Whitney Palmer

Focus on CT Effectiveness, Not Its Theoretical Risk

Published on the Nov. 28, 2012, DiagnosticImaging.com website

By Whitney L.J. Howell

CHICAGO — Every so often, a sudden flurry of articles proclaiming the dangers of radiation dose from CT hits newspapers and magazines, warning patients to resist when their doctors recommend the study. It’s now time for radiologists to start pushing back and having conversations with patients about what CT actually does, industry experts said.

The problem, Michael McNitt-Gray, PhD, a radiological sciences professor at the David Geffen School of Medicine at UCLA, said at this year’s RSNA annual meeting, is that patients — and many providers — don’t understand what CT dose actually means. Consequently, many are vastly overestimating levels of radiation exposure.

That’s why open communication between physician and patient is so critical, said Cynthia McCollough, PhD, biomedical engineering and medical physics professor at the Mayo Clinic in Minneapolis. If providers don’t discuss the significant benefits of CT weighed against its relatively minor, and unverified, radiation risk, patients could forgo studies that might help them avoid a fatal disease.

In fact, McCollough said, her practice sees a substantial number of canceled CT appointments when media reports about radiation risk appear.

“Referring physicians and patients need to know that reducing the use of CT will delay care — our modalities will be clogged, trying to handle the additional volume of studies,” she said. “They won’t know why CT is important if we don’t tell them.”

Education is key to reducing the public’s fear about radiation exposure. And, McCollough recommended having one-on-one conversations when possible and disseminating specialty-specific brochures about the benefits of CT to patients.

It’s also important to reassure patients that radiologists are adhering to the ALARA principle for dosing levels — As Low As Reasonably Achievable. But providers should be wary of swinging the dose pendulum too far. Extremely low doses will negate the test’s efficacy, she said.

For some patients and providers, however, demonstrating low-dose fidelity won’t be enough. In those cases, it can be beneficial to discuss the American College of Radiology (ACR) Appropriateness Criteria that regard CT as an optimal modality for several studies in many disciplines, including neurology, cardiothoracic, vascular, gastroenterology, and urology. In fact, 30 percent to 60 percent of the time, ACR deems CT to be one of the most appropriate for studies, and 10 percent to 40 percent of the time, the ACR considers it the most appropriate study.

It’s also important for patients to understand that multiple CT scans do not increase their cumulative risk of developing cancer, said Robert Dixon, MD, associate professor of vascular interventional radiology at the University of North Carolina at Chapel Hill School of Medicine.

“Repeated CT scans are not at all like chopping down a tree,” he said. “Each axe blow weakens the tree until it topples with the last blow. That doesn’t happen with CT.”

To read the remainder of the story at its original location: http://www.diagnosticimaging.com/conference-reports/rsna2012/content/article/113619/2116769

December 5, 2012 - Posted by wjpalmer | Healthcare | American College of Radiology Appropriateness Criteria, CT benefits versus radiation risks, CT Effectiveness, CT radiation risk, Cynthia McCollough PhD, importance of discussing CT benefits over risks, incorrect media reports about CT radiation risk, media reports about CT radiation risk, Michael McNitt-Gray PhD, myth of cumulative CT exposure, overestimating radiation levels in CT, patient misunderstanding of radiation dose, radiologist misunderstanding of radiation dose, Robert Dixon MD, RSNA Annual Meeting 2012