Introduction

Breast cancer treatments cause breast changes that are detectable in subsequent mammography exams. This work investigates if these changes are perceived as differences in breast composition by automatic exposure systems, and if such differences are high enough to have impact in exam doses.

Methods

Data was obtained for 226 patients treated with unilateral conservative surgery followed by radiotherapy (S&RT) of the left (114) or right (112) breast, who had mammographic exams in direct digital GE units, Senographe DS (SenoDS) or Senographe Essential (Essential). The relevant data was extracted from Digital Imaging and Communications in Medicine (DICOM) images, and the Mean Glandular Dose (MGD) was calculated using the model of Dance.

Results

Compression force and area were 15–30% lower for treated breasts (S&RT) relative to untreated, while compressed breast thickness (CBT), incident air kerma (Ki) and MGD were 14–17%, 22–28% and 10–18% higher, respectively. The variation of MGD and Ki with CBT is similar for treated and untreated breasts. High values of Ki, MGD and CBT occur for some treated breasts with relatively small areas, probably as a result of less compressible breast tissue. Equipment-determined composition was found to be similar for treated and untreated breasts.

Conclusion

Treated breasts are imaged with slightly higher doses as a result of higher CBT, but the dependence of Ki and MGD on CBT remains unchanged. There is no need to separate data for treated and untreated breasts in large-scale analysis of exam doses.

中文翻译：

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乳房 X 光检查中的辐射剂量：肿瘤治疗的效果

介绍

乳腺癌治疗会导致乳房发生变化，这些变化可以在随后的乳房 X 光检查中检测到。这项工作调查这些变化是否被自动曝光系统视为乳房成分的差异，以及这些差异是否足够高以影响检查剂量。

方法

获得了 226 名接受单侧保守手术治疗后接受左侧 (114) 或右侧 (112) 乳房放射治疗 (S&RT) 的患者的数据，这些患者在直接数字 GE 单位、Senographe DS (SenoDS) 或 Senographe Essential (Essential) 中进行了乳房 X 线摄影检查）。从医学数字成像和通信（DICOM）图像中提取相关数据，并使用舞蹈模型计算平均腺剂量（MGD）。

结果

与未治疗的乳房相比，经过治疗的乳房 (S&RT) 的压缩力和面积降低了 15-30%，而压缩的乳房厚度 (CBT)、入射空气比释动能 (Ki) 和 MGD 分别为 14-17%、22-28% 和 10-18 % 更高，分别。对于治疗和未治疗的乳房，MGD 和 Ki 与 CBT 的变化相似。Ki、MGD 和 CBT 的高值出现在一些面积相对较小的治疗乳房中，这可能是由于乳房组织的可压缩性较低。发现设备确定的成分对于治疗和未治疗的乳房是相似的。

结论

由于 CBT 较高，治疗过的乳房会以略高的剂量成像，但 Ki 和 MGD 对 CBT 的依赖性保持不变。在检查剂量的大规模分析中，无需分离治疗和未治疗乳房的数据。