Manchester Cancer Research Centre, Division of Molecular and Clinical Cancer Science, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Sciences Centre, UK; The Christie NHS Foundation Trust, Manchester Academic Health Sciences Centre, Manchester, UK.
Manchester Cancer Research Centre, Division of Molecular and Clinical Cancer Science, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Sciences Centre, UK; The Christie NHS Foundation Trust, Manchester Academic Health Sciences Centre, Manchester, UK.
Int J Radiat Oncol Biol Phys. 2018 Oct 1;102(2):434-442. doi: 10.1016/j.ijrobp.2018.05.052. Epub 2018 Jun 1.
Image guided radiation therapy (IGRT) is widely used, but data directly relating set-up errors to patient outcome are scarce. This study investigates the relationship between residual IGRT shifts and overall patient survival and uses the observed relations to identify structures sensitive to radiation dose.
Residual shift data for 780 patients with non-small cell lung cancer were summarized for each patient over the course of treatment by determining the mean shifts, standard deviations, and the vector shift in the direction of the heart. These variables were related to overall survival, and significant variables were used to produce Kaplan-Meier plots of survival. The effect of shift directionality was studied by splitting the cohort into left, right, anterior, posterior, superior, and inferior groups and by analyzing the vector shift in the direction of the heart. The observed relationship was independently validated in an esophageal cancer cohort (n = 177).
The shift data showed strong associations with survival. Left and right cohorts showed opposite directional shift effects, suggesting shifts toward the mediastinum have a negative effect on survival. Projection of the vector shift in the direction of the heart showed that patients with a residual shift toward the heart have significantly worse overall survival (P = .007, hazard ratio 1.091). The same effect was observed in the esophageal cancer cohort (P = .041, hazard ratio 1.164).
Residual shift metrics derived from IGRT data can categorize patients with non-small cell lung cancer and those with esophageal cancer into populations with significantly different survival times on the basis of the size of the residual shift in the direction of the heart, thus providing evidence of the importance of using strict IGRT protocols to spare organs at risk and highlighting the heart as a dose-sensitive organ.
图像引导放射治疗（IGRT）被广泛应用，但将摆位误差与患者预后直接相关的数据却很少。本研究调查了残余 IGRT 移位与总体患者生存之间的关系，并利用观察到的关系来确定对辐射剂量敏感的结构。
通过确定每个患者在治疗过程中的平均移位、标准差和向心脏方向的矢量移位，总结了 780 例非小细胞肺癌患者的残余移位数据。这些变量与总生存率相关，有显著意义的变量用于生成生存的 Kaplan-Meier 图。通过将队列分为左侧、右侧、前侧、后侧、上侧和下侧组，并分析向心脏方向的矢量移位，研究了移位方向的影响。观察到的关系在食管癌队列（n = 177）中进行了独立验证。
移位数据与生存有很强的关联。左侧和右侧队列显示出相反的方向移位效应，表明向纵隔移位对生存有负面影响。向心脏方向投影的矢量移位表明，残余向心脏移位的患者总生存率明显较差（P =.007，风险比 1.091）。在食管癌队列中也观察到了同样的效果（P =.041，风险比 1.164）。
从 IGRT 数据中得出的残余移位指标可以根据向心脏方向的残余移位大小，将非小细胞肺癌患者和食管癌患者分为生存时间明显不同的人群，从而为使用严格的 IGRT 方案来保护危险器官的重要性提供证据，并强调心脏是一个对剂量敏感的器官。
