The Locally advanced rectal cancer (LARC) patients were routinely treated with neoadjuvant chemoradiotherapy (CRT)
firstly and received total excision afterwards. While, the LARC patients might relieve to T1N0M0/T0N0M0 stage after
the CRT, which would enable the patients be qualified for local excision. However, accurate pathological TNM stage
could only be obtained by the pathological examination after surgery. We aimed to conduct a Radiomics analysis of
Diffusion weighted Imaging (DWI) data to identify the patients in T1N0M0/T0N0M0 stages before surgery, in hope of
providing clinical surgery decision support. 223 routinely treated LARC patients in Beijing Cancer Hospital were
enrolled in current study. DWI data and clinical characteristics were collected after CRT. According to the pathological
TNM stage, the patients of T1N0M0 and T0N0M0 stages were labelled as 1 and the other patients were labelled as 0.
The first 123 patients in chronological order were used as training set, and the rest patients as validation set. 563 image
features extracted from the DWI data and clinical characteristics were used as features. Two-sample T test was conducted to pre-select the top 50% discriminating features. Least absolute shrinkage and selection operator
(Lasso)-Logistic regression model was conducted to further select features and construct the classification model. Based
on the 14 selected image features, the area under the Receiver Operating Characteristic (ROC) curve (AUC) of 0.8781,
classification Accuracy (ACC) of 0.8432 were achieved in the training set. In the validation set, AUC of 0.8707, ACC
(ACC) of 0.84 were observed.