乳腺癌保乳术后部分乳腺三种放疗计划的剂量学比较  

Dosimetric comparison of three techniques in treatment of accelerated partial breast irradiation

作　　者：姚晖[1] 邱健健[2] 王芸[1] 徐志勇[2] 

机构地区：[1]上海市杨浦区市东医院放疗科,200438 [2]复旦大学附属肿瘤医院放疗科

出　　处：《中华放射医学与防护杂志》2014年第5期358-361,共4页Chinese Journal of Radiological Medicine and Protection

摘　　要：目的 比较容积弧形调强（VMAT）、固定野动态调强（IMRT）及三维适形放疗（3D-CRT）技术对乳腺癌保乳术后采用部分乳腺放疗的剂量学差异.方法 选取20例临床分期为T1-2N0M0的早期乳腺癌保乳术后患者进行VMAT,并同时设计IMRT及3D-CRT,比较3种计划的剂量学参数,包括剂量-体积直方图（DVH）、靶区剂量适形度、靶区及危及器官的剂量、机器跳数及治疗时间.结果 IMRT及VMAT计划靶区剂量分布优于3D-CRT计划,其中最大剂量,平均剂量及适形指数（CI）组间比较差异具有统计学意义（F=14.86、8.57、18.23,P＜0.05）.正常组织受量：VMAT计划在患侧乳腺V5上优于IMRT及3D-CRT计划（F=5.83,P＜0.05）;IMRT在患侧肺V20、V5及D5上有优势（F=16.39、3.62、4.81,P＜0.05）;在对侧肺的统计中,IMRT计划在最大剂量及D5上可以得到比VMAT和3D-CRT更低的剂量（F=3.99、3.43,P＜0.05）;VMAT、3D-CRT和IMRT计划所需机器跳数值分别为621.0±111.9、707.3±130.9、1161.4±315.6,计划间的差异有统计学意义（F=31.30,P ＜0.05）.VMAT、3D-CRT和IMRT计划所需治疗时间分别为（1.5±0.2）、（7.0±1.6）、（11.5±1.9） min.结论 IMRT和VMAT计划靶区剂量分布优于3D-CRT计划,而不提高患侧肺剂量.对于部分乳腺癌的放疗,容积弧形调强放疗在降低机器跳数和减少治疗时间方面具有明显优势.Objective To dosimetrically compare three delivery techniques of VMAT,IMRT and 3D-CRT in the treatment of accelerated partial breast irradiation （APBI）.Methods Twenty patients with T1/2N0M0breast cancer were treated with VMAT.These cases were subsequently re-planned using static gantry IMRT and 3D-CRT technology to evaluate dosimetric differences.Dosimetric parameters including dose conformity index （CI）,dose volume histogram （DVH） analysis of normal tissue coverage,dose parameters of PTV and normal tissues were evaluated,the delivery parameters including MU and delivery time were also analyzed.Results The IMRT and VMAT plans provided lower maximum dose,better mean dose and more conformal target dose distributions than the 3D-CRT plans （F =14.86,8.57,18.23,P ＜0.05）.The volume of ipsilateral breast receiving 5 Gy for VMAT technique was significantly less than that of3D-CRTor IMRT（F=5.83,P＜0.05）.The ipsilateral lung volume receiving 20 Gy （V20）,5 Gy（V5） and the 5％ volume dose （D5） of IMRT were superior to those of 3D-CRT and VMAT（F =16.39,3.62,4.81,P ＜ 0.05）.The low volume dose distributions of D5 in contralateral lung for IMRT was better than that of VMAT and 3D-CRT（F =3.99,3.43,P ＜ 0.05）.The total mean MUs for VMAT,3D-CRT and IMRT were 621.0 ± 111.9,707.3 ± 130.9 and 1161.4 ± 315.6,respectively （F =31.30,P ＜ 0.05）.The average machine delivery time was（1.5 ± 0.2）min for the VMAT plans,（7.0 ± 1.6）min for the 3D-CRT plans and （11.5 ± 1.9）min for the IMRT plans.Conclusions VMAT and IMRT techniques offer improved dose conformity as compared with 3D-CRT techniques without increasing dose to the ipsilateral lung.In terms of MU and delivery time,VMAT is more efficient for APBI than conventional 3D-CRT and static beam IMRT.

关 键 词：乳腺癌 容积弧形调强放疗 适形调强放疗 部分乳腺加速放疗 

分 类 号：R737.9[医药卫生—肿瘤] R730.55[医药卫生—临床医学]