基于4D-CT图像在肺癌放疗靶区勾画设计中的应用

Application of lung cancer in the delineating of the gross tumor target volumes based on 4D-CT image

目的探讨4D-CT图像在肺癌适形放疗靶区勾画中的应用价值。方法分别对8例肺癌患者行多层CT电影(Cine)和常规增强扫描,记录扫描参数信息。将扫描数据输入自主开发的4D-CT图像重建系统,进行4D-CT图像和MIP图像重建。模拟勾画4D适形精确放疗靶区;对同组8例患者常规扫描数据行3D传统放疗计划靶区设计。结果 8例肺癌患者4D-CT重建图像靶区勾画的GTV4D平均为:23.62±6.28cm3;该组患者的传统三维重建图像的GTV3D平均为:28.88±7.93cm3。结论传统3D的靶区设计因须考虑吸气和呼气末相的肿瘤位置而使GTV3D要大得多;采用4D-CT图像制定的适形放疗计划,大幅缩小了肿瘤靶区体积,降低了正常组织的受照剂量,可望减少中远期放疗并发症,提高放疗后生存质量。

【Objective】 To evaluate the clinical value of 16 slices 4D-CT in drawing target area of lung cancer conformal radiotherapy.【Methods】 8 lung cancer patients underwent cine mode CT scan and routine contrast-enhanced CT scan.Recorded the scan parameter and draw motion curve of up and down and side thorax scan the largest diameter fluctuated with the respiratory.The Cine scan CT datas were input into 4D-CT reconstruction system developed in house to create maximum intensity projection（MIP） CT.The 4D target volume based on MIP CT data and 3D conformal target volume in rutine CT were segmented seperately by using TPS.【Results】 The average valumn of GTV4D based on 4D-CT reconstruction images was 23.62±6.28cm3.The average GTV3D of conventional 3D restitution was 28.88±7.93cm3.【Conclusion】 The traditional 3D planning needs to consider the localization of the tumor at inspiration and expiration,so the average GTV3D was larger.The target area of tumor,the radiated area of normal tissue and radiotherapy complication were decreased and the tumour radiation dose,effective power and life quality were raised by using 4D-CT conformal radiotherapy plan.