Radiation Doses and Cancer Risks from Breast Imaging Studies

Purpose: To compare radiation doses and lifetime attributable risks (LARs) of radiation-induced cancer incidence and mortality from breast imaging studies involving the use of ionizing radiation. Materials and Methods: Recent literature on radiation doses from radiologic procedures and organ doses from nuclear medicine procedures, along with Biologic Effects of Ionizing Radiation (BEIR) VII age-dependent risk data, is used to estimate LARs of radiation-induced cancer incidence and mortality from breast imaging studies involving ionizing radiation, including screen-film mammography, digital mammography, digital breast tomosynthesis, dedicated breast computed tomography, breast-specific gamma imaging (BSGI), and positron emission mammography (PEM). Results: Two-view digital mammography and screen-film mammography involve average mean glandular radiation doses of 3.7 and 4.7 mGy, respectively. According to BEIR VII data, these studies are associated, respectively, with LARs of fatal breast cancer of 1.3 and 1.7 cases per 100 000 women aged 40 years at exposure and less than one case per one million women aged 80 years at exposure. Annual screening digital or screen-film mammography performed in women aged 40-80 years is associated with an LAR of fatal breast cancer of 20-25 cases in 100000. A single BSGI study involving a label-recommended dose of 740-1100 MBq (20-30 mCi) of technetium 99m-sestamibi is estimated to involve an LAR of fatal cancer that is 20-30 times that of digital mammography in women aged 40 years. A single PEM study involving a labeled dose of 370 MBq (10 mCi) of fluorine 18 fluorodeoxyglucose is estimated to involve an LAR of fatal cancer that is 23 times higher than that of digital mammography in women aged 40 years. Conclusion: A single BSGI or PEM study is associated with a fatal radiation-induced cancer risk higher than or comparable to that of annual screening mammography in women aged 40-80 years. (C) RSNA, 2010