Young K C, Burch A
Medical Physics Department, Royal Surrey County Hospital, Guildford, UK.
Br J Radiol. 2000 Mar;73(867):278-87. doi: 10.1259/bjr.73.867.10817044.
The mean glandular doses (MGDs) to samples of women attending for mammographic screening are measured routinely at screening centres in the UK Breast Screening Programme (NHSBSP). This paper reviews the data collected during screening in the NHSBSP in 1997 and 1998 for 23,752 films, using 171 X-ray sets, for 8745 women. Average MGD was 2.03 mGy per oblique film and 1.65 mGy per craniocaudal film, similar to the MGDs found previously in the NHSBSP for the years 1994 and 1995. MGD was found to increase with compressed breast thickness where the tube potential was selected manually, so that the average dose for 10 cm thick breasts was 2.7 times the average for all breasts. For large breasts (> 70 mm) the use of X-ray sets such as the IGE DMR, which automatically select the beam quality for each breast, resulted in lower doses compared with sets using manual tube potential selection. MGD to the standard breast was found to vary from 0.7 to 2.2 mGy and to be correlated with the average MGD per mediolateral oblique film for the women screened on that system (R = 0.79). No correlation between age and MGD was found within the invited age range of 50-64 years.
在英国乳腺筛查项目（NHSBSP）的筛查中心，会定期测量参加乳腺钼靶筛查的女性样本所接受的平均腺体剂量（MGD）。本文回顾了1997年和1998年NHSBSP筛查期间收集的数据，这些数据涉及使用171台X光机为8745名女性拍摄的23752张胶片。平均MGD为每张斜位片2.03毫戈瑞，每张头尾位片1.65毫戈瑞，与NHSBSP此前在1994年和1995年发现的MGD相似。研究发现，在手动选择管电压的情况下，MGD会随着乳房压缩厚度的增加而增加，因此10厘米厚乳房的平均剂量是所有乳房平均剂量的2.7倍。对于大乳房（>70毫米），使用如IGE DMR等能自动为每个乳房选择射线质的X光机，与使用手动管电压选择的设备相比，剂量更低。标准乳房的MGD在0.7至2.2毫戈瑞之间变化，并且与在该系统上接受筛查的女性的每侧斜位片平均MGD相关（R = 0.79）。在50 - 64岁的受邀年龄范围内，未发现年龄与MGD之间存在相关性。
