it was suggested that it should be achieved in 50% 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 Dr 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."

Dr 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."
-end-


European Society of Cardiology

Related Heart Disease Articles:

Where you live could determine risk of heart attack, stroke or dying of heart disease
People living in parts of Ontario with better access to preventive health care had lower rates of cardiac events compared to residents of regions with less access, found a new study published in CMAJ (Canadian Medical Association Journal).
Older adults with heart disease can become more independent and heart healthy with physical activity
Improving physical function among older adults with heart disease helps heart health and even the oldest have a better quality of life and greater independence.
Dietary factors associated with substantial proportion of deaths from heart disease, stroke, and disease
Nearly half of all deaths due to heart disease, stroke, and type 2 diabetes in the US in 2012 were associated with suboptimal consumption of certain dietary factors, according to a study appearing in the March 7 issue of JAMA.
Certain heart fat associated with higher risk of heart disease in postmenopausal women
For the first time, researchers have pinpointed a type of heart fat, linked it to a risk factor for heart disease and shown that menopausal status and estrogen levels are critical modifying factors of its associated risk in women.
Maternal chronic disease linked to higher rates of congenital heart disease in babies
Pregnant women with congenital heart defects or type 2 diabetes have a higher risk of giving birth to babies with severe congenital heart disease and should be monitored closely in the prenatal period, according to a study published in CMAJ.
Novel heart valve replacement offers hope for thousands with rheumatic heart disease
A novel heart valve replacement method is revealed today that offers hope for the thousands of patients with rheumatic heart disease who need the procedure each year.
Younger heart attack survivors may face premature heart disease death
For patients age 50 and younger, the risk of premature death after a heart attack has dropped significantly, but their risk is still almost twice as high when compared to the general population, largely due to heart disease and other smoking-related diseases The risk of heart attack can be greatly reduced by quitting smoking, exercising and following a healthy diet.
Citrus fruits could help prevent obesity-related heart disease, liver disease, diabetes
Oranges and other citrus fruits are good for you -- they contain plenty of vitamins and substances, such as antioxidants, that can help keep you healthy.
Gallstone disease may increase heart disease risk
A history of gallstone disease was linked to a 23 percent increased risk of developing coronary heart disease.
Americans are getting heart-healthier: Coronary heart disease decreasing in the US
Coronary heart disease is one of the leading causes of death in the United States.

Related Heart Disease Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Setbacks
Failure can feel lonely and final. But can we learn from failure, even reframe it, to feel more like a temporary setback? This hour, TED speakers on changing a crushing defeat into a stepping stone. Guests include entrepreneur Leticia Gasca, psychology professor Alison Ledgerwood, astronomer Phil Plait, former professional athlete Charly Haversat, and UPS training manager Jon Bowers.
Now Playing: Science for the People

#524 The Human Network
What does a network of humans look like and how does it work? How does information spread? How do decisions and opinions spread? What gets distorted as it moves through the network and why? This week we dig into the ins and outs of human networks with Matthew Jackson, Professor of Economics at Stanford University and author of the book "The Human Network: How Your Social Position Determines Your Power, Beliefs, and Behaviours".