Dhou Salam, Dalah Entesar, AlGhafeer Reda, Hamidu Aisha, Obaideen Abdulmunhem
Department of Computer Science and Engineering, American University of Sharjah, Sharjah P.O. Box 26666, United Arab Emirates.
Biomedical Engineering Graduate Program, American University of Sharjah, Sharjah P.O. Box 26666, United Arab Emirates.
J Imaging. 2022 Jul 31;8(8):211. doi: 10.3390/jimaging8080211.
Breast cancer is the leading cause of cancer death among women worldwide. Screening mammography is considered the primary imaging modality for the early detection of breast cancer. The radiation dose from mammography increases the patients' risk of radiation-induced cancer. The mean glandular dose (MGD), or the average glandular dose (AGD), provides an estimate of the absorbed dose of radiation by the glandular tissues of a breast. In this paper, MGD is estimated for the craniocaudal (CC) and mediolateral-oblique (MLO) views using entrance skin dose (ESD), X-ray spectrum information, patient age, breast glandularity, and breast thickness. Moreover, a regression analysis is performed to evaluate the impact of mammography acquisition parameters, age, and breast thickness on the estimated MGD and other machine-produced dose quantities, namely, ESD and organ dose (OD). Furthermore, a correlation study is conducted to evaluate the correlation between the ESD and OD, and the estimated MGD per image view. This retrospective study was applied to a dataset of 2035 mammograms corresponding to a cohort of 486 subjects with an age range of 28-86 years who underwent screening mammography examinations. Linear regression metrics were calculated to evaluate the strength of the correlations. The mean (and range) MGD for the CC view was 0.832 (0.110-3.491) mGy and for the MLO view was 0.995 (0.256-2.949) mGy. All the mammography dose quantities strongly correlated with tube exposure (mAs): ESD (R = 0.938 for the CC view and R = 0.945 for the MLO view), OD (R = 0.969 for the CC view and R = 0.983 for the MLO view), and MGD (R = 0.980 for the CC view and R = 0.972 for the MLO view). Breast thickness showed a better correlation with all the mammography dose quantities than patient age, which showed a poor correlation. Moreover, a strong correlation was found between the calculated MGD and both the ESD (R = 0.929 for the CC view and R = 0.914 for the MLO view) and OD (R = 0.971 for the CC view and R = 0.972 for the MLO view). Furthermore, it was found that the MLO scan views yield a slightly higher dose compared to CC scan views. It was also found that the glandular absorbed dose is more dependent on glandularity than size. Despite being more reflective of the dose absorbed by the glandular tissue than OD and ESD, MGD is considered labor-intensive and time-consuming to estimate.
乳腺癌是全球女性癌症死亡的主要原因。乳腺钼靶筛查被认为是早期发现乳腺癌的主要影像学检查方法。乳腺钼靶的辐射剂量会增加患者患辐射诱发癌症的风险。平均腺体剂量（MGD），即平均腺剂量（AGD），可估算乳腺腺体组织吸收的辐射剂量。本文利用入射皮肤剂量（ESD）、X射线光谱信息、患者年龄、乳腺腺体密度和乳腺厚度，对头尾位（CC）和内外斜位（MLO）投照的MGD进行估算。此外，进行回归分析以评估乳腺钼靶采集参数、年龄和乳腺厚度对估算的MGD以及其他机器产生的剂量参数（即ESD和器官剂量（OD））的影响。此外，开展相关性研究以评估ESD与OD之间以及每个投照视图估算的MGD之间的相关性。这项回顾性研究应用于2035份乳腺钼靶检查数据集，该数据集对应486名年龄在28 - 86岁之间接受乳腺钼靶筛查的受试者队列。计算线性回归指标以评估相关性强度。CC投照的平均（及范围）MGD为0.832（0.110 - 3.491）mGy，MLO投照的为0.995（0.256 - 2.949）mGy。所有乳腺钼靶剂量参数与管电流 - 时间乘积（mAs）均高度相关：ESD（CC投照R = 0.938，MLO投照R = 0.945）、OD（CC投照R = 0.969，MLO投照R = 0.983）和MGD（CC投照R = 0.980，MLO投照R = 0.972）。与患者年龄相比，乳腺厚度与所有乳腺钼靶剂量参数的相关性更好，患者年龄的相关性较差。此外，计算得到的MGD与ESD（CC投照R = 0.929，MLO投照R = 0.914）和OD（CC投照R = 0.971，MLO投照R = 0.972）均高度相关。此外，发现MLO扫描视图产生的剂量略高于CC扫描视图。还发现腺体吸收剂量对腺体密度的依赖性大于对大小的依赖性。尽管MGD比OD和ESD更能反映腺体组织吸收的剂量，但估算MGD被认为是劳动强度大且耗时的。
