食管癌扩大照射野放射治疗的剂量学研究  

Assessment of Dose Distribution of the Esophageal Cancer in the Treatment Using the Extended Field Radiotherapy

作　　者：易金玲[1] 张萍[1] 谢聪颖[1] 邓霞[1] 赵亮[1] 吴式琇[1] 

机构地区：[1]温州医学院附属第一医院放疗科,浙江温州325000

出　　处：《中国医学物理学杂志》2009年第5期1395-1398,共4页Chinese Journal of Medical Physics

摘　　要：目的:应用三维适形放射治疗计划对10例胸段食管癌的扩大野和常规四野以及常规三野照射进行对比分析,并探讨食管癌扩大野照射技术的剂量分布特点。材料和方法:进行根治性同步放化疗的胸段食管癌患者10例,CT扫描后由医生勾画靶区,淋巴结引流区和危及器官,给每例患者设计3种放疗计划即扩大野照射、常规四野照射和常规三野照射,再对各个计划DVH的各项参数进行综合评价分析。结果:三种照射方式的剂量分布均能满足肿瘤靶区剂量要求,靶区内剂量分布相对均匀,各组间无显著差异,而靶区内剂量以扩大野照射最高;扩大野的淋巴引流区的受照剂量较其它两计划高;对于危及器官,扩大野的双肺V20高于其它两计划,扩大野60%心脏的受照剂量高于常规四野和常规三野,常规四野高于常规三野,脊髓的受照剂量最大值和平均值以常规三野最小。结论:食管癌扩大野照射靶区内照射剂量高于其他两种照射,扩大野靶区包括了淋巴引流区,降低了区域局部复发的概率,临床结果提示有利于提高生存率。Objectlve： Comparative analysis of 3-dimensional conformal radiation therapy （3-DCRT） plans with extended-fields, conventional 3-fields and conventional 4-fields using Varian Cadplan treatment planning system, as well as studying the dose distribution of the extended-fields in 10 thoracic esophageal cancer cases. Methods： 10 thoracic esophageal carcinoma patients who had received concurrent chemoradiotherapy were enrolled into this study. The localized CT data were transfered to the treatment planning system （TPS） （Varain CadPlan） and 3-dimensional reconstruction. All the gross tumor volume（GTV）, clinical target volume （CTV）, planning target volume （PTV）,organs at risk （OARS） and lymphatic drainage volume were delineated by the oncologist, and three treatment plans including extended fields, conventional 4-fields and conventional 3-fields were designed for each patient respectively. The related physical parameters for each treatment planning were evaluated by the DVH （Dose Volume Histogram）. Final analysis of groups comparison in paired T-test sample were obtained by using SPSS8.0 package. Results： In all the three types of the designations for all the patients, the 90% and 95% isodose covered almost 100% of the GTV volume, and the dose uniformity of the target volume was good. It showed no significant differences between any groups. In the extended fields plan, both the target volume and lymphatic drainage volume gained higher dose than the other two. Its maximum, average and median dose achieved to 45 Gy which is required for the 90% control probability of sub-clinical lesions, but its minimum dose is 29.29 Gy which is lower than the prophylactic dose. To the OARs, the lung V20 of extended fields plan was 31.90 Gy, which was higher than that of conventional 3F and 4F plan. The dose of 60 percent of heart volume in extended fields plan was 42.03 Gy, which was also higher than 3F （25.80 Gy） and 4F （35.70 Gy）. The maximum and the average dose of spinal cord in conventi

关 键 词：食管癌 扩大野放射治疗 剂量体积直方图 

分 类 号：R73[医药卫生—肿瘤]