Abstract Background Radiomics may be useful in rectal cancer management. The aim of this study was to assess and compare different radiomics approaches over qualitative evaluation to predict disease-free survival (DFS) in patients with locally advanced rectal cancer treated with neoadjuvant therapy. Methods Patients from a phase II, multicentre, randomized study (GRECCAR4; NCT01333709) were included retrospectively as a training set. An independent cohort of patients comprised the independent test set. For both time points and both sets, radiomic features were extracted from two-dimensional manual segmentation (MS), three-dimensional (3D) MS, and from bounding boxes. Radiomics predictive models of DFS were built using a hyperparameters-tuned random forests classifier. Additionally, radiomics models were compared with qualitative parameters, including sphincter invasion, extramural vascular invasion as determined by MRI (mrEMVI) at baseline, and tumour regression grade evaluated by MRI (mrTRG) after chemoradiotherapy (CRT). Results In the training cohort of 98 patients, all three models showed good performance with mean(s.d.) area under the curve (AUC) values ranging from 0.77(0.09) to 0.89(0.09) for prediction of DFS. The 3D radiomics model outperformed qualitative analysis based on mrEMVI and sphincter invasion at baseline (P = 0.038 and P = 0.027 respectively), and mrTRG after CRT (P = 0.017). In the independent test cohort of 48 patients, at baseline and after CRT the AUC ranged from 0.67(0.09) to 0.76(0.06). All three models showed no difference compared with qualitative analysis in the independent set. Conclusion Radiomics models can predict DFS in patients with locally advanced rectal cancer.

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直肠癌放射组学建模预测无病生存：不同方法的评估

摘要 背景放射组学可能有助于直肠癌的治疗。本研究的目的是通过定性评估来评估和比较不同的放射组学方法，以预测接受新辅助治疗的局部晚期直肠癌患者的无病生存期 (DFS)。 方法来自 II 期、多中心、随机研究 (GRECCAR4；NCT01333709) 的患者被回顾性纳入训练集。独立的患者队列组成了独立的测试集。对于两个时间点和两个集合，从二维手动分割 (MS)、三维 (3D) MS 和边界框提取放射组学特征。DFS 的放射组学预测模型是使用超参数调整的随机森林分类器构建的。此外，将放射组学模型与定性参数进行比较，包括基线时通过 MRI (mrEMVI) 确定的括约肌侵犯、壁外血管侵犯，以及放化疗 (CRT) 后通过 MRI (mrTRG) 评估的肿瘤消退等级。 结果在 98 名患者的训练队列中，所有三种模型均表现出良好的性能，平均（sd）曲线下面积（AUC）值范围为 0.77（0.09）至 0.89（0.09），用于预测 DFS。3D 放射组学模型优于基于基线 mrEMVI 和括约肌侵犯（分别为 P = 0.038 和 P = 0.027）以及 CRT 后 mrTRG 的定性分析（P = 0.017）。在 48 名患者的独立测试队列中，基线时和 CRT 后 AUC 范围为 0.67（0.09）至 0.76（0.06）。与独立组中的定性分析相比，所有三个模型都没有显示出差异。 结论放射组学模型可以预测局部晚期直肠癌患者的 DFS。