摘要
[目的]比较三维适形放疗(three dimensional-conformal radiotherapy,3D-CRT)、调强适形放疗(intensity-modulated radiotherapy,IMRT)和容积调强放疗(volumetric modulated arc therapy,VMAT)3种技术在乳腺癌术后放疗中的心脏剂量学差异,重点评估其对左前降支冠状动脉(left anterior descending coronary artery,LAD)的剂量学影响,为临床优选放疗方案提供依据。[方法]研究共纳入20例左侧乳腺癌保乳术后患者。基于每例患者的CT定位图像,分别制定3D-CRT(切线野技术)、IMRT(7野均分方案)和VMAT(双弧旋转照射)3种放疗计划。评估心脏平均剂量(Dmean)、心脏V20和LAD V40等关键剂量参数,并分析其与计划靶区(planning target volume,PTV)与心脏距离、心脏体积等解剖因素的相关性。[结果]VMAT在心脏保护方面显著优于其他两组(P<0.001):其中VMAT心脏Dmean中位数为3.49 Gy,低于IMRT(3.50 Gy)和3D-CRT(4.56 Gy);心脏V20中位数为1.13%,较IMRT(1.62%)和3D-CRT(4.05%)更低;且LAD V40中位数为0,显著低于3D-CRT的39.49%和IMRT的5.34%(P<0.001)。VMAT组所有病例的LAD V40均满足临床指南要求(达标率100.0%),而3D-CRT和IMRT组达标率仅分别为5.0%和75.0%。相关性分析显示,各计划PTV心脏距离与LAD V40均呈负相关(P<0.05),当距离<6 mm时,3D-CRT的LAD V40超标率达85.0%以上。[结论]VMAT技术可显著降低心脏及LAD的受照剂量,尤其PTV与心脏距离较近时优势更为明显。PTV与心脏距离是影响LAD受照剂量的重要解剖因素,可作为个体化放疗技术选择的参考依据。
[Objective]To compare the cardiac dosimetric differences among three dimensional-conformal radiotherapy(3D-CRT),intensity-modulated radiotherapy(IMRT)and volumetric modulated arc therapy(VMAT)for post-operative radiotherapy of left-sided breast cancer,with a focus on the dosimetric impact on the left anterior descending coronary artery(LAD).[Methods]This study enrolled 20 patients who underwent breast-conserving surgery for left-sided breast cancer.For each patient,three distinct radiotherapy plans were designed based on CT simulation images:3D-CRT(using a tangential field technique),IMRT(a 7-field equispaced plan)and VMAT(dual-arc rotation irradiation).Key dosimetric parameters,including the mean heart dose(Dmean),heart V20(volume receiving≥20 Gy),and LAD V40(volume of LAD receiving≥40 Gy),were evaluated.Correlations between these dose parameters and anatomical factors,such as the heart-planning target volume(PTV)distance and heart volume,were analyzed.[Results]VMAT demonstrated significantly superior cardiac protection compared to the other two techniques(P<0.001).The median mean heart dose was 3.49 Gy for VMAT,lower than that for IMRT(3.50 Gy)and 3D-CRT(4.56 Gy).The median heart V20 was 1.13%for V¯AT,also lower than that for IMRT(1.2%)and 3D-CRT(4.05%).Notably,the median LAD V40 was 0 for VMAT,significantly lower than the 39.49%for 3D-CRT and 5.34%for IMRT(P<0.001).All cases(100.0%)in the VMAT group met the clinical guideline constraint for LAD V40,whereas the compliance rates were only 5.0%and 75.0%in the 3D-CRT and IMRT groups,respectively.Correlation analysis revealed a significant negative correlation between the heart-PTV distance and LAD V40 across all plans(P<0.05).When this distance was less than 6 mm,the rate of LAD V40 exceeding the guideline constraint was over 85.0%in the 3D-CRT group.[Conclusion]VMAT significantly reduces radiation dose to the heart and the LAD.Its advantage is particularly pronounced when the planning target volume is in close proximity to the heart.The heart-PTV distance is an important anatomical factor influencing LAD dose and may serve as a valuable reference for the individualized selection of radiotherapy techniques.
作者
郑博雅
任毅
朱志坚
王加阳
张青
李硕
韩济华
骆红蕾
宋亚颀
ZHENG Boya;REN Yi;ZHU Zhijian;WANG Jiayang;ZHANG Qing;LI Shuo;HAN Jihua;LUO Honglei;SONG Yaqi(The Affiliated Huai'an No.1 People's Hospital of Nanjing Medical University,Huai'an 223300,China)
出处
《肿瘤学杂志》
2026年第2期134-140,共7页
Journal of Chinese Oncology
关键词
乳腺肿瘤
心脏保护
适形放疗
调强适形放疗
容积调强放疗
左前降支冠状动脉
剂量学分析
解剖因素
个体化治疗
breast neoplasms
cardioprotection
conformal radiotherapy
intensity-modulated radiotherapy
volumetric modulated arc therapy
left anterior descending coronary artery
dosimetric analysis
anatomical factors
individualized treatment
