ESC: Cardiologists should be Mindful of Radiation Doses


cardio radiation

Based on a position report from the European Society of Cardiology (ESC), cardiologists must be mindful of the radiation dosages related with the tests they order or prescribe for their patients.

Moreover, despite the fact that cardiovascular imaging accounts for about 40% of medical radiation exposure in the general population (after excluding radiotherapy), cardiologists are often un-aware of the radiation doses, and subsequent risks, from the exams, Eugenio Picano, MD, PhD, of the Institute of Clinical Physiology in Pisa, Italy, and peers wrote and published online in the European Heart Journal.

Therefore in order to address such a point, representatives from the ESC's Associations of Cardiovascular Imaging, Percutaneous Cardiovascular Interventions, and Electrophysiology reviewed the reports regarding the effective radiation doses from a range of imaging exams, discovering that doses ranged from about 1 to 60 milliSievert (mSv). For comparison, the natural background radiation globally is about 2.4 mSv per person annually.

"All other considerations being equal, it is not recommended to perform tests involving ionizing radiation when the desired information can be obtained with a non-ionizing test with comparable accuracy. If you perform a test that utilizes ionizing radiation, choose the one with the lowest dose and be aware of the many factors modulating dose," the authors wrote.

The authors also added that the actual administered dose should be documented in patient records.

“Because radiation used in imaging tests is proven to cause cancer, cardiologists should make every effort to give 'the right imaging exam, with the right dose, to the right patient,” they continued.

Additionally, cardiovascular imaging and interventional methods that call for radiation are being employed more often, raising concerns about both the short- and long-term risks of radiation exposure, such as tissue damage or cancer. The concerns revolve around patients, but certain practitioners, mainly interventional cardiologists and cardiac electrophysiologists, can have elevated exposures, as well.

Consequently, cardiologists "have a particular responsibility to avoid unjustified and non-optimized use of radiation," the authors noted.

A list of mean doses of radiation with common procedures could help cardiologists consider the risks and benefits of a certain test for a certain patient, and the paper includes a table with such values.

For instance, the mean effective radiation dose for a percutaneous coronary intervention (PCI), a 64-slice coronary CT angiogram, or an ablation procedure is about 15 mSv, equal to 750 chest x-rays or exposure to approximately 6 years of background radiation.

"The available epidemiological evidence linking increased cancer risk to radiation exposure is now strong for doses greater than 50 mSv, also for diagnostic medical exposures. In contemporary imaging practice, doses greater than 50 to 100 mSv are sometimes reached after cumulative exposures in a single hospital admission and not infrequently by a patient in multiple examinations and diagnostic or interventional procedures for a single imaging technique and even in a single admission,” the authors wrote.

The cancer risks differ depending on patient age and sex, with higher risks accounting more in females and children.

One way to raise awareness of the radiation doses accompanying different cardiovascular exams suggested by Picano and co-workers was the use of an informed consent form that would have a projected reference dose in several easy-to-understand formats, including chest x-ray equivalents and time frames of natural background radiation. After the test, the actual administered radiation dose would be documented in patient and lab records and could be provided to the patient upon request.

"This simple consent process will gently force the doctor to learn what he/she already should know, enabling him/her to make more responsible choices," the authors wrote.