非小细胞肺癌三维适形放疗中再次CT定位对靶区及正常组织剂量学影响的研究  

The impact on the tumor volume and normal tissue dosimetry by scanning CT repeatly and changing treatment plan for non-small cell lung cancer

作　　者：兰卫光[1,2] 王振光[1] 刘长民[2] 宁方玲[2] 马隆波[2] 郝延璋[2] 

机构地区：[1]青岛大学医学院附属医院PET-CT中心,青岛266005 [2]滨州医学院附属医院肿瘤科

出　　处：《滨州医学院学报》2015年第4期285-287,共3页Journal of Binzhou Medical University

摘　　要：目的研究非小细胞肺癌(NSCLC)放疗过程中再次CT定位及相应放疗计划修改对肿瘤区及正常组织剂量学影响。方法对53例经病理证实的NSCLC患者放疗过程中进行再次定位,根据肿瘤及肺体积变化,修改放疗计划,通过拟合两次计划,分析叠加的剂量体积参数,与不修改的放疗计划的剂量体积参数比较。结果放疗计划修改前照射次数为(20.0±4.2)次,计划修改后GTV缩小了(71.98±34.6)cm3,且GTV变化与计划修改前照射次数呈正相关关系,r=0.497,P=0.006。最初设计的总计划与再次CT设计的计划拟合后患侧肺和全肺的平均受量分别下降了(4.6±10.1)%、(4.1±8.7)%,P值分别为0.03和0.02。拟合叠加计划与初次总的计划比较,心脏的V30受照射剂量下降了(2.68±1.3)%,脊髓的Dmax下降了(12.4±2.8)%。结论三维适形放疗中肿瘤体积发生退缩,可以适时地修改放疗计划以减少正常组织的受照射剂量,从而可以推量照射以提高肿瘤的受照射剂量。Objective To study the change of target volume during radiotherapy for nowsmall cell lung cancer （NSCLC） and the inference of treatment plan changing for normal tissue. Methods Fifty-three NSCLC patients were treated with 3D-CRT scanned by CT repeatedly and treatment plan changed according to the tumor and lung volume change. Results Totally patients with （20.0± 4.2） irradiation fractions before treatment plan changing. The GTV shrinkaged （71.98± 34.6） and the change of GTV was positively correlated with irradiation fractions before radiotherapy plan changing（r= 0. 497, P = 0. 006）. Mean lung dose of ipsilateral and all lung descended （ 4.6 ± 10.1 ） and （ 4. 1± 8.7 ）, compared with the first plan. V30 irradiated dose dropped （2.68±1.3）% and the Dmax of spinal cord descended （12.4 ±2.8） %. Conclusion Primary tumor volume changed constantly during 3D-CRT, we can duly modify radiotherapy plan to reduce the exposure dose of normal tissue, which could im- prove the irradiated dose of the tumor.

关 键 词：非小细胞肺癌 三维适形放疗 剂量体积参数 计划修改 

分 类 号：R734.2[医药卫生—肿瘤]