Cardiac imaging dose should prompt talk with patient

Providers should inform patients of radiation exposure with cardiac imaging procedures and doses of more than 20 mSv warrant more extensive discussion, according to recommendations published online Feb. 12 in the Journal of the American College of Cardiology.

The recommendations originally came out of a 2012 symposium sponsored by the National Institutes of Health’s National Heart, Lung, and Blood Institute.

Symposium participants sought to identify the major elements of an accountability framework that addresses radiation safety issues for the patient, the laboratory and the overall population of people with cardiovascular disease.

The document’s authors, led by Andrew J. Einstein, MD, PhD, of Columbia University Medical Center in New York, explained that one of the major recommendations was to inform all patients of radiation exposure. Both the ordering provider and the imaging provider should disclose potential risks from radiation. Doses of 3 mSv or less do not require extensive discussion or written consent, but doses exceeding 20 mSv should involve detailed discussion or written informed consent.

Communication with patients, however, should take several factors into consideration. First, most Americans do not easily understand statistics, so providers should avoid too many numbers in their discussions. Among the other communication recommendations were to clarify the difference between baseline cancer risk and cancer risk after exposure to radiation and to use visual aids, such as pictographs.

In terms of safety issues in the laboratory, the recommendations focused on the need for providers to know about radiation doses and be aware of ways to lower exposure. Requirements for laboratory accreditation should focus on reducing radiation dose while simultaneously optimizing diagnostic performance, and laboratories should have quality and safety metrics in place.

One recommendation was for diagnostic reference levels for a variety of cardiac imaging procedures, a new and time-consuming undertaking. Another recommendation was for laboratories to keep track of radiation safety metrics using a database as a quality performance measure. Some of these data should ultimately be made public.

Population-based efforts to reduce radiation exposure should be based on multiple strategies, such as minimizing testing for reasons deemed inappropriate or rarely appropriate. One way to promote more widespread use of such criteria is to incorporate decision-support tools when the provider orders a procedure. The recommendations also included using population-based registries to track radiation.

Although the imaging technology currently available allows for noninvasive, routine testing, the authors argued that providers who utilize it must accept responsibility for safe and appropriate use.

“The creation of the patient-centered imaging laboratory that prioritizes patient safety and effectiveness will require sizeable changes to the culture of imaging, which now focuses on volume and efficiency,” they wrote.