弥散加权成像瘤内及瘤周影像组学预测乳腺癌组织学分级

Intratumoral and peritumoral radiomics based on diffusion weighted imaging for predicting histological grade of breast cancer

目的观察弥散加权成像(DWI)瘤内及瘤周影像组学预测乳腺癌组织学分级的价值。方法回顾性分析700例经病理诊断单发乳腺癌患者术前DWI,按8∶2比例分为训练集(n=560,含381例Ⅰ+Ⅱ级和179例Ⅲ级)和测试集(n=140,含95例Ⅰ+Ⅱ级和45例Ⅲ级)。手动勾画瘤内ROI(ROI瘤内),将其自动外扩3、5 mm,获得瘤周ROI(ROI+3 mm和ROI+5 mm),以及瘤内-瘤周ROI(ROI瘤内+3 mm、ROI瘤内+5 mm)。提取并筛选最佳影像组学特征,构建影像组学模型(RM)用于预测乳腺癌组织学分级;绘制受试者工作特征曲线,计算曲线下面积(AUC),评估各模型预测效能。以校准曲线评估模型校准度,以决策曲线分析(DCA)评估其临床实用性。结果RM瘤内、RM+3 mm、RM+5 mm、RM瘤内+3 mm及RM瘤内+5 mm在训练集的AUC分别为0.750、0.724、0.749、0.833及0.807,在测试集分别为0.723、0.718、0.736、0.759及0.782。各模型AUC差异在训练集中均有(P均<0.01)而在测试集均无统计学意义(P均>0.05),且校准度均较高。DCA显示阈值为0.02~0.88时RM瘤内+瘤周在训练集、阈值为0.40~0.72时其在测试集的临床净收益更大。结论DWI瘤内及瘤周影像组学均可有效预测乳腺癌组织学分级,瘤内-瘤周影像组学诊断效能更高。

Objective To observe the value of intratumoral and peritumoral radiomics based on diffusion weighted imaging(DWI)for predicting histological grade of breast cancer.Methods Preoperative DWI data of 700 patients with single breast cancer diagnosed by pathology were retrospectively analyzed.The patients were divided into training set(n=560,including 381 of gradeⅠ+Ⅱand 179 of gradeⅢ)and test set(n=140,including 95 of gradeⅠ+Ⅱand 45 of gradeⅢ)at the ratio of 8∶2.Intratumoral ROI(RO_(Iintra))was manually delineated on DWI,which was automatically expanded by 3 mm and 5 mm to decline peritumoral ROI(ROIper,i including ROI3 mm and ROI5 mm),then intratumoralperitumoral ROI(RO_(Iintra+3 mm),RO_(Iintra+5 mm))were obtained.The optimal radiomics features were extracted and screened,and the radiomics model(RM)for predicting the histological grade of breast cancer were constructed.Receiver operating characteristic curves were drawn,and the areas under the curve(AUC)were calculated to evaluate the predictive efficacy of each model.Calibration curve method was used to evaluate the calibration degree,while decision curve analysis(DCA)was performed to explore the clinical practicability of each model.Results AUC of RM_(intra),RM_(+3 mm),RM+5mm,RM_(intra+3 mm)and RM_(intra+5 mm)was 0.750,0.724,0.749,0.833 and 0.807 in training set,while was 0.723,0.718,0.736,0.759 and 0.782 in test set,respectively.In training set,significant differences of AUC was found(all P<0.01),while in test set,no significant difference of AUC was found among models(all P>0.05).The calibrations of models were all high.DCA showed that taken 0.02—0.88 as the threshold,the clinical net benefit of RM_(intra+per)were greater in training set,while taken 0.40—0.72 as the threshold,the clinical net benefit of RM_(intra+per)was greater in test set.Conclusion Both DWI intratumoral and peritumoral radiomics could effectively predict histological grade of breast cancer.Combination of intratumoral and peritumoral radiomics was more effective.