目的：研究螺旋断层放疗（HT）中肝脏肿瘤患者的呼吸运动影响以及影像引导下影像配准的临床价值。方法随机选取36例接受HT治疗的肝脏肿瘤患者，在平静浅呼吸状态下行MVCT扫描并与治疗计划系统（TPS）数字重建影像（DRR）进行两次配准（分别以肝脏和肝区病变，以及骨性标志物和非运动型软组织为参考进行配准），获取患者的呼吸动度信息，分析配准原则及方法。结果36例病人共进行MVCT扫描768次，呼吸相位差异在X（左右）方向上全组平均值为，个体最大值为6.60 mm；Y（头脚）方向上全组平均值为（10.64±2.34）mm，个体最大值为26.70 mm；Z（前后）方向上全组平均值为（4.57±0.90）mm，个体最大值为11.30 mm；患者间呼吸相位差异在各方向上均无统计学意义。结论肝脏肿瘤患者影像配准受呼吸运动影响较大，在摆位时应对病人进行呼吸训练，以减少呼吸运动对肝脏肿瘤放疗的影响；同时，配准应以骨性及其他非运动型软组织标志物为参考，当配准差值大于靶区外放范围时，应考虑重新对患者进行呼吸训练以及影像配准。%Objective To analyze the clinical effectiveness of the respiratory movement in liver carcinoma patients by using the image guidance in HT (Helical Tomotherapy) with MVCT (Mega-Voltage Computerized Tomography).Methods Altogether 36 patients with primary or metastatic liver cancers were randomly selected and then underwent MVCT scans in the calm and shallow breathing state and DDR (Digital Reconstruction Radiograph) registration in the TPS (Treatment Planning Systems) twice, respectively taking the liver and liver lesions as well as the osseous markers and non-movement soft tissue as the references for registration, so as to acquire the respiratory mobility information of patients and analyze the registration principle and method.Results All the 36 patients were scanned by using MVCT for 768 times. The average phase error of respiratory mobility for all the patients in X, Y and Z were (3.05±0.5) mm (max for individual patients: 6.60 mm), (10.64±2.34) mm (max for individual patients: 26.70 mm) and (4.57±0.90) mm (max for individual patients: 11.30 mm), respectively, without statistically signiifcant differences.Conclusion Liver cancer patients were greatly affected by respiratory movement registration errors. The respiratory training was necessary for patients in placement, in order to reduce the inlfuence of respiratory movement on liver tumor radiotherapy. Meanwhile, the osseous markers and non-movement soft tissue shall be taken as the reference for registration. In case that the registration error > the range of target area, respiratory training and imaging registration should be considered for patients again.
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