早期乳腺癌保乳术后简化逆向调强放疗的剂量学研究  

Dosage studies on simplified inverse intensity modulated radiotherapy in patients with early-stage breast cancer after breast-conserving surgery

作　　者：郝福荣[1] 吕春燕[2] 王金鹏[1] 王培合[1] 李勇[1] 马瑞忠[1] 王明臣[1] 

机构地区：[1]山东省潍坊市人民医院放疗科,261041 [2] 滕州市工人医院肿瘤科

出　　处：《国际肿瘤学杂志》2014年第9期692-696,共5页Journal of International Oncology

基　　金：基金项目：山东省自然科学基金（ZR2009CM081）

摘　　要：目的：比较早期乳腺癌保乳术后三维适形放疗（3DCRT）及简化逆向动态调强放疗（IMRT）剂量学特点。方法随机选择14例早期乳腺癌保乳术后患者（4例左侧乳腺癌），每例患者选用6 MV-X线分别设计3DCRT、IMRT计划，全乳腺50 Gy/25次。3DCRT组：采用切线野照射，瘤床区不加量；IMRT组：采用逆向动态调强技术，以2对类切线野为调强主野的入射方向，瘤床区同步加量10 Gy/25次。根据剂量体积直方图（DVH）进行适形度指数（CI）及不均匀度指数（HI）、危及器官受照射剂量及体积的评价。结果与3 DCRT计划比较，IMRT计划降低了患侧肺、左侧乳腺癌患者心脏的高剂量受照体积，提高了其低剂量受照体积，DVH叉点剂量分别为（25．16±9．11）Gy、（28．63±10．41）Gy；IMRT组和3DCRT组计划健侧乳腺的V10差异无统计学意义[（4．13±5．17）％∶（1．99±2．43）％，t＝2．11，P＞0．05]，IMRT计划D30、平均剂量均较3DCRT增高[（2．23±1．77）Gy ∶（1．20±0．46）Gy，t＝2．58，P＜0．05；（2．35±1．59）Gy ∶（1．54±0．88）Gy，t＝3．15，P＜0．01）]；2组计划的HI差异无统计学意义[（1．25±0．10）∶（1．23±0．11），t＝1．25，P＞0．05]，IMRT计划CI 高于3DCRT[（0．75±0．07）∶（0．62±0．09），t＝5．68，P＜0．0001]。结论早期乳腺癌保乳术后四野简化逆向动态 IMRT技术较3 DCRT技术的主要优势在于瘤床同步加量，同时可以降低患侧肺的高剂量受照射体积，明显改善计划靶区CI，但HI无显著改善。早期乳腺癌保乳术后四野简化逆向动态IMRT技术是一种简便、合理、可行的计划设计方法。Objective To compare the dosage characteristics between three-dimensional conformal radiotherapy （3DCRT）plan and simplified inverse dynamic intensity modulated radiotherapy （IMRT）in patients with early-stage breast cancer after breast-conserving surgery.Methods 3DCRT and IMRT treament plans were designed for 14 female patients with early-stage breast cancer after breast-conserving surgery,4 of whom were left breast cancer cases.A dose of 50 Gy in 25 fractions to the whole ipsilateral breast was delivered using 6 MV photons for 3DCRT or IMRT.For 3DCRT plans,tangential field irradiation was adopted.While for IMRT,reverse dynamic intensity modulated technology was done through two pairs of tangential-likely fields, and 10 Gy was boosted to the tumor bed concomitantly in 25 fractions.The conformity index （CI）,heterogenei-ty index （HI）,dose and volume of organs at risk were evaluated by dose volume histograms （DVH）.Results Compared with 3DCRT plans for ipsilateral lung,the high dose volumes were reduced and the low dose volumes were increased in IMRT plans.The same phenomenon was also observed for the heart of the patient with left breast cancer.The crosspoint doses of 3DCRT DVH and IMRT DVH for lung or heart were （25.16 ±9.11） Gy,（28.63 ±10.41 ）Gy respectively.There was no difference between the two plans in the V10 of contra-lateral breast [IMRT（4.13 ±5.17）%∶3DCRT（1.99 ±2.43）%,t=2.11,P＆gt;0.05],but the D30 and mean of IMRT plan were higher than that of 3DCRT [（2.23 ±1.77）Gy ∶（1.20 ±0.46）Gy,t=2.58,P＆lt;0.05;（2.35 ±1.59）Gy ∶（1.54 ±0.88）Gy,t=3.15,P＆lt;0.01].The difference in HI between the two plans was not observed [IMRT（1.25 ±0.10）∶3DCRT（1.23 ±0.11）,t=1.25,P＆gt;0.05].While the CI of IMRT plans were improved compared with 3DCRT [（0.75 ±0.07）∶（0.62 ±0.09）,t =5.68,P＆lt;0.000 1]. Conclusion Compared with 3DCRT plan in patients with early-stage breast cancer after breast-conserving surgery,the main advantages of four fields

关 键 词：乳腺肿瘤 调强放射治疗 放射治疗剂量 保留乳房术 

分 类 号：R737.9[医药卫生—肿瘤]