联合含瘤周肿瘤全体积CT影像组学特征及临床相关独立预测因子列线图预测肺腺癌淋巴血管侵犯

目的 观察基于含瘤周的肿瘤全体积(GPTV) CT影像组学特征及临床相关独立预测因子构建的联合模型列线图预测肺腺癌淋巴血管侵犯(LVI)的价值。方法 回顾性分析142例经病理证实的肺腺癌患者,以7 ∶ 3比例将其随机分为训练集(n=100,40例LVI阳性、60例LVI阴性)和验证集(n=42,17例LVI阳性、25例LVI阴性)。以单因素分析及多因素logistic回归分析筛选肺腺癌LVI的临床相关独立预测因子,以之构建临床模型。分别基于肿瘤全体积(GTV)及含瘤周3 mm、6 mm、9 mm的GPTV (GPTV₃、GPTV₆和GPTV₉)的增强动脉期CT图提取并筛选最佳影像组学特征,构建影像组学模型,即GTV、GPTV₃、GPTV₆和GPTV₉模型并筛选最佳者;基于后者的影像组学评分和临床相关独立预测因子构建联合模型,绘制列线图进行可视化。以受试者工作特征(ROC)曲线评估各模型预测肺腺癌LVI的效能,以决策曲线分析(DCA)评价联合模型列线图的价值。结果 性别、吸烟和毛刺征均为肺腺癌LVI的临床相关独立预测因子(P均＜0.05)。分别基于GTV、GPTV₃、GPTV₆及GPTV₉筛选出7、16、10及8个最佳影像组学特征,用于构建GTV、GPTV₃、GPTV₆及GPTV₉模型。GPTV₃模型预测训练集、验证集肺腺癌LVI的曲线下面积(AUC)分别为0.82、0.77,均高于GTV (0.79、0.72,Z=3.74、2.62,P均＜0.01)、GPTV₆(0.80、0.72,Z=2.40、2.06,P均＜0.05)及GPTV₉(0.77,0.72,Z=3.03、2.59,P均＜0.01),为最佳影像组学模型。联合模型列线图(0.86、0.73,Z=2.66、2.31,P均＜0.05)及GPTV₃模型(0.82、0.77,Z=2.23、2.54,P均＜0.05)于训练集和验证集的AUC均高于临床模型(0.73、0.61),而联合模型列线图与GPTV₃模型的AUC差异均无统计学意义(Z=1.57、0.88,P均＞0.05)。阈值取0.20~0.50时,联合模型列线图与GPTV₃模型的净获益相当,且均大于临床模型。结论 基于GPTV₃影像组学特征及临床相关独立预测因子的列线图可有效预测肺腺癌LVI。

Nomogram based on CT radiomics features of gross peritumoral tumor volume and clinical relevant independent predictors for predicting lymphovascular invasion of lung adenocarcinoma

Objective To explore the value of the nomogram based on CT radiomics features gross peritumoral tumor volume (GPTV) and clinical relevant independent predictors for predicting lymphovascular invasion (LVI) of lung adenocarcinoma. Methods Data of 142 patients with pathologically confirmed lung adenocarcinoma were retrospectively analyzed. The patients were randomly divided into training set (n=100, including 40 LVI-positive and 60 LVI-negative ones) and validation set (n=42, including 17 LVI-positive and 25 LVI-negative) at the ratio of 7:3. Univariate analysis and multivariate logistic regression analysis were used to select clinical relevant independent predictors for LVI of lung adenocarcinoma to construct the clinical model. Based on enhanced CT arterial phase images of gross tumor volume (GTV) and GPTV incorporating peritumoral 3 mm, 6 mm and 9 mm regions (GPTV₃, GPTV₆ and GPTV₉), the best radiomics features were extracted and screened to construct radiomics models, including GTV, GPTV₃, GPTV₆ and GPTV₉ models. Then the best radiomics model was selected. A combined model was constructed based on radiomics score of the best radiomics model and clinical relevant independent predictors, and a nomogram was drawn for visualization of the combined model. Receiver operating characteristic (ROC) curves were drawn to evaluate the efficacy of each model for predicting LVI of lung adenocarcinoma, and decision curve analysis (DCA) was used to assess the value of the combined model nomogram. Results Gender, smoking and spiculation were all clinically relevant independent predictors for LVI of lung adenocarcinoma (all P<0.05), and were used to establish the clinical model. Based on GTV, GPTV₃, GPTV₆ and GPTV₉, 7, 16, 10 and 8 optimal radiomics features were selected, respectively, and GTV, GPTV₃, GPTV₆ and GPTV₉ models were constructed. The areas under the curve (AUC) of GPTV₃ model for predicting LVI of lung adenocarcinoma in the training set and validation set was 0.82 and 0.77, respectively, all higher than those of GTV (0.79, 0.72, Z=3.74, 2.62, both P<0.01), GPTV₆ (0.80, 0.72, Z=2.40, 2.06, both P<0.05) and GPTV₉ (0.77, 0.72, Z=3.03, 2.59, both P<0.01), and GPTV₃ model was selected as the best radiomics model. AUC of the combined model nomogram (0.86, 0.73, Z=2.66, 2.31, both P<0.05) and GPTV₃ model (0.82, 0.77, Z=2.23,2.54, both P<0.05) in the training set and validation set were higher than those of the clinical model (0.73, 0.61), while there was no significant difference of AUC of the combined model nomogram nor GPTV₃ model (Z=1.57, 0.88, both P>0.05). Taken 0.20-0.50 as the threshold of probability, the net benefits of the combined model nomogram and GPTV₃ model were similar, both larger than that of the clinical model. Conclusion Nomogram based on GPTV₃ radiomics features and clinical relevant independent predictors could effectively predict LVI of lung adenocarcinoma.