IAEA focuses on patients' radiation burden

The International Atomic Energy Agency (IAEA) is upping its focus on medical radiation protection by launching a scheme to log patients' X-ray dose each and every time they have an imaging examination. The agency's new radiation Smart Card project aims to provide all patients with a cumulative dose history that can be accessed from electronic health cards and/or digital hospital records.

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The growing use of CT imaging in healthcare has heightened concerns about the link between medical X-ray exposure and cancer. The number of cancers directly attributable to diagnostic imaging is believed to be relatively small. However, the higher the X-ray dose delivered, the greater the risk of cancer later in life. This is particularly the case for paediatric patients.

The radiation dose from a single CT scan is equivalent to that of several hundred chest X-rays, according to IAEA radiation safety experts. Some patients may undergo several CT examinations during the course of diagnosis and treatment, yet the total X-ray dose they receive will not be recorded anywhere.

"We are very good as radiologists, technologists, physicists and members of the healthcare community at paying attention to dose issues for each exam, making sure that the radiation is controlled and that we don't use more than we need," said Donald Frush, professor of radiology and paediatrics at Duke University Medical Centre (Durham, NC). "That said, we have been less good at tracking that information from exam to exam, say, knowing how many CT scans a patient has had."

Such a tally could persuade doctors to exert more caution when referring patients for CT, and to use either low-dose protocols or an alternative modality, such as ultrasound or MRI. Data on patients' lifetime medical X-ray burden should also help clarify the risks posed by prolonged exposure to low levels of ionizing radiation.

The IAEA launched its radiation Smart Card project at a meeting in Vienna last week. The scheme, which has additional financial backing from the US Nuclear Regulatory Commission, will draw together radiation safety experts, equipment manufacturers and IT specialists.

The move has been prompted, in part, by the steady upward growth of diagnostic X-ray examinations. Figures from the United National Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) suggest that the global collective radiation dose due to medical imaging has risen by 17% over the past 10 years.

The IAEA is also concerned that the radiation burden associated with CT is underestimated by some doctors. Scan times may have shortened considerably over the past few years with the roll-out of more sophisticated CT technology, but this does not necessarily mean that the dose used to image patient anatomy is any lower.

"Looking at the way that things are going, if we do not do something now, people are going to ask us: 'Why did you not take action?'," said IAEA radiation safety specialist Madan Rehani.

Much progress has already been made in the development of e-health cards and digital medical records, Rehani explained. The IAEA wants to make sure that the opportunities that these technologies present for radiation protection are not overlooked.

"If we do not talk about patient radiation dose, then it will not be included in these plans. What we want is to see that dose and examination information are also on the agenda," Rehani said.

The Smart Card project is expected to deliver "tangible results" within the next three to five years. The IAEA will also continue to deliver information for health professionals on the safe use of ionizing radiation through a dedicated web site (rpop.iaea.org).
About the author

Paula Gould is a contributing editor on medicalphysicsweb.