Doctors routinely order CT scans as diagnostic tools. But many are ill-informed about the cancer risks associated with this imaging technology, a new study suggests.
Patients who undergo CT scans are exposed to harmful ionizing radiation, which could affect their lifetime risk for developing cancer, Canadian researchers said.
“Underestimating radiation dose from a CT scan … may lead to minimization of the risk estimate when considering a test,” said the study’s lead investigator, Dr. David Leswick, of the medical imaging department at the University of Saskatchewan College of Medicine.
For the study, the researchers surveyed doctors, radiologists and imaging technologists about radiation exposure from CT scans.
They found the vast majority knew that one abdominal-pelvic CT increases patients’ risk for cancer. But many didn’t know how the dose compared to radiation from a standard chest X-ray.
The average radiation dose from an abdominal-pelvic CT scan is roughly the equivalent of 100 to 250 chest X-rays, the researchers said.
But only about one in five doctors and technologists and just 28 percent of radiologists were able to correctly identify the CT scan dose in relation to X-rays, the study found.
Nearly half of the doctors, four out of five radiologists and 63 percent of technologists accurately estimated or overestimated the dose, the study found.
Many others underestimated the dose level, which was more concerning, the researchers said.
The findings were published recently in the Journal of Medical Imaging and Radiation Sciences.
As doctors order CT scans with increasing frequency, accurately understanding the risks of radiation exposure is significant, Leswick and his colleagues said in a journal news release.
The U.S. Food and Drug Administration provides more on radiation risks from CT scans.