SIIM: Rad dose monitoring—the good, the bad + the ugly

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 - radiation dose, CT

DALLAS—Radiation dose monitoring initiatives bring both benefits and flaws, according to Jessica Clements, MS, medical physicist and radiation safety officer at Texas Health Presbyterian Hospital in Dallas, during an education session at the Society for Imaging Informatics in Medicine (SIIM) annual meeting.  

Looking at laws

The granddaddy of radiation tracking legislation, California SB 1237, represents the first of what may be many laws and initiatives. The three-part legislation went into effect in January 2011, with the first phase mandating sites report CT and therapy events that exceed certain criteria to the state. In July 2012, the second stage, requiring recording and verification of CT dose, rolled out. In July, all CT sites must be accredited.

On the other side of the country, Massachusetts has enacted legislation that requires American College of Radiology accreditation.

Regulations and rules

In 2011, the Joint Commission leaped into the fray with Sentinel Alert 47, which addressed factors related to radiation risks. The alert focused on the right test and the right dose, effective processes and safe practices, explained Clements.

However, she warned sites against cutting protocols with the sole objective of saving dose. “Images must be of diagnostic quality.”

Another pitfall of the alert and other tracking initiatives is the focus on investigating patterns outside of the range of appropriate dose. That’s because there is a lack of universal dose reference ranges.

The alert also called for tracking of repeat exams to identify causes, which is a bit of a double-edged sword. On the plus side, this suggestion sets the stage for education. On the flip side, “Using software [in a punitive way] to catch people will not prevent anything from happening,” Clements said.

Texas passed new regulations effective May 1, 2013. It requires each facility that performs CT and fluoroscopy to form a radiation protection committee, radiation safety training for staff that uses interventional fluoroscopy and reference values for dose and actions for when values are exceeded.

Clements concluded with a list of the good, the complicated and the ugly related to radiation dose tracking software. The good include:

  • An efficient mechanism for regulatory or accreditation compliance;
  • A platform for population studies;
  • A way to identify studies above reference values and track outliers; and
  • The capability to monitor protocol stability.

Complicated issues include:

  • The difficulty of determining which phantom was used;
  • Variable accuracy of dose-area product meters; and
  • Uncertainties about parameters for identifying cumulative exposure.

Finally, Clements stressed a single ugly trap related to dose monitoring. “Dose metrics are not individual patient doses and should have minimal influence on individual patient imaging decisions.”