摘要
目的 用三维治疗计划系统研究食管癌常规放射治疗中肿瘤和正常组织的剂量分布。方法 未经治疗的食管癌患者 2 0例经体位固定、模拟机定位、体膜上标记射野中心后进行CT扫描 ,通过局域网 (Lantis)将扫描图像传送到治疗计划系统 (CMSFocus)。由主任医生根据食管造影、纤维食管镜和CT勾画GTV、CTV和PTV。物理师为每例患者设计 3种野 :A为常规野 :以体膜上显示的标记点为模拟机定位中心 ,将模拟机定位的条件直接输入治疗计划系统 ;B为扩大野 ;C为适形野 :用三维治疗计划系统使靶区 (GTV、CTV和PTV)和正常组织达到满意剂量。结果 ( 1)CT扫描显示肿瘤的左右径平均为 4 .3cm ,前后径为 2 .9cm。常规模拟机定位中心与三维适形计划中心的位置在X、Y、Z轴方向上差 3.7、9.6、6 .4mm。 ( 2 )常规野和扩大野的处方剂量 (射野中心点的剂量 )为 6 0Gy ,分 30次 ,6周完成 ,其所覆盖的肿瘤体积占GTV的 37%、38% ,CTV的 2 7%、33% ;适形野的处方剂量 (CTV的95 %体积剂量 )同常规野和扩大野 ,但其所覆盖的肿瘤体积占GTV的 10 0 %。 ( 3)常规野、扩大野和适形野GTV的 10 0 %体积剂量分别为 4 4、5 7、6 2Gy ;肺V2 0 分别为 2 3%、31%、2 0 %。结论 食管癌常规放射治疗技术的方法不能使肿瘤靶体积的剂量分布均匀且达不?
Objective To assess the dose distribution by three dimensional conformal radiation treatment planning(3DRTP)for the primary lesion and normal surrounding tissues around esophageal carcinoma. Methods Twenty untreated esophageal carcinoma patients were immobilized and simulated by CT simulator in the treatment position. The field center was marked by barium meal while being simulated. The images were transferred through Lantis local network to the treatment planning system (CMS-Focus). The gross tumor volume (GTV), clinical target volume (CTV) and planning target volume (PTV) were outlined basing on the findings of esophagogram, esophagoscopy, and CT images. Three treatment plans were designed: 1.Conventional technique, 2. Enlarged field technique and 3. Three dimensional conformal radiation (3DCRT). Results 1. The average dimension of the tumor were 4.3 ?cm (right-left) and 2.9 ?cm (anterior-posterior) shown on CT scan. The deviation of field center along X, Y, Z axis was 3.7?mm to the left, 9.6?mm cephalad and 6.4?mm anteriorly when we compared the conventional technique with 3DCRT. 2. The volumes of GTV, CTV covered by prescription dose (D T60?Gy/30 F/6 weeks) were 37%, 38% and 27%, 33%, respectively for conventional technique and enlarge field technique. The volume of GTV and CTV covered by prescription dose was 95% and 100% in 3DCRT. 3. The dose received by GTV from conventional technique, enlarge field technique and 3DCRT were 44?Gy, 57?Gy and 62?Gy, respectively. The lung V 20 was 23%, 31% and 20%, respectively. Conclusions 3DCRT can well achieve ideal dose distribution and coverage to the target volumes and spare the normal tissues at the same time, as compared with the conventional and enlarged field radiotherapy techniques.
出处
《中华放射肿瘤学杂志》
CSCD
北大核心
2004年第4期273-277,共5页
Chinese Journal of Radiation Oncology
关键词
三维治疗计划系统
评估
食管癌
常规放射治疗
肿瘤剂量
分布
Esophageal neoplasms
Dose distribution
Three-dimensional radiotherapy planning,computer-assisted
