胸部不均质组织校正对肺癌患者剂量学影响的探讨  

Study for dosimetry influence of heterogeneous structure in lung cancer radiotherapy

作　　者：周莉钧[1] 徐志勇[1] 傅小龙[1] 常熙[1] 胡伟刚[1] 李龙根[1] 

机构地区：[1]复旦大学附属肿瘤医院放疗科,复旦大学上海医学院肿瘤学系,上海200032

出　　处：《中国癌症杂志》2010年第7期539-542,共4页China Oncology

摘　　要：背景与目的:胸部肺等不均质组织的密度差异性较大,计划过程中组织密度校正与否,在体内会产生不同的剂量学影响。因此,本研究旨在探讨不均质组织校正,在肺癌不同计划方式时对剂量学的影响。方法:选取临床已经治疗的肺癌患者14例,分别应用6MV光子线进行常规不校正计划、常规不校正计划校正计算及三维适形校正计划。各计划处方量均给予60Gy,两常规计划处方给在等中心处,三维适形校正计划处方给在能包绕95%计划靶体积(planning target volume,PTV)的剂量面上,分别比较各计划PTV及危及器官受量差异。结果:PTV平均受量三维适形校正计划比常规不校正计划及常规校正计划校正计算分别增高8.4%和0.3%;95%PTV受量(D95%)分别增高21.1%和15.4%;适形指数(comformity index,CI)分别增高24%和20%;全肺接受≥20Gy照射的体积百分比(V20)分别增高38.9%和35.3%,全肺平均剂量分别增高47.3%和42%;心脏平均剂量分别增高67.3%和64.3%;食管平均剂量分别增高68.5%和64.9%;脊髓最大剂量分别增高45.3%和42.8%。结论:肺癌三维适形校正计划方式相对于常规不校正计划与常规校正计划校正计算在靶区剂量方面有明显的改善和保证,但要注意周围危及器官的受量一定程度增加的临床意义。Background and purpose：Thorax radiotherapy is mainly using on lung cancer and esophagus cancer.The density difference of the thorax,lung and similar heterogeneous structures are comparable.Whether the density of these structures have been corrected or not produces different dosimetry in？ uences in the body.This paper studied the influence of heterogeneous structure correction on dosimetry in the different plan of lung cancer.Methods：Fourteen patients with lung cancer underwent radiation treatment planning.Three kinds of treatment plans were calculated for each patient.These plans are：the traditional uncorrected plan,traditional corrected plan and the 3D conformal corrected plan.The prescription for each plan was administered as 60 Gy,the prescriptions of the two traditional plans were given at the isocenter,the prescription for the 3D conformal corrected plan was given at the dose surface,which can cover 95% PTV.The target dose and the critical organ dose were compared.Results：Compared with the traditional uncorrected plan and the traditional corrected plan,the mean dose of PTV of the 3D conformal corrected plan was increased by 8.4% and 0.3% while 95% of PTV dose was increased by 21.1% and15.4%.The ratio of the volume of the entire lung received at least 20 Gy which resulted in an increase of 35.3% and 38.9%.The mean dose of esophage was increased by 64.9% and 68.5%.The max dosage to the spinal cord was increased by 42.8% and 45.3%,separately.Conclusion：Compared with the traditional uncorrected plan and traditional corrected plan,the 3D conformal corrected plan of lung cancer can very obviously guarantee the target dosage.However,it also increases the dosage to the critical organ.

关 键 词：不均质校正 肺癌 三维适形 

分 类 号：R734.2[医药卫生—肿瘤]