CA: Despite shortcomings, appropriateness criteria can control rad exposure

The American Cancer Society, in an effort to reduce future projected cancers from diagnostic imaging procedures, outlined some limitations and enhancements to current appropriateness criteria used for making decisions about imaging and also offered some CT exam recommendations for clinicians in an article published online Feb. 3 in CA: A Cancer Journal for Clinicians.

“The 600 percent increase in medical radiation exposure to the U.S. population since 1980 has provided immense benefit, but increased potential future cancer risks to patients. Most of the increase is from diagnostic radiologic procedures,” wrote Martha S. Linet, MD, MPH, of the National Cancer Institute in Bethesda, Md., and colleagues.

The American College of Radiology's (ACR) Appropriateness Criteria currently addresses more than 175 topics with over 850 variants, yet there are some limitations, according to the authors. The guidelines have not all been systematically evaluated using an evidence-based approach. Some radiologic procedures lack measures such as sensitivity and specificity, while others lack rigorous evaluation through randomized trials.

“These major limitations, in conjunction with the rapid adoption and use of new imaging technologies, limit more comprehensive use of evidence-based approaches,” wrote the authors.

Another problem is ACR Appropriateness Criteria have low utilization rates, likely stemming from a lack of awareness of the resources.

Despite the limitations, Linet et al explain that appropriateness criteria, when used, can achieve more appropriate test ordering. One example they cited was an Israeli managed care preauthorization program based on the ACR Appropriateness Criteria and the U.K. Royal College of Radiology guidelines that cut CT and MRI rates by 33 and 9 percent, respectively, in the early 2000s. Combining the criteria with decision support software has been shown to be effective at decreasing imaging utilization.

“It is also essential for reports of all CT and other radiologic examinations to be incorporated into medical records immediately to reduce the frequency of repetition of the same or similar diagnostic radiologic procedures,” wrote the authors.

Linet and colleagues provided eight recommendations for clinicians performing CT scans:

1. Become knowledgeable about the radiation doses for the imaging studies.
2. Consider ultrasound and MRI when these are appropriate alternatives since these procedures do not subject the patient to ionizing radiation.
3. Do not order a higher radiation dose study if a lower dose study (or an imaging study that does not use ionizing radiation) can provide the clinical information needed.
4. All requests for imaging studies should be justified (e.g., when all benefits and risks are considered, the study should be expected to do more good than harm).
5. Available aids for justification, such as the ACR’s Appropriateness Criteria and the [American College of Cardiology]’s Appropriate Use Criteria for Cardiac CT, should be utilized to provide guidance for choosing the most appropriate imaging exam.
6. Unnecessary imaging studies (duplicate studies and those that are not medically necessary) should not be performed.
7. In general, neither screening nor elective x-ray examinations should be performed on pregnant women.
8. Refer patients who require imaging studies to a facility that strives to optimize radiation dose, so that imaging is performed with the least amount of radiation necessary to provide adequate image quality.