Choosing Wisely: Healthcare Professionals Need Better Insight on CT Impact

Diagnostic tools have been a tremendous force in diminishing the rate of cancer mortality in the United States. Earlier screening and improved technology have together helped diagnosis of early-stage cancers, when the disease is still responsive to treatment. However, exposure of patients to the dangers of certain diagnostic equipment can have unwanted long-term effects, which healthcare providers may be underestimating, according to a new study in the Journal of Medical Imaging and Radiation Sciences.

Researchers from the University of Saskatchewan surveyed the awareness of healthcare professionals—physicians, radiologists, and technologists—regarding the actual dose of radiation that patients are exposed to during a computed tomography (CT) scan. The survey found that while 73% of physicians, 97% of radiologists, and 76% of technologists correctly identified that there is an increased cancer risk from one abdominal-pelvic CT, only 18% of physicians, 28% of radiologists, and 22% of technologists were able to correctly identify the dose in relation to chest x-rays. A significant portion of respondents underestimated the dose that patients receive.

This is a problem, according to the study’s lead author David Leswick, MD, FRCPC, Department of Medical Imaging, College of Medicine, University of Saskatchewan. “Underestimating radiation dose from a CT scan is more concerning than knowing the exact dose level, particularly when it is a vast underestimation, as this may lead to minimization of the risk estimate when considering a test,” Leswick said in a statement.

He explained that the risk of fatal malignancy following a 10-mSv dose of radiation (nearly equivalent to what a patient receives when undergoing an abdomen-pelvis CT) may be as high as 1 in a 1000. This is significant, he said, considering that 2% of cancers in the United States can be attributed to CT.

Healthcare providers, the survey found, also lacked an understanding of the energy source used by other diagnostic equipment, such as magnetic resonance imaging (MRI) and ultrasound, neither of which use ionizing radiation. Yet 20% of physicians, 6% of radiologists, and 7% of technologists attributed radiation exposure to MRIs, and 11% of physicians and 7% of technologists believed an ultrasound used radiation. This false belief could result in underutilization of these modes of imaging, Leswick said.

He believes, “It is important for healthcare professionals to be aware of radiation dose levels and risks from imaging tests for several reasons, including the ability to weigh the risks and benefits of tests, counsel patients on relevant risks, optimize protocols to minimize radiation dose, and select appropriate protocols to minimize radiation dose.”