X-ray induced formation of γ-H2AX foci after full-field digital mammography and digital breast-tomosynthesis.
OBJECTIVE
To determine in-vivo formation of x-ray induced γ-H2AX foci in systemic blood lymphocytes of patients undergoing full-field digital mammography (FFDM) and to estimate foci after FFDM and digital breast-tomosynthesis (DBT) using a biological phantom model.


METHODS
The study complies with the Declaration of Helsinki and was performed following approval by the ethic committee of the University of Erlangen-Nuremberg. Written informed consent was obtained from every patient. For in-vivo tests, systemic blood lymphocytes were obtained from 20 patients before and after FFDM. In order to compare in-vivo post-exposure with pre-exposure foci levels, the Wilcoxon matched pairs test was used. For in-vitro experiments, isolated blood lymphocytes from healthy volunteers were irradiated at skin and glandular level of a porcine breast using FFDM and DBT. Cells were stained against the phosphorylated histone variant γ-H2AX, and foci representing distinct DNA damages were quantified.


RESULTS
Median in-vivo foci level/cell was 0.086 (range 0.067-0.116) before and 0.094 (0.076-0.126) after FFDM (p = 0.0004). In the in-vitro model, the median x-ray induced foci level/cell after FFDM was 0.120 (range 0.086-0.140) at skin level and 0.035 (range 0.030-0.050) at glandular level. After DBT, the median x-ray induced foci level/cell was 0.061 (range 0.040-0.081) at skin level and 0.015 (range 0.006-0.020) at glandular level.


CONCLUSIONS
In patients, mammography induces a slight but significant increase of γ-H2AX foci in systemic blood lymphocytes. The introduced biological phantom model is suitable for the estimation of x-ray induced DNA damages in breast tissue in different breast imaging techniques.
Institute of Radiology, University Erlangen/Nuremberg, Erlangen, Bavaria, Germany. dr.siegfried.schwab@gmx.net
Siegfried A
SA
Schwab
Michael
M
Brand
Ina-Kristin
IK
Schlude
Wolfgang
W
Wuest
Martina
M
Meier-Meitinger
Luitpold
L
Distel
Ruediger
R
Schulz-Wendtland
Michael
M
Uder
Michael A
MA
Kuefner
D000328:Adult; D000368:Aged; D000818:Animals; D015415:Biomarkers / Q000097:blood; D001940:Breast; D004249:DNA Damage; D005260:Female; D015870:Gene Expression / Q000528:radiation effects*; D064368:Healthy Volunteers; D006657:Histones / Q000097:blood / Q000235:genetics*; D006801:Humans; D008214:Lymphocytes / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects*; D008321:Mammary Glands, Animal / Q000000981:diagnostic imaging*; D008327:Mammography / Q000009:adverse effects*; D008875:Middle Aged; D019047:Phantoms, Imaging; D011856:Radiographic Image Enhancement / Q000379:methods; D011874:Radiometry; D013552:Swine; D014056:Tomography, X-Ray; D014965:X-Rays / Q000009:adverse effects
D015415:Biomarkers; C468783:H2AX protein, human; D006657:Histones