摘要
目的 探讨锥形束CT(CBCT)对非小细胞肺癌(NCSLC)患者体部立体定向放疗法(SBRT)中图像引导准确性、摆位误差的影响.方法 选取我院收治的NCSLC患者97例,均行SBRT治疗.研究对象均行CBCT采集图像.于SBRT治疗前行CBCT扫描,扫描获取图像和计划CT图像匹配,获取Y轴、X轴、Z轴线性误差,探讨误差与其分布规律、误差对放疗剂量分布影响.结果 X轴是(-0.4±2.62)mm,Y轴是(1.41±5.26)mm,Z轴是(-0.82±2.32)mm;X轴、Y轴、Z轴摆位误差区间≤3 mm的发生率明显高于其他摆位误差区间(P<0.05);首次扫描、其他各次扫描的X轴、Y轴、Z轴之间对比,P<0.05;模拟未移床V5、V10、V20、V30、Dmax以及Dmean为原计划(102.42±5.33)%、(104.11±6.41)%、(106.40±13.42)%、(110.25±39.04)%、(98.22±6.720)%、(92.33±5.67)%、(88.13±9.39)%、(98.75±5.11)%;PTV D95与原计划对比,P<0.05.结论 CBCT可纠正接受SBRT治疗NCSLC患者摆位误差,减少正常组织、靶区射线受量.
Abstract
Objective To explore the effect of conical beam CT(CBCT)on image guidance accuracy and placement errors in stereotactic radiotherapy(SBRT)for patients with non-small cell lung cancer(NCSLC).Methods A total of 97 NCSLC patients admitted to our hospital were selected and received SBRT treatment.All subjects received CBCT images.Before SBRT treatment,CBCT scan was performed to match the obtained images with the planned CT images,to obtain the errors of Y axis,X axis and Z axis,and to explore the errors and their distribution rules,as well as the influence of errors on radiotherapy dosage distribution.Results The measurement errors were as follows:X axis was(-0.4±2.62)mm,Y axis was(1.41±5.26)mm,Z axis was(-0.82±2.32)mm.The incidence of X axis,Y axis and Z axis positioning error interval≤3mm was significantly higher than other positioning error interval(P<0.05).The difference between X axis,Y axis and Z axis of the first scan and other scans was statistically significant(P<0.05).Compared to the planned CT images,the simulated unmoved bed V5,V10,V20,V30,Dmax and Dmean were(102.42±5.33)%,(104.11±6.41)%,(106.40±13.42)%,(110.25±39.04)%,(98.22±6.720)%,(92.33±5).67)%,(88.13±9.39)%,(98.75±5.11)%.The difference between PTV D95 and the planned CT images was statistically significant(P<0.05).Conclusion CBCT can correct the positioning error of patients receiving SBRT treatment for NCSLC,and reduce the radiation exposure of normal tissue and target area.
维普
万方数据