iSCOUT图像引导定位技术在肺癌调强放疗中的临床应用

Clinical application of iSCOUT image guided position technology in intensity modulated radiation therapy for lung cancer

目的探讨iSCOUT图像引导定位技术在肺癌调强放疗中应用价值。方法选择75例接受调强治疗的肺癌患者,在进行首次放疗时,在摆位后放疗前对其先行CBCT扫描,再行iSCOUT扫描。将两组扫描的影像和CT定位重建的DRR影像进行配准,从而分别计算出摆位误差。结果在RL、SI和AP方向的摆位误差对比中,CBCT组与iSCOUT组差异无统计学意义(P=0.64、0.25、0.35);在RL、SI和AP方向的摆位误差一致性对比中,两组具有高度的一致性(k=0.80、0.74、0.90);CBCT组的准备时间占优(t=-47.38,P<0.05),iSCOUT组的曝光时间、配准时间和定位总时间占优(t=559.49,P<0.05;t=13.69,P<0.05;t=73.99,P<0.05)。结论肺癌调强放疗时,采用iSCOUT图像引导定位技术计算的摆位误差十分接近CBCT在线校正技术,对于没有装配CBCT扫描的直线加速器,iSCOUT扫描是一种值得推荐的图像引导定位技术,iSCOUT图像引导定位技术可以缩短定位时间,降低患者受照剂量,降低摆位误差,提高放疗效果。

Objective The aim of this study is to investigate the application value of iSCOUT image-guided position technology in intensity-modulated radiotherapy for lung cancer. Methods Seventy-five patients with lung cancer who received intensity-modulated therapy were participated in this study. When receiving radiotherapy on first time,the patients received CBCT scan then iSCOUT scan before placement. Two groups of scanned images and DRR images reconstructed by CT positioning were registered to calculate the positioning errors respectively. Results There was no significant difference between CBCT group and iSCOUT group in the placement errors of RL,SI,and AP directions(P = 0.64,0.25,0.35);the two groups had high consistency in the placement errors of RL,SI and AP directions(k = 0.79,0.69,0.88);the preparation time of CBCT group was superior(t =-47.38,P < 0.05)and the exposure time of iSCOUT group was superior. Interval,registration time and total location time were dominant(t = 559.49,P < 0.05;t = 13.69,P < 0.05;t = 73.99,P < 0.05). Conclusion The setup error calculated by iSCOUT image-guided localization technology in intensity-modulated radiotherapy for lung cancer was very close to that of CBCT on-line correction technology. For linear accelerators without CBCT scanning,iSCOUT scanning was a recommended image-guided localization technology. iSCOUT image-guided position technology could greatly shorten the positioning time,reduce the patient′ s irradiated dose,reduce the positioning error and improve the effect of radiotherapy.