基于nnU-Net的乳腺癌放疗心脏保护策略:区域优化与自动分割  

Heart-sparing strategy for breast cancer radiotherapy based on nnU-Net:regional optimization and automatic segmentation

作　　者：黄靖涵 麦迪娜·巴吐尔 周创辉 张智[3] 邓丽媚 徐圆[1] 钟俊远[4] 周凌宏[1] 李霞[5] 秦耿耿 Huang Jinghan;Batuer Maidina;Zhou Chuanghui;Zhang Zhi;Deng Limei;Xu Yuan;Zhong Junyuan;Zhou Linghong;Li Xia;Qin Genggeng(School of Biomedical Engineering,Southern Medical University,Guangzhou 510000,China;School of Medical and Information Engineering,Gannan Medical University,Ganzhou 341000,China;Department of Radiology,Nanfang Hospital,Southern Medical University,Guangzhou 510000,China;Department of Radiology,Ganzhou Hospital of Nanfang Hospital(Ganzhou People's Hospital),Ganzhou 341000,China;Department of Radiation Oncology,Nanfang Hospital,Southern Medical University,Guangzhou 510000,China)

机构地区：[1]南方医科大学生物医学工程学院,广州510000 [2]赣南医科大学医学信息工程学院,赣州341000 [3]南方医科大学南方医院影像诊断科,广州510000 [4]南方医院赣州医院(赣州市人民医院)影像诊断科,赣州341000 [5]南方医科大学南方医院放疗科,广州510000

出　　处：《中华放射肿瘤学杂志》2025年第4期355-362,共8页Chinese Journal of Radiation Oncology

基　　金：赣州市科技项目(2022--ZD1373,2022--RC1349);广州市科技计划项目(202103000037);广东省自然科学基金(2024A1515011520)。

摘　　要：目的探究乳腺癌放疗中用心脏保护区域(RHS)替代左前降支冠状动脉(LADCA)降低心脏受照剂量的可行性和最佳外扩宽度。方法回顾性分析2022年3月至2024年1月在南方医科大学南方医院(50例为训练集,15例为内部测试集)及南方医院赣州医院(23例为外部测试集)两个中心放疗的88例左侧乳腺癌患者的数据。所有患者均为伴腋窝淋巴结转移的左侧浸润性导管癌,并已接受改良根治术及化疗。基于模拟定位CT图像,由2名放疗科医生勾画出LADCA及8个RHS。RHS勾画基于LADCA轮廓每次扩大0.5 cm,共8次。RHS宽度定义为基于LADCA轮廓外扩的宽度,分别为0.5、1.0、1.5、2.0、2.5、3.0、3.5、4.0 cm。用nnU-Net进行模型训练,用于LADCA及RHS的三维自动分割。用戴斯相似性系数(DSC)、相对体积误差(RVE)、灵敏度、特异度、95%豪斯多夫距离(HD95)对模型性能进行评价。同时,计算LADCA及各RHS的最小、最大、平均相对剂量变化(RDV)及V 5%、V 20%指标。利用最小二乘法进行相关性分析,用斜率、判定系数R^(2)评估模型拟合的准确性、LADCA和RHS的相关关系及程度,从而判断RHS对LADCA的替代效果。结果LADCA的DSC为0.415,RHS宽度为0.5、4.0 cm的DSC分别为0.718、0.835。整体上,RHS宽度越大,自动分割性能越优。外部测试集的DSC、RVE、灵敏度、特异度、HD95与内部测试集基本一致,显示模型在不同数据集上的良好鲁棒性。RDV_(min)皆为负数,RDV_(max)、RDV_(mean)均与RHS宽度成正相关。RDV_(mean)随着RHS宽度的增加而增加,从39.01%上升到75.89%。相关性分析中,RHS宽度为1.5 cm和2.0 cm时的斜率分别为0.95和1.05,两者的R^(2)和变异系数分别为0.79和0.73、21.11%和24.03%。结论基于nnU-Net训练的自动分割模型能够精准分割RHS,结合几何学指标和剂量学指标,1.5 cm宽的RHS是最适合的LADCA替代区域,该区域可以在不影响靶区剂量覆盖的同时,限制LADCA的受照剂量。ObjectiveTo investigate the feasibility and optimal expansion width of replacing the left anterior descending coronary artery(LADCA)with the region of heart sparing(RHS)to reduce cardiac radiation dose during breast cancer radiotherapy.MethodsRetrospective analysis was conducted on data from 88 patients with left-sided breast cancer who underwent radiotherapy at 2 centers:Nanfang Hospital of Southern Medical University(50 cases for the training set,15 cases for the internal test set)and Ganzhou Hospital of Nanfang Hospital(23 cases for the external test set)from March 2022 to January 2024.All patients had left-sided invasive ductal carcinoma with axillary lymph node metastasis,and had undergone modified radical mastectomy and chemotherapy.Based on simulation CT images,2 radiation oncologists delineated the LADCA and 8 RHSs.The RHSs were delineated by expanding the LADCA contour by 0.5 cm increments,totaling 8 expansions.The RHS widths were defined as 0.5,1.0,1.5,2.0,2.5,3.0,3.5,and 4.0 cm.The nnU-Net model was trained for 3D automatic segmentation of the LADCA and RHSs.Model performance was evaluated using the Dice similarity coefficient(DSC),relative volume error(RVE),sensitivity,specificity,and 95%Hausdorff distance(HD95).Additionally,the minimum,maximum,and average relative dose variations(RDV)as well as V5%and V20%indicators were calculated for the LADCA and each RHS.Correlation analysis was performed using the least squares regression,with the slope and coefficient of determination(R²)employed to evaluate the accuracy of the model fitting,the relationship between the LADCA and RHS,and the degree of their correlation,thereby assessing the substitutive effect of the RHS for the LADCA.ResultsThe DSC for the LADCA was 0.415,while the DSCs for RHS widths of 0.5 cm and 4.0 cm were 0.718 and 0.835,respectively.Overall,the automatic segmentation performance improved with increasing RHS width.The DSC,RVE,sensitivity,specificity,and HD95 for the external test set were largely consistent with those of the internal tes

关 键 词：乳腺肿瘤 放射疗法 心脏毒性 左前降支冠状动脉 分割 nnU-Net 

分 类 号：R737.9[医药卫生—肿瘤]