Estimation of absorbed dose to adipose tissue from full field digital mammogram using Monte-Carlo simulation

Recent study has found influential role of inflamed adipose (fat) tissue in breast cancer due to low dose radiation. Various inflammatory factors secreted from these irradiated adipose cells might stimulate surrounding tissues including dormant cancer cells. Previously, only glandular tissues were considered most radio-sensitive organ in breast hence no dosimetry studies exist on breast adipose tissues. The objective of this study was full field digital mammogram (FFDM) radiation dosimetry in adipose tissue region of the breast. The average energy deposition in the adipose tissue was simulated as a function of different target-filter materials, quality of x-ray beam (half value layer), percentage of adipose tissue, compressed breast thickness, peak tube voltages (kVp), and tube current-time products (mAs). These variables were taken from recommended imaging techniques published in the technique charts by the manufacturer corresponding to patient’s anatomy and actual mammogram experiment data of anonymous patient’s courtesy. The absorbed doses were simulated and estimated using Monte Carlo N-Particle (MCNP 6) transport codes developed by Los Alamos national laboratory. The obtained dose information’s could be helpful for breast cancer research and provide data necessary for epidemiological studies to improve various risk models such as those presented in BEIR (biological effects of ionizing radiation) or ICRU (International Commission on Radiological Protection) reports.