Model-based cardiac dose estimation in radiation treatment of left breast cancer
Model-based cardiac dose estimation in radiation treatment of left breast cancer
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DOI：
10.1259/bjr.20180287
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发表时间：
2018-01-01
影响因子：
2.6
通讯作者：
Das, Indra J.
中科院分区：
文献类型：
--
作者：
Ueda, Yoshihiro;Gerber, Naamit K.;Das, Indra J.
目的：为了开发一个数学模型，心脏剂量估计的患者谁已经接受了治疗左侧乳腺癌没有CT data.Methods：获得机构审查委员会批准后，147例左侧乳腺癌患者被选中，仰卧位治疗，反对切线。从切向野中去除心脏块，并使用高级算法使用6 MV射束进行剂量计算。本研究使用DRR的CT数据进行，以代表过去治疗的放射学模拟图像。创建了显示勾画的乳房、肺和心脏的波束眼视图图像，以代表X线片上的视图。记录最大心距（MHD），用三角形和矩形组合法计算照射心脏面积（AREA）。在精确计算三维剂量的基础上，采用线性拟合和二次拟合的方法，分析了心脏平均剂量（Dmean）和V-10 ~ V-50与MHD和AREA的剂量学参数之间的关系。MHD和AREA与Dmean、V-10、V-20、V-30和V-50的线性模型相关性非常好（R-2 > 0.91），而二次模型相关性显著更好（R-2 > 0.92）。与我们的线性和二次模型的剂量测定误差的分析是显着的误差< 3%的cases.Conclusion：建议的数学模型的心脏剂量估计是准确的+/- 3%内使用X光片没有CT数据。这为将来与辐射剂量和心脏毒性相关的研究中的患者汇集提供了途径。这些结果将有助于准确地估计心脏剂量分析，从以前的研究，以及在中心仍然使用2D planning.Advances in Knowledge：证据表明，心脏风险放疗后仍然是一个重要的考虑因素，为左侧乳腺癌患者的管理。剂量-风险效应估计中的一个问题是CT前治疗的心脏剂量重建。在这项研究中，提出了一个简单的数学模型，可以估计左乳腺癌的心脏剂量在+/-3%以内
Objective: To develop a mathematical model for cardiac dose estimation for patients who have been treated for left-sided breast cancer without CT data.Methods: After obtaining institutional review board approvals, 147 patients with left-sided breast cancer were selected that were treated supine with opposed tangents. The heart blocks from the tangential fields were removed and dose calculations were performed with 6 MV beams using an advanced algorithm. This study was performed with CT data with DRR to represent a radiographic simulator image of yesteryear treatments. The beam's eye-view images showing delineated breast, lung and heart were created to represent views on radiograph. The maximum heart distance (MHD) was recorded and irradiated heart area (AREA) was computed by combination of triangles and rectangles. Based on accurate 3D dose calculation, mean dose (Dmean) and V-10 to V-50 of heart were analyzed with respect to MHD and AREA for dosimetric parameters using linear and quadratic fit.Results: The treatment parameters calculated by MHD and segments using 2D radiographs were within 2% of the actual dosimetric parameters computed from the 3D planning system. The MHD and AREA vs Dmean, V-10, V-20, V-30 and V-50 showed very good correlation with linear model (R-2 > 0.91); however the correlation was significantly better with quadratic model (R-2 > 0.92). The analysis of the dosimetric error with our linear and quadratic model is remarkable within < 3% error for most cases.Conclusion: The proposed mathematical model for the cardiac dose estimation is accurate within +/- 3% using a radiograph without CT data. This provides avenues for patient pooling in future studies related to radiation dose and cardiac toxicity. These results will help in estimating cardiac dose analysis accurately from previous studies as well as in centers still using 2D planning.Advances in Knowledge: The evidence of cardiac risk following radiotherapy continues to be one of the important considerations for the management of left-sided breast cancer patients. One of the problem in the estimation of dose-risk effects is the reconstruction of heart dose for pre-CT treatments. In this study, a simple mathematical model is presented that could estimate cardiac dose within +/- 3% in left breast cancer