The amount of radiation women receive from annual mammograms does not increase their likelihood of developing thyroid cancer, according to the American College of Radiology (ACR) and the Society of Breast Imaging (SBI).
The two associations made the announcement on April 4 in response to what they called an erroneous media report posted on the website of the Dr. Oz Show. The report noted that even though the radiation dose from routine dental x-rays, chest x-rays, and mammograms is small, "some worry about this as a thyroid-damaging source."
The joint ACR-SBI statement said that during a mammogram, the thyroid is not exposed to the direct x-ray beam used to image the breast and receives only a small amount of scattered x-rays (less than 0.005 mGy, and equivalent to 30 minutes of the natural background radiation received by all Americans from natural sources).
For annual mammography screening between the ages of 40 and 80, the cancer risk from this amount of radiation scattered to the thyroid is small, according to the groups: less than one in 17.1 million women screened. This small risk should be balanced with the fact that using a thyroid shield during mammography can interfere with exam positioning and result in artifacts, both of which can negatively affect image quality and interfere with diagnosis, according to the ACR and the SBI.
