Application of Texture Analysis Based on Sagittal Fat-Suppression and Oblique Axial T2-Weighted Magnetic Resonance Imaging to Identify Lymph Node Invasion Status of Rectal Cancer.

Lirong Song,Jiandong Yin

doi:10.3389/fonc.2020.01364

Abstract

Objective: To investigate the value of texture features derived from T2-weighted magnetic resonance imaging (T2WI) for predicting preoperative lymph node invasion (N stage) in rectal cancer.Materials and Methods: One hundred and eighty-two patients with histopathologically confirmed rectal cancer and preoperative magnetic resonance imaging were retrospectively analyzed, who were divided into high (N1-2) and low N stage (N0). Texture features were calculated from histogram, gray-level co-occurrence matrix, and gray-level run-length matrix from sagittal fat-suppression and oblique axial T2WI. Independent sample t-test or Mann-Whitney U-test were used for statistical analysis. Multivariate logistic regression analysis was conducted to build the predictive models. Predictive performance was evaluated by receiver operating characteristic (ROC) analysis.Results: Energy (ENE), entropy (ENT), information correlation (INC), long-run emphasis (LRE), and short-run low gray-level emphasis (SRLGLE) extracted from sagittal fat-suppression T2WI, and ENE, ENT, INC, low gray-level run emphasis (LGLRE), and SRLGLE from oblique axial T2WI were significantly different between stage N0 and stage N1-2 tumors. The multivariate analysis for features from sagittal fat-suppression T2WI showed that higher SRLGLE and lower ENE were independent predictors of lymph node invasion. The model reached an area under ROC curve (AUC) of 0.759. The analysis for features from oblique axial T2WI showed that higher INC and SRLGLE were independent predictors. The model achieved an AUC of 0.747. The analysis for all extracted features showed that lower ENE from sagittal fat-suppression T2WI and higher INC and SRLGLE from oblique axial T2WI were independent predictors. The model showed an AUC of 0.772.Conclusions: Texture features derived from T2WI could provide valuable information for identifying the status of lymph node invasion in rectal cancer.

Highlights

Colorectal cancer is the fifth leading cause of cancer-related mortality in China, and rectal cancer accounts for ∼30–35% of colorectal cancer cases [1, 2]
Energy (ENE), entropy (ENT), information correlation (INC), long-run emphasis (LRE), and short-run low gray-level emphasis (SRLGLE) extracted from sagittal fat-suppression T2-weighted magnetic resonance imaging (T2WI), and ENE, ENT, INC, low gray-level run emphasis (LGLRE), and SRLGLE from oblique axial T2WI were significantly different between stage N0 and stage N1-2 tumors
The analysis for features from oblique axial T2WI showed that higher INC and SRLGLE were independent predictors

Summary

Introduction

Colorectal cancer is the fifth leading cause of cancer-related mortality in China, and rectal cancer accounts for ∼30–35% of colorectal cancer cases [1, 2]. The status of lymph node invasion (as N stage) is an important prognostic factor for local recurrence and overall survival [3]. The National Comprehensive Cancer Network rectal cancer guidelines recommend neoadjuvant chemoradiotherapy (NAT) for patients with lymph node invasion before surgery [4]. Preoperative identification of lymph node invasion status in patients with rectal cancer is crucial for tailoring treatment strategies. High-resolution magnetic resonance imaging (MRI) is strongly recommended by the American Society of Colon and Rectal Surgeons before treatment because of its ability to non-invasively evaluate the microcirculation of tumors [4, 5]. More advanced and reliable techniques may be important for identifying the status of lymph node invasion with rectal MRI images

Methods

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Discussion

Conclusion