YouTube videos weigh threat of CT radiation exposure

June 4, 2009

The International Atomic Energy Agency and Brigham and Women’s Hospital have turned to YouTube to educate the public and physicians about the risks of exposure to CT-generated ionizing radiation and strategies to address them.

The International Atomic Energy Agency and Brigham and Women's Hospital have turned to YouTube to educate the public and physicians about the risks of exposure to CT-generated ionizing radiation and strategies to address them.

The IAEA backs a plan to use electronic medical records maintained on smart cards to track the accumulation of radiation exposure from diagnostic imaging and therapy over time for individual healthcare consumers. In a video interview, Dr. Aaron D. Sodickson, assistant director of emergency radiology at Brigham and Women's, discusses his hospital's plan to develop an automated decision-support tool to help physicians weigh the risks and benefits of CT when ordering procedures.

The IAEA video published online June 4 acknowledges diagnostic imaging's superlative contributions to medical science. However, it also warns that overutilization of high-tech procedures such as CT scanning may be unnecessarily exposing patients to increased doses of ionizing radiation.

The agency's video compares the average CT scan dose with that of approximately 500 chest x-rays. It goes further by stating that such dosage could increase patients' lifetime risk of developing cancer, especially if they are repeatedly exposed to further exams. A brief interview with a practicing radiologist underscores concern among imagers about unprecedented growth in the volume of procedures involving increasingly younger patients.

The agency's goal is not to scare people off about medical imaging but to cut down on unnecessary radiation exposure, said IAEA radiation safety specialist Dr. Madan Rehani. New studies suggest that radiation dose reductions of up to 50% could be achieved.

That potential calls for action, Rehani says during the YouTube presentation.

The increasing use of electronic medical records enables the use of smart cards to track imaging procedures and their related radiation doses, according to Dr. Donald P. Frush, American College of Radiology Pediatric Commission chair and member of the Alliance for Radiation Safety in Pediatric Imaging, who is also featured in the video. The IAEA video suggests that new imaging technologies should be able to automatically include the radiation dose data from these procedures into the patient's individual record.

A related video featuring Sodickson provides a sobering account about the potential implications of cumulative radiation exposure.

Sodickson and colleagues retrospectively evaluated the potential effects of cumulative radiation exposure for more than 31,000 patients during more than 20 years of CT scanning experience at Brigham and Women's. They found that at least a third of these patients underwent five or more CT scans on average, while about 1% of them underwent nearly 40 CT scans during the same time. By using the cumulative dose history, they calculated the approximate cancer risk. They found that about 7% of these patients had increased their lifetime chance of developing cancer by at least 1%.

The study was featured in the March issue of the Harvard Health Letter.

An additional 1% increase in cancer risk appears small compared with the known 42% lifetime risk that U.S. residents have for developing cancer. However, it is high enough in his opinion to potentially affect the risk-versus-benefit decision physicians make when ordering medical procedures.

Brigham and Women's radiologists are developing a decision-support tool to help them weigh their options, Sodickson said. They plan to have the program ready for use this year.