Breast dose distribution studies in magnification mammography using Monte Carlo simulation

• Κύριος συγγραφέας: Κουταλώνης, Ματθαίος Β.
• Άλλοι συγγραφείς: Παναγιωτάκης, Γεώργιος
• Μορφή: Thesis
• Γλώσσα: Greek
• Έκδοση: 2008
• Θέματα: Average glandular dose; Magnification mammography; Monte Carlo simulation; Μέση δόση στο μαζικό αδένα του μαστού; Μεγεθυντικές λήψεις στη μαστογραφία; Προσομοίωση Monte Carlo; 618.190 757 2

Magnification mammography is a special technique used in cases where breast complaints are noticed by a woman or when an abnormality is found in a screening mammogram. The carcinogenic risk in mammography is related to the dose deposited in the glandular tissue of the breast rather than the adipose, and Average Glandular Dose (AGD) is the quantity taken into consideration during a mammographic exam. Direct measurement of the AGD is not feasible during clinical practice and thus, the incident air Kinetic Energy Released per unit of MAss (KERMA) on the breast surface is used to estimate the glandular dose, with the help of proper conversion factors. Additional conversion factors adapted for magnification and tube voltage are calculated, using Monte Carlo simulation. The effect of magnification factor, tube voltage and various anode/filter material combinations on AGD, ESD and PDD is also studied. Results demonstrate that, for fixed glandularity, the estimation of AGD utilizing conversion factors depends on magnification factor, anode/filter combination and tube voltage applied. AGD was found to increase mainly with filter material’s kabsorption edge, filter’s Al thickness, anode material’s k-emission edge and tube voltage. Rh/Nb, W/Zr, W/Nb, W/Mo and Mo/Nb are combinations resulting in lower AGD and higher ESD, compared to the Mo/Mo one.