User error, not technological problems, is to blame for cases of excess radiation in computed tomography scans, the U.S. Food and Drug Administration says.
The FDA has been investigating reports that patients undergoing CT brain perfusion scans were accidently exposed to excess radiation. The FDA announced this week it found that when properly used, the CT scanners did not malfunction. Rather, it's likely improper use of the scanners resulted in the overdoses.
Nevertheless, the FDA identified a series of steps intended to enhance the safety of these procedures. The steps could reduce the likelihood of radiation overexposure in the event of CT scanners' improper use.
Back in October 2009, the FDA encouraged CT facilities to review their protocols and make sure that the values displayed on the control panel corresponded to the doses normally associated with the protocol. Based on its investigation to date, the FDA made additional recommendations to facilities. Among them:
- Assess whether patients received excess radiation during CT perfusion scans.
- Review radiation dosing protocols for all CT perfusion scans to ensure the correct dose is planned for each study.
- Implement quality control procedures to ensure dosing protocols are followed every time, and that the planned amount of radiation is administered.
- Check the display panel before performing each scan to make sure the amount of radiation to be delivered is appropriate for the individual patient.
- Be certain, and document, that radiologic technologists are trained on the specific scanner and for the specific imaging protocol they are using.
- CT operators should be specifically trained on dose-saving features, such as automatic exposure control, before using them.
Additionally, in a letter to the Medical Imaging and Technology Alliance, the major professional industry organization for manufacturers of CT scanners and other radiological imaging devices, FDA shared the results of the investigation and addressed possible CT equipment enhancements that could improve patient safety.
Among the changes under consideration:
- 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 receive base CT equipment;
- 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.
Begun in 2009, FDA's investigation included information from the states and facilities where radiation overdoses occurred from 2008 to Oct. 26, 2010. The agency also inspected CT scanner equipment manufacturers. Since the investigation began, FDA learned of at least 385 patients who received excessive radiation from CT brain perfusion scans, many undergoing the test to confirm the presence of a stroke, performed at five hospitals in California and one in Alabama.
While unnecessary radiation exposure should be avoided, a medically needed CT scan has benefits that outweigh the radiation risks, the FDA emphasized in its statement. (The announcement comes days after a large national study by the National Cancer Institute that found screening current or former heavy smokers with a CT scan can reduce deaths from lung cancers by 20 percent.)
Dave Fisher, executive director of MITA, tells HealthLeaders Media that his organization looks forward to working with the FDA in the coming weeks; he points out that the recommendations in FDA's letter are issues MITA has been working on with FDA over the last year.
Although the problems were not attributed to CT scanner malfunction, he stressed MITA's commitment to developing technologies that reduce radiation levels—and to educating users: "Our companies provide training? and we're happy to provide additional training as appropriate."
The FDA's complete report can be found here.