X-ray spectra calculation for different target-filter of mammograms using MCNP Code

Mammography is one of the most important imaging techniques to diagnose breast cancer. It is perhaps the single most important innovation in breast cancer control. The importance of mammography is directly related to its value in the early detection and management of breast cancer. Mammography detects approximately 2-3 times as many early breast cancers as physical exams. Breast cancer is the second cause of women death after lung cancer in USA(1). Recently, further to Mo-Mo target-filter combination in X-ray tubes of mammograms, other new array of target-filter such as MoRh, Rh-Rh W-Rh, Mo-Al and Rh-Al have also been used(2). Thilander et al.(3) and Jennings et al.(4) reported that the average glandular dose to the breast tissue can be reduced about 50% if a W-Rh combination is used instead of Mo-Mo. Also, the Monte Carlo result of Dance et al. shows that the W-Rh and Rh-Al combinations are more useful as alternatives to the standard Mo-Mo for digital mammography(2). In this paper, the X-ray spectra for different target-filter combinations by Monte Carlo method using MCNP code version 4C was calculated(5). Monte Carlo method is a powerful tool to study and optimize ionizing radiation systems such as mammograms(6, 7).