Hospitals and imaging centers are challenged to reduce radiation exposure, but it’s a difficult task without access to clear-cut guidelines. The University of California developed and tested a new approach that may lead to CT radiation dose standardization.

Health care providers find it hard to determine the appropriate radiation dose that maintains diagnostic accuracy and minimizes radiation exposure. Since there is no concrete standard, each institution has to make independent decisions about what dose to use.

Researchers at the five UC academic medical centers collected data on all diagnostic CT exams performed between October 2013 and December 2014, which amounted to more than 158,000 CT scans. They then used the data to create reports for chest, abdomen and head CT exams.
The reports were given to each medical center and meetings were held to share both successful and failed strategies for lowing radiation dose without affecting diagnostic performance. They then shared and implemented what they learned in their own medical centers.

The research team found that this approach has the potential to reduce the mean effective radiation dose for standard chest CT exams by almost 19 percent. For head CT exams, the doses varied less over time.

For abdominal CT exams, the mean dose could be lowered by 25 percent. The researchers estimated that if the approach were applied to all abdominal CT exams performed in the U.S., it would result in the reduction of about 12,000 cancers per year.

“These findings indicate a benefit to reviewing institutional radiation doses, providing feedback to radiology practices using an easy and comprehensive format, and bringing professionals together to discuss strategies for improvement,” Dr. Rebecca Smith-Bindman, senior author and professor at UC San Francisco, said in a statement.

She mentioned that a randomized trial, rather than this observational study, could provide more definitive evidence on the connection between dose feedback and dose level. The National Institutes of Health has provided her with funding to conduct a randomized trial, which is currently underway.

A commentary that accompanied the study in JAMA Internal Medicine stated that it provides a “valuable road map” for hospitals and other treatment facilities. Previous radiation improvement programs have failed in the past, but this one was successful partly because medical experts were given authority and accountability to implement appropriate changes.

“By creating a venue for leaders from the five institutions to collectively define and standardize best practices, with allowance for flexibility within each institution … the study team hypothesized that greater reductions (and less variation) in radiation exposure could be achieved. And they were right,” wrote the authors of the commentary.

But they believe two questions remain, regarding the specific changes that were made at each institution that achieved the dose reductions, and whether the dose reductions led to changes in diagnostic accuracy.

“This will certainly be a factor for future institutions to consider,” they wrote.

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