title: Effects of Breast Shielding during Heart Imaging on DNA Double-Strand-Break Levels: A Prospective Randomized Controlled Trial.
abstract: Purpose To examine the effect of breast shielding on blood lymphocyte deoxyribonucleic acid (DNA) double-strand-break levels resulting from in vivo radiation and ex vivo radiation at breast-tissue level, and the effect of breast shielding on image quality. Materials and Methods The study was approved by institutional review and commpliant with HIPAA guidelines. Adult women who underwent 64-section coronary computed tomographic (CT) angiography and who provided informed consent were prospectively randomized to the use (n = 50) or absence (n = 51) of bismuth breast shields. Peripheral blood samples were obtained before and 30 minutes after in vivo radiation during CT angiography to compare DNA double-strand-break levels by γ-H2AX immunofluorescence in blood lymphocytes. To estimate DNA double-strand-break induction at breast-tissue level, a blood sample was taped to the sternum for ex vivo radiation with or without shielding. Data were analyzed by linear regression and independent sample t tests. Results Breast shielding had no effect on DNA double-strand-break levels from ex vivo radiation of blood samples under shields at breast-tissue level (unadjusted regression: β = .08; P = .43 versus no shielding), or in vivo radiation of circulating lymphocytes (β = -.07; P = .50). Predictors of increased DNA double-strand-break levels included total radiation dose, increasing tube potential, and tube current (P < .05). With current radiation exposures (median, 3.4 mSv), breast shielding yielded a 33% increase in image noise and 19% decrease in the rate of excellent quality ratings. Conclusion Among women who underwent coronary CT angiography, breast shielding had no effect on DNA double-strand-break levels in blood lymphocytes exposed to in vivo radiation, or ex vivo radiation at breast-tissue level. At present relatively low radiation exposures, breast shielding contributed to an increase in image noise and a decline in image quality. The findings support efforts to minimize radiation by primarily optimizing CT settings. (©) RSNA, 2016 Clinical trial registration no. NCT02617888 Online supplemental material is available for this article.
authors.affiliation: From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.).
authors.forename: Michael K
authors.initials: MK
authors.lastname: Cheezum
authors.affiliation: From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.).
authors.forename: Christophe E
authors.initials: CE
authors.lastname: Redon
authors.affiliation: From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.).
authors.forename: Allison S
authors.initials: AS
authors.lastname: Burrell
authors.affiliation: From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.).
authors.forename: Anthony S
authors.initials: AS
authors.lastname: Kaviratne
authors.affiliation: From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.).
authors.forename: Jody
authors.initials: J
authors.lastname: Bindeman
authors.affiliation: From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.).
authors.forename: Daisuke
authors.initials: D
authors.lastname: Maeda
authors.affiliation: From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.).
authors.forename: Houria
authors.initials: H
authors.lastname: Balmakhtar
authors.affiliation: From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.).
authors.forename: Ashly
authors.initials: A
authors.lastname: Pezel
authors.affiliation: From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.).
authors.forename: Piotr
authors.initials: P
authors.lastname: Wisniewski
authors.affiliation: From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.).
authors.forename: Panfilo
authors.initials: P
authors.lastname: Delacruz
authors.affiliation: From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.).
authors.forename: Binh
authors.initials: B
authors.lastname: Nguyen
authors.affiliation: From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.).
authors.forename: William M
authors.initials: WM
authors.lastname: Bonner
authors.affiliation: From the Department of Medicine (Cardiology Service) (M.K.C., A.S.K., J.B., T.C.V.) and Department of Radiology (B.N.), Walter Reed National Military Medical Center, 8901 Wisconsin Ave, Bethesda, MD 20889; Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, Bethesda, Md (C.E.R., A.S.B., D.M., H.B., W.M.B.); Institute of Biomedical Sciences, The George Washington University, Washington, DC (A.S.B.); George Mason University, Fairfax, Va (H.B.); Uniformed Services University of Health Sciences, Bethesda, Md (A.P., P.W.); and Department of Medicine, San Antonio Military Medical Center, San Antonio, Tex (P.D.).
authors.forename: Todd C
authors.initials: TC
authors.lastname: Villines
mesh_terms: D001940:Breast / Q000528:radiation effects*; D000072226:Computed Tomography Angiography; D017023:Coronary Angiography; D053903:DNA Breaks, Double-Stranded / Q000528:radiation effects*; D005260:Female; D006331:Heart Diseases / Q000000981:diagnostic imaging*; D006801:Humans; D008875:Middle Aged; D011446:Prospective Studies; D011829:Radiation Dosage; D011835:Radiation Protection / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted