Waade Gunvor G, Sanderud Audun, Hofvind Solveig
Department of Life Sciences and Health, Faculty of Health Sciences, Oslo and Akershus University College of Applied Sciences, P.O. 4 St. Olavs Plass, 0130 Oslo, Norway.
Department of Life Sciences and Health, Faculty of Health Sciences, Oslo and Akershus University College of Applied Sciences, P.O. 4 St. Olavs Plass, 0130 Oslo, Norway; The Cancer Registry of Norway, P.O. 5313 Majorstuen, 0304 Oslo, Norway.
Eur J Radiol. 2017 Mar;88:41-46. doi: 10.1016/j.ejrad.2016.12.025. Epub 2016 Dec 31.
Compression force is used in mammography to reduce breast thickness and by that decrease radiation dose and improve image quality. There are no evidence-based recommendations regarding the optimal compression force. We analyzed compression force and radiation dose between screening centers in the Norwegian Breast Cancer Screening Program (NBCSP), as a first step towards establishing evidence-based recommendations for compression force.
The study included information from 17 951 randomly selected screening examinations among women screened with equipment from four different venors at fourteen breast centers in the NBCSP, January-March 2014. We analyzed the applied compression force and radiation dose used on craniocaudal (CC) and mediolateral-oblique (MLO) view on left breast, by breast centers and vendors.
Mean compression force used in the screening program was 116N (CC: 108N, MLO: 125N). The maximum difference in mean compression force between the centers was 63N for CC and 57N for MLO. Mean radiation dose for each image was 1.09mGy (CC: 1.04mGy, MLO: 1.14mGy), varying from 0.55mGy to 1.31mGy between the centers. Compression force alone had a negligible impact on radiation dose (r=0.8%, p=<0.001).
We observed substantial variations in mean compression forces between the breast centers. Breast characteristics and differences in automated exposure control between vendors might explain the low association between compression force and radiation dose. Further knowledge about different automated exposure controls and the impact of compression force on dose and image quality is needed to establish individualised and evidence-based recommendations for compression force.
乳房X线摄影术中使用压迫力来减小乳房厚度，从而降低辐射剂量并提高图像质量。目前尚无关于最佳压迫力的循证建议。作为朝着制定压迫力循证建议迈出的第一步，我们分析了挪威乳腺癌筛查项目（NBCSP）各筛查中心的压迫力和辐射剂量。
本研究纳入了2014年1月至3月期间在NBCSP的14个乳腺中心，对使用来自四个不同供应商设备进行筛查的女性中随机选取的17951例筛查检查的信息。我们按乳腺中心和供应商分析了左乳头尾位（CC）和内外斜位（MLO）视图上施加的压迫力和辐射剂量。
筛查项目中使用的平均压迫力为116N（CC：108N，MLO：125N）。各中心之间平均压迫力的最大差异，CC位为63N，MLO位为57N。每张图像的平均辐射剂量为1.09mGy（CC：1.04mGy，MLO：1.14mGy），各中心之间从0.55mGy到1.31mGy不等。仅压迫力对辐射剂量的影响可忽略不计（r = 0.8%，p < 0.001）。
我们观察到各乳腺中心之间的平均压迫力存在显著差异。乳房特征以及供应商之间自动曝光控制的差异可能解释了压迫力与辐射剂量之间的低相关性。需要进一步了解不同的自动曝光控制以及压迫力对剂量和图像质量的影响，以制定针对压迫力的个性化和循证建议。
