TUESDAY, Nov. 27 (HealthDay News) -- Use of medical imaging has surged in the past decade, and now a new study suggests the trend carries a risk: Having multiple cardiac and chest CT scans may increase the chances of breast cancer, researchers report.
The risk appears higher for younger women, the preliminary research showed. For example, for a girl or young woman under age 23 who has two high-dose cardiac or chest CT scans, the risk of developing breast cancer in the next 10 years doubles, the researchers found.
"There's a sense that medical imaging is a panacea, but women need to know that there is a trade-off with these exams," said study senior author Rebecca Smith-Bindman, a professor of radiology and biomedical imaging epidemiology and biostatistics at the University of California, San Francisco. "If the exam is necessary, the risk is small but almost always worth it. If the test isn't necessary, it's something to avoid."
Still, a woman's overall risk is low, she said. The actual rate for young women who have had two scans is about eight cases of breast cancer per 100,000 women, up from four cases per 100,000, Smith-Bindman said.
The study, scheduled for presentation Tuesday at the Radiology Society of North America annual meeting in Chicago, included data on radiation exposure from the Group Health insurance database. The researchers reviewed CT scan-dose data on more than 1,600 females between 2000 and 2010, and used a statistical modeling technique to estimate the average radiation doses they received.
The researchers found that the use of CT scans increased over time. In 2000, there were about 100 scans per 1,000 women enrolled. By 2010, that number had reached 192 per 1,000 women. Almost half of the scans in 2010 exposed the chest to radiation. The dose of radiation varied by test, with higher doses delivered during scans of the heart or chest.
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