量化直立患者体位对心脏亚结构影响的深度学习研究

中文摘要 AI 辅助

直立式患者定位装置在治疗等中心处提供诊断质量的垂直CT，可能改善图像引导放射治疗（RT）。然而，直立患者的心脏亚结构（CS）几何形状仍未得到充分表征。本研究评估了基于仰卧位训练的深度学习（DL）CS分割模型是否可泛化至直立CT图像，并量化胸部患者中依赖体位的CS变化，以评估潜在的CS保护获益。8名胸部质子治疗患者接受了配对仰卧位/直立位4DCT成像。在两个数据集上手动标注了20个CS和肺以进行位置比较。先前开发的基于仰卧位训练的DL流程生成了相同的CS，并使用Dice相似系数（DSC）和95%豪斯多夫距离（HD95）评估性能。通过对齐胸椎将直立CT刚性配准至相应的仰卧位CT，并在配准坐标系中及相对于隆突测量CS质心位移。使用Wilcoxon符号秩检验（p<0.05）评估配对差异。DL模型成功预测了直立位（DSC，0.65(0.24)；HD95，7.6(5.6)mm）和仰卧位（DSC，0.72(0.19)；HD95，5.8(2.6)mm）图像上的所有20个CS，但直立位性能较低（p<0.05）。直立定位显著增加了中位肺体积20.6%（范围，-8.9%-42.8%）。椎体对齐后，大多数CS质心在直立位时显著向下（中位心脏位移，23mm；范围，18-37mm）和向前（中位心脏位移，5.0mm；范围，1.0-13.0mm）移动。相对于隆突，大多数CS显著向下并更靠近前后方向移动。基于仰卧位训练的DL模型可泛化至直立CT图像的CS分割。直立定位产生增加的肺体积和显著的CS向下位移，表明可能支持心脏保护工作流程的有利几何变化。

英文摘要

Upright patient positioners with diagnostic-quality vertical CT at treatment isocenter may improve image-guided radiation therapy (RT). However, cardiac substructure (CS) geometry in upright patients remains insufficiently characterized. This work evaluated if a supine-trained deep-learning (DL) CS segmentation model generalizes to upright CT images and quantified posture-dependent CS changes in thoracic patients, to assess potential CS-sparing benefits. 8 thoracic proton therapy patients underwent paired supine/upright 4DCT imaging. 20 CS and lungs were manually labeled on both datasets for positional comparisons. A previously developed supine-trained, DL pipeline generated the same CS, and performance was evaluated using Dice similarity coefficient (DSC) and 95% Hausdorff distance (HD95). Upright CTs were rigidly registered to corresponding supine CTs by aligning the thoracic vertebrae, and CS centroid shifts were measured in the registered coordinate frame and relative to the carina. Paired differences were assessed using Wilcoxon signed-rank tests (p<0.05). The DL model successfully predicted all 20 CS on both upright (DSC, 0.65(0.24); HD95, 7.6(5.6)mm) and supine (DSC, 0.72(0.19); HD95, 5.8(2.6)mm) images yet with lower (p<0.05) performance upright. Upright positioning significantly increased median lung volume by 20.6% (range, -8.9%-42.8%). After vertebral alignment, most CS centroids shifted significantly inferior (median heart shift, 23mm; range, 18-37mm) and anterior (median heart shift, 5.0mm; range, 1.0-13.0mm) when upright. Relative to the carina, most CS shifted significantly inferior and closer anterior-posterior. A supine-trained DL model generalized to upright CT images for CS segmentation. Upright positioning produced increased lung volumes and significant inferior CS displacement, suggesting favorable geometry changes that may support cardiac-sparing workflows.

发表机构

• University of Wisconsin-Madison（威斯康星大学麦迪逊分校）
• Northwestern Medicine Proton Center（西北医学质子中心）
• Leo Cancer Care, Inc.（Leo癌症护理公司）

机构由 AI 辅助整理，请以论文原文为准。