摘要
目的用三维适形治疗计划系统分析食管癌传统放疗及三维适形放疗中肿瘤和周围组织器官的剂量分布。方法对44例首程放疗中晚期食管癌患者常规透视下模拟定位,确定病变中心和最佳入射角度,金属标记物标记前垂直野中心及野框后行CT模拟定位。CT扫描图像经局域网传输到治疗计划系统(CMSFocus3.0或ADACPinnacle6.2b)进行三维重建,由主管医师勾画大体肿瘤体积(GTV)、临床靶体积(CTV)和危及器官。物理师为每例患者设计3套治疗计划:即常规治疗计划、三维适形治疗计划和虚拟常规治疗计划。结果(1)食管造影所示病变平均长度5.42cm,CT扫描平均长度8.42cm(P=0.000)。CT扫描肿瘤最大左右径平均5.48cm,GTV平均体积59.68cm3。常规模拟定位中心与三维适形治疗计划中心在X、Y、Z轴上分别相差7.67、13.21、7.68mm,两种定位方法的病变中心在X轴上的差异有统计学意义(P=0.001);(2)全组中位处方剂量6600cGy。常规治疗计划、虚拟常规治疗计划、三维适形治疗计划的GTV100%体积剂量分别为3406.8、6379.1、6290.0cGy;GTV95%体积剂量分别为4344.1、6484.7、6453.6cGy,CTV95%体积剂量分别为3303.0、6375.3、6081.8cGy;PTV95%体积剂量分别为1739.4、6035.9、5243.9cGy。可见三维适形治疗计划的GTV、CTV及PTV100%、95%体积剂量均高于常规计划。结论三维适形放疗技术能够给予肿瘤靶区均匀的剂量分布,并使其周围正常组织得到保护。
Objective To assess the dose distribution by three dimensional conformal treatment planning system （TPS） for the primary lesion and normal tissues around esophagus carcinoma in contrast to conventional radiotherapy. Methods Forty-four patients with untreated esophageal carcinoma were studied before treatment. They were first immobilized and simulated conventionally under the simulator in the treatment position. The field centers, gantries and collimators were noted and marked by barium meal while being simulated. And then , they were scanned by CT simulator in the same position. The images were transferred through local network to the treatment planning system （ CMS Focus 3.0 or ADAC Pinnacle 6.2b） and reconstructed by TPS. Gross tumor volume （GTV）,clinical target volume （CTV） and organs at risk were outlined. Three treatment plans were designed for each patient： 1. Conventional treatment plan（CTP） ;2. Three dimensional conformal radiotherapy plan （CRT） ; and 3.Virtual conventional treatment plan （VCTP）. Results 1. The average length of lesion was 5.42 cm on esophageal barium meal and 8.42 cm on CT scan, with a significant difference between the two methods （ P = 0.000）. The greatest diameter of tumor was 5.48 cm on CT scan. The average volume of GTV was 59.68 cm^3. The deviation of field center along X, Y, Z axis was 7.67, 13.21, 7.68 mm, of which there was a significant difference in the X axis（ P =0.001）; 2.With the a median prescription dose of 6600 cGy for each patient, the dose of 100% GTV volume was 3406.8,6379.1 and 6290.0 cGy for CTP, VCTP and CRT, respectively. The dose of 95% GTV volume was 4344.1, 6484.7 and 6453.6 cGy, respectively . The dose of 95% CTV volume was 3303.0, 6375.3 and 6081.8 cGy, respectively. And the dose of 95% PTV volume was 1739.4,6035.9 and 5243.9 cGy, respectively. Our results showed that the dose of 100%, 95% volume of GTV, CTV and PTV of CRT were significantly higher than that of CPT. Coonclusions Three dimensional conformal radiotherapy can well achieve ideal dose distribution and coverage over the target volume and well protect the normal tissues around the esophagus carcinoma at the same time.
出处
《中华放射肿瘤学杂志》
CSCD
北大核心
2006年第3期176-180,共5页
Chinese Journal of Radiation Oncology
关键词
食管肿瘤/放射疗法
治疗计划系统
放射治疗剂量
Esophageal neoplasms/radiotherapy
Treatment planning system
Radiotherapy dosage
