FDA cites Operator Error as Cause of 385 CT Scan Radiation Overdoses

November 9, 2010

The U.S. Food and Drug Administration (FDA) today announced after a yearlong investigation, that 385 cases of radiation overdoses during computed tomography (CT) brain perfusion scans were likely the result of operator error, not malfunction of the machine.

The FDA investigation began in 2008 after reports of radiation overdoses during CT scans at Cedars Sinai Medical Center in Los Angeles. Since that time, the FDA has investigated cases of 385 patients who suffered radiation overdoses from CT scans performed at five California hospitals and one Alabama hospital.

A CT scan takes cross sectional x-ray images, like slices, of an area of the body such as the brain.

“Improving patient safety is part of our public health mission,” said Jeffrey Shuren, M.D., director of FDA’s Center for Devices and Radiological Health. “Patients should not have to worry that a device designed to diagnose an illness exposes them to unnecessary risks.”

While the probe found that improper use of the CT scanners likely caused the radiation overdoses, the agency did make some recommendations for modification of the machines, and improved protocol and training to prevent such accidents in the future. The FDA sent a letter outlining the changes to the Medical Imaging and Technology Alliance (MITA), the major industry association for radiological imaging manufacturers.

Recommended changes:

• A console notification to alert the operator of a high radiation dose;
• Providing particular information and training on brain-perfusion protocols to all facilities that receiving base CT equipment, whether or not the facilities purchase the related software enabling quantitative analysis of cerebral hemodynamics;

• Clarification of parameters affecting dose, along with clear instructions on how to appropriately set those parameters; and

• Organization of all dose-related information into one section of each user manual, in a dedicated dose manual, or indexed comprehensively in a concordance covering all manuals.

Here is the complete FDA report of the Safety Investigation of CT Brain Perfusion Scans.

The Medical Imaging and Technology Alliance released a statement in response to the FDA’s investigation into CT scan radiation overdoses saying, “As part of our commitment to patient safety, MITA and its members are committed to working with the FDA on MITA’s Dose Check Initiative and the FDA’s recommendations. We agree wholeheartedly with the FDA that “each patient should get the right imaging exam, at the right time, with the right radiation dose.”

On February 9, 2010, the FDA unveiled its Initiative to Reduce Unnecessary Radiation Exposure from Medical Imaging. The goal of the initiative is to reduce unnecessary radiation exposure from three types of medical imaging procedures: computed tomography (CT), nuclear medicine studies and fluoroscopy.

“The amount of radiation Americans are exposed to from medical imaging has dramatically increased over the past 20 years,” said Jeffrey Shuren, M.D., J.D., director of the FDA’s Center for Devices and Radiological Health. “The goal of FDA’s initiative is to support the benefits associated with medical imaging while minimizing the risks.”