Department of Radiology, School of Medicine, Makerere University, Kampala, Uganda.
Department of Microbiology and Immunology, Faculty of Medicine, Gulu University, Gulu, Uganda.
PLoS One. 2024 Aug 29;19(8):e0294541. doi: 10.1371/journal.pone.0294541. eCollection 2024.
Screening and diagnostic mammography are associated with some risk of radiation-induced breast cancer. This study was conducted to establish the National Diagnostic Reference Levels (NDRLs) for digital diagnostic and screening mammography in Uganda to achieve breast radiation dose optimization.
A cross-sectional study was conducted among female participants recruited by consecutive sampling from three selected hospitals with digital mammography in Uganda. The study variables extracted from the mammography machines were exposure factors, compressed breast thickness (CBT), and Average Glandular Dose (AGD) of two standard mammogram views. The stratified National DRL was derived by calculating the 75th percentile of the AGD across all the samples at various CBT ranges for both screening and diagnostic mammography in craniocaudal (CC) and mediolateral oblique (MLO) views.
We included 300 participants with mean ages of 50.28±9.32 and 47.45±13.45 years for the screening and diagnostic mammography, respectively. There were statistically significant positive correlations between AGD and exposure factors (mAs, kVp) (all p-values<0.0001). For screening mammography, mAs demonstrated a strong positive correlation (r = 0.8369 in CC, 0.8133 in MLO), whereas kVp showed a positive correlation with relatively lower coefficients (r = 0.3700 in CC, 0.3080 in MLO). For diagnostic mammography, mAs exhibited an even stronger positive correlation (r = 0.8987 in CC, 0.8762 in MLO), and kVp maintained a positive correlation with somewhat lower coefficients (r = 0.4954 in CC, 0.3597 in MLO). In screening mammography, for CBT within the range of (7-39) mm, the NDRLs were (1.5mGy, 1.66mGy) in CC) and MLO views. For CBT in the range of (40-59) mm, the NDRLs were (1.78mGy, 1.87mGy), and for CBT in the range of (60-99) mm, the NDRLs were (2.18mGy, 2.22mGy). For diagnostic mammography, the NDRLs were established as (1.7mGy, 1.91mGy), (2.00mGy, 2.09mGy), and (2.63mGy, 2.81mGy) for CBT ranges of (7-39) mm, (40-59) mm, and (60-99) mm, respectively.
The NDRLs for digital screening and diagnostic mammography in Uganda have been proposed for the first time. The NDRL values in mammography should be specific to CBT ranges and mammographic views for both diagnostic and screening mammography.
乳腺筛查和诊断性乳房 X 光摄影会带来一定的辐射诱导乳腺癌风险。本研究旨在建立乌干达数字诊断性和筛查性乳房 X 光摄影的国家诊断参考水平（NDRL），以实现乳房放射剂量优化。
本研究采用横断面研究，在乌干达的三家具有数字乳房 X 光摄影的选定医院中，通过连续抽样招募女性参与者。从乳房 X 光机中提取的研究变量包括曝光因素、压缩乳房厚度（CBT）和两种标准乳房 X 光摄影视图的平均腺体剂量（AGD）。通过在各种 CBT 范围内为筛查和诊断性乳房 X 光摄影在头尾（CC）和内外斜（MLO）视图计算所有样本的 AGD 的第 75 百分位数，得出分层的国家 DRL。
我们纳入了 300 名参与者，其平均年龄分别为 50.28±9.32 岁和 47.45±13.45 岁，用于筛查和诊断性乳房 X 光摄影。AGD 与暴露因素（mAs、kVp）之间存在显著的正相关（所有 p 值均<0.0001）。对于筛查性乳房 X 光摄影，mAs 表现出强烈的正相关（CC 中 r = 0.8369，MLO 中 r = 0.8133），而 kVp 则显示出与相对较低系数的正相关（CC 中 r = 0.3700，MLO 中 r = 0.3080）。对于诊断性乳房 X 光摄影，mAs 显示出更强的正相关（CC 中 r = 0.8987，MLO 中 r = 0.8762），kVp 保持与稍低系数的正相关（CC 中 r = 0.4954，MLO 中 r = 0.3597）。在筛查性乳房 X 光摄影中，对于 CBT 在（7-39）mm 范围内，CC 和 MLO 视图的 NDRL 分别为（1.5mGy、1.66mGy）。对于 CBT 在（40-59）mm 范围内，NDRL 分别为（1.78mGy、1.87mGy），对于 CBT 在（60-99）mm 范围内，NDRL 分别为（2.18mGy、2.22mGy）。对于诊断性乳房 X 光摄影，CBT 范围分别为（7-39）mm、（40-59）mm 和（60-99）mm 时，NDRL 分别为（1.7mGy、1.91mGy）、（2.00mGy、2.09mGy）和（2.63mGy、2.81mGy）。
首次提出了乌干达数字筛查和诊断性乳房 X 光摄影的国家诊断参考水平。乳房 X 光摄影的 NDRL 值应针对 CBT 范围和诊断性及筛查性乳房 X 光摄影的乳房 X 光视图进行具体设定。
