肺部肿瘤射波刀治疗前模拟追踪结果研究

Study on the Simulation before the Treatment of Lung Cancer with Cy berknife Xsight Lung Tracking

目的:射波刀VSI治疗肺部肿瘤可采用同步呼吸肺追踪(Xsight lung)方法来提高治疗精确度,而治疗前需采用模拟追踪(simulation)程序来区分能否用肺部追踪方法追踪。研究通过记录患者肺部病灶位置、大小、CT值等差异,分析模拟追踪结果与以上各因素的相关性。方法:使用CT定位,选取吸气末和呼气末的图像并以此来制订模拟追踪计划。对患者完成模拟追踪计划,采用logistic回归分析计划靶区体积(PTV)、肿瘤最大直径、病灶位置等因素与成功进行肺追踪的相关性。结果:共纳入69例患者进行模拟追踪,24例患者未实现肺病灶追踪(仅脊柱追踪或单侧肺追踪),45例患者实现双侧肺追踪。logistic多因素回归分析结果显示,肿瘤直径大(OR=1.53,P=0.022)、肺部病灶位于上肺(OR=4.5,P=0.015)者,更容易得到双侧肺追踪扫描结果。结论:肿瘤直径越大、病灶位置位于上肺者更容易进行双侧肺追踪,从而可以在射波刀治疗期间使用Xsight lung追踪方法。

Purpose:The Xsight lung tracking method can be used to improve the accuracy of the lung cancer treatment during Cyberknife VSI therapy,and a simulation program is used to check if the Xsight lung method could be used before the treatment.In this study,we tried to analyze the correlation between the tracking results and the characteristic factors including tumor location,size,and CT value.Methods:The end-inspiratory CT images and end-expiratory CT images were used to create the simulation plan.After completing the simulation tracking plan,variables of the planning target volume(PTV),maximum tumor diameter,lesion location,and other factors were included to detect the relevance of the Xsight lung tracking result using multiple logistic regression analysis.Results:Sixty-nine patients were included in the Xsight lung tracking simulation.A total of 24 patients who had spine tracking and unilateral lung tracking were defined as not eligible to have Xsight lung tracking.Forty-five patients were able to undergoing Xsight lung tracking.Logistic multivariate analysis showed that factors including larger tumor diameter(OR=1.53,P=0.022),and lesions in the upper lung(OR=4.5,P-0.015)were correlated with the results of Xsight lung tracking.Conclusion:Patients with a larger tumor diameter and upper lung tumor lesions are more likely to have Xsight lung tracking result during Cyberknife treatment.