摘要
目的:比较局部晚期食管癌三维适形放疗中二次CT定位靶区中心位置的变动。方法:对患者进行体部热塑膜、真空垫固定,治疗体位下分别于放疗开始时及放疗中(原发病灶剂量DT40Gy)进行2次CT模拟定位、影像传输、用治疗计划系统勾画GTV、PTV,制定三维放疗计划,PTV以90%等剂量线包绕靶区,根据两次靶区中心位置确认X轴、Y轴、Z轴的移动范围,判断靶区中心位置的变动情况。结果:对于每位食管癌患者,放疗过程中,食管靶区位置均有不同程度的变动。Y轴变动幅度明显大于X轴的变动。结论:食管癌放疗剂量达40Gy时需进行第二次CT定位。
Objective：To study the isocenter shifts between two phased CT scans during 3 - dimensional conformal radiotherapy for locally advanced esophageal carcinoma. Methods：Patients were superiorly laid immobilized with thermoplastic cast and vacuum pillow. Two CT series were scanned before RT and 40Gy post RT respectively, the CTV and PTV were accordingly delineated on the planning system, the two coordinate isocenters were therefore recorded and compared with their respective shifts along X, Y, and Z axis. Results ： A definitive range of shifting of the isocenter along 3 axes was observed with most evident changes in the Y axis. Conclusion：The second localization CT scan after irradiation of 40Gy is warranted for the radiotherapy of the advanced esopharyngeal carcinoma.
出处
《现代肿瘤医学》
CAS
2009年第9期1699-1700,共2页
Journal of Modern Oncology
