The absorbed doses in digital mammography

Abstract

Background: Digital mammography is a good screening examination for breast cancer because it has high sensitivity and specificity. But because of radiation in examination and high sensitivity of breast tissue to it, digital mammography has a risk for breast to be stimulated to cancer by radiation. So it is necessary to evaluate the radiation amount in mammography which can be done by finding the absorbed dose of breast and comparing it to the standard level of American Collage of Radiation which recommended 3 milligrays per image at the compressed breast thickness 4.5 centimetres.
Objective: To study the absorbed doses of breasts in the patients undergoing digital mammography at Surin Hospital.
Material and methods: This was a retrospective study of 740 patients underwent digital mammography at Surin Hospital, between October 1, 2012 and September 30, 2013, 40-60 years of ages who were examined in Craniocaudal (CC) and Mediolateral oblique (MLO) positions for both sides of breasts ( 2,960 images ). The ages of the patients, the compressed breast thickness and the absorbed doses of breasts were collected for analysis.
Results: The mean age of the patients was 48.2 ± 4.6 years.The average absorbed dose of breasts (with grid), in overall, was 2 milligrays per image with the average compressed breast thickness, inoverall, 5.1 centimetres. The amout that the absorbed doses of breasts (with grid) below 3milligrays was 95.1 %. There were 146 images (4.9%) that the absorbed doses of breasts (with grid) were above 3milligrays with the average compressed breast thickness at 5.5± 0.0 centimetres which was significant higher than the group that the average absorbed doses of breasts (with grid) below 3 milligrays(p-value < 0.001).
Conclusion: The average absorbed dose of breasts in digital mammography at Surin Hospital was within the standard level. There were 95.1 % that the absorbed doses of breasts (with grid) below 3 milligrays