基于铅门固定垂直小野技术在左侧乳腺癌保乳术后放疗中的应用  

Application of vertical small field technique based on lead gate fixation in postoperative radiotherapy for left breast cancer after breast conserving surgery

作　　者：朱锦锋[1] 陈强 ZHU Jinfeng;CHEN Qiang(Department of Medical Oncology,Fujian Provincial Hospital,Fuzhou 350028,Fujian,China)

机构地区：[1]福建省立医院肿瘤内科,福建福州350028

出　　处：《右江医学》2025年第3期251-256,共6页Chinese Youjiang Medical Journal

摘　　要：目的探讨铅门固定垂直小野技术在左侧乳腺癌保乳术后调强放疗中的剂量优势和劣势。方法2021年10月至2023年8月,随机选取20例左侧乳腺癌保乳术后患者为研究对象,利用Pinnacle计划系统设计两种治疗计划方案,分别为A计划(Plan-A)和B计划(Plan-B)。Plan-A为铅门固定垂直小野调强计划,Plan-B为单纯切线野调强计划。全乳靶区PCTV处方剂量为50 Gy(2.0 Gy/次,25次),高危病灶PGTV处方剂量为60 Gy(2.4 Gy/次,25次)。在相同约束条件下进行优化,通过对比两种计划在等剂量曲线和DVH图(剂量体积直方图)上的表现,评估靶区适形性指数(CI)、均匀性指数(HI)、D95(95%靶区体积所受剂量)、剂量热点区域V55体积(接受55 Gy剂量靶区照射体积,其他类推)、V66体积和危及器官受量。结果两种计划均能满足处方剂量要求,Plan-A在靶区上能获得较完美的适形剂量曲线,其D95优于Plan-B,靶区PCTV、PGTV的CI值更接近于1,差异均有统计学意义(P<0.05)。Plan-A靶区PCTV剂量热点区域V55体积显著小于Plan-B,其HI值明显降低更接近于0,差异有统计学意义(P<0.05);而对于靶区PGTV剂量热点区域V66体积,两组之间差异无统计学意义(P>0.05)。危及器官受量方面,Plan-A与Plan-B在心脏剂量上比较,前者可显著降低心脏V5、V10、V20、V30、Dmean的剂量受量,差异有统计学意义(P<0.05)。Plan-A方案中胸壁皮肤受量如V40、V45及Dmean和健侧乳腺的V5、Dmean相比较于Plan-B均有所降低,差异有统计学意义(P<0.05)。而两种计划左肺和右肺的受照射剂量差异无统计学意义(P>0.05)。从机器跳数(MU)来看,Plan-A的MU为(776±156),Plan-B的MU为(701±139),Plan-A增加了大约10.7%的MU,差异有统计学意义(P<0.05)。结论对于左侧乳腺癌保乳术后放疗,基于铅门固定垂直小野调强计划有较好的靶区覆盖率,靶区的适形度、剂量均匀性更突出,更好地保护了心脏、皮肤和健侧乳腺,具有较高的临床应Objective To investigate the advantages and disadvantages of vertical small field technique based on lead gate fixation in intensity modulated radiotherapy after left breast cancer conserving surgery.Methods From October 2021 to August 2023,20 patients with left breast cancer after left breast conserving surgery were randomly selected as study objects,and Pinnacle planning system was used to design two groups of treatment plans,namely Plan-A and Plan-B.Plan-A was an intensity modulated radiotherapy plan with vertical small field technique based on lead gate fixation,and Plan-B was the simple tangential field intensity modulated radiotherapy plan.The prescribed dose of PCTV in the whole breast target area was 50 Gy(2.0 Gy/time,25 times),and the prescribed dose of PGTV for high-risk lesions was 60 Gy(2.4 Gy/time,25 times).Optimization was carried out under the same constraint conditions.By comparing the performance of the two groups of plans on the isodose curve and DVH diagram(dose volume histogram),the target conformity index(CI),homogeneity index(HI),D95(the dose received by 95%of the target volume),the volume of the dose hot spot V55(the dose received by 55 Gy,and so on for other doses),the V66 volume and dose of organs at risk were evaluated.Results Both groups of plans could meet the prescribed dose requirements,Plan-A could obtain a perfectly conformal dose curve in the target area,its D95 was better than that of Plan-B,and the CI values of PCTV and PGTV in the target area were closer to 1,and differences were all statistically significant(P<0.05).The volume of V55 in the PCTV dose hotspot area of Plan-A was significantly smaller than that of Plan-B,and its HI value was significantly reduced and closer to 0,and differences were all statistically significant(P<0.05).However,for the volume of V66 in the hot spot area of PGTV dose in Plan-A,there was no statistically significant difference between the two groups(P>0.05).In terms of the dose of organs at risk,compared with Plan-B in the cardiac dose,Plan-A could

关 键 词：左侧乳腺癌 放疗剂量 调强放疗 铅门固定 

分 类 号：R737.9[医药卫生—肿瘤]