VMAT旋转调强多中心照射技术在全脑全中枢放疗中的应用  

Application of Volumetric Modulated Arc Therapy with Multi Centers Planning Method in Craniospinal Irradiation

作　　者：张怀文[1] 钟晓鸣[1] 胡海芹[1] 洪潮[1] ZHANG Huaiwen;ZHONG Xiaoming;HU Haiqin(Jiangxi Cancer Hospital,Nanchang,330029)

机构地区：[1]江西省肿瘤医院,330029

出　　处：《实用癌症杂志》2021年第9期1536-1540,1544,共6页The Practical Journal of Cancer

基　　金：江西省卫生厅科技计划项目(编号:20203570)。

摘　　要：目的比较全脑全中枢常用放疗技术的靶区及其周围正常组织受照剂量的差异,为全脑全中枢患者放疗方法的临床选择提供科学依据。方法随机选取10例全脑全中枢放疗患者,经增强CT扫描后传输图像在Ecalipse13.5放疗计划系统中进行靶区勾画。每例患者分别设计三维适形计划Ⅰ,3D-CRT+IMRT调强计划Ⅱ,VMAT多中心治疗计划Ⅲ三种放疗计划。在满足PTV临床靶区达到95%处方剂量的前提下,利用3维放疗计划系统自带的剂量体积直方图(DVH)评价三种放射治疗技术的靶区和周围危及器官照射剂量和靶区剂量不均匀性指数(HI)及适形指数(CI)。结果①VMAT计划靶区的均匀性指数和适形度指数要显著优于常规CRT计划和CRT+IMRT计划。②VMAT计划晶体受量略高于3DCRT和CRT+IMRT。③3DCRT计划小肠所受照射的最大剂量显著高于计划Ⅱ和Ⅲ。④VMAT计划甲状腺平均剂量显著低于计划Ⅰ和计划Ⅱ。⑤VMAT计划的肾脏所受照射的平均剂量略高于计划I和Ⅱ。⑥计划Ⅱ的肺受照平均剂量较计划Ⅰ和计划Ⅲ略高;肺接受的低剂量照射体积V 10计划Ⅱ和Ⅲ则明显小于计划Ⅰ。⑦计划Ⅲ的心脏受照最大剂量、平均剂量及心脏高剂量区域V 20显著低于计划I和计划Ⅱ。结论VMAT多中心全脑全脊髓放疗技术既可以解决照射野衔接处剂量冷热不均问题,明显提高整个靶区范围内剂量分布的均匀性和适形度,同时又可以大幅降低患者危及器官所受的照射剂量,从而更好的保护周围正常组织。Objective To compare the radiation dosimetric difference between the target and the surrounding normal tissue in craniospinal irradiation for the common radiotherapy techniques.Methods 10 patients who have received craniospinal irradiation were chosen randomly.CT images were inputted into the Ecalipse13.5 treatment planning system.The three-dimensional conformal radiotherapy(3DCRT,plan I),three-dimensional conformal radiotherapy and intensity(3DCRT+IMRT,plan II)and volumetric modulated arc therapy(VMAT)plans were designed for each patient.The irradiation dose at the target and surrounding normal tissues,as well as the conformity index and heterogeneity index of the target region under three plans,were evaluated by the dose volume histogram.Results①The heterogeneity index(HI)and conformity index(CI)of VMAT plan were significantly better than those of 3DCRT plan and 3DCRT+IMRT plan.②The crystals received dose of VMAT was slightly higher than that of 3DCRT and 3DCRT+IMRT.③The maximum for small intestine in plan I is larger than the other 2 plans.④The average dose in thyroid of VMAT plan is smaller than those of 3DCRT and 3DCRT+IMRT plans.⑤VMAT Plan shows larger mean dose in kindey.⑥The IMRT plans exhibits higer mean irradiation doses to the lung.The IMRT plan and VMAT plan show much smaller in low-level volume(V10).⑦The maximum dose,average dose and V20 of VMAT plan were significantly lower than those of 3DCRT and 3DCRT+IMRT plans.Conclusion VMAT with muil-iso centers planning method can solve the problem of uneven dose at the junction of radiation fields.At the same time,it can greatly reduce the radiation dose of surrounding normal tissues.

关 键 词：全脑全中枢 调强放射治疗 VMAT 剂量学 

分 类 号：R739.41[医药卫生—肿瘤]