Published online May 7, 2020. doi: 10.3748/wjg.v26.i17.2082
Peer-review started: February 6, 2020
First decision: February 29, 2020
Revised: March 26, 2020
Accepted: April 15, 2020
Article in press: April 15, 2020
Published online: May 7, 2020
Processing time: 91 Days and 3.1 Hours
It is evident that an accurate evaluation of T and N stage rectal cancer is essential for treatment planning. It has not been extensively investigated whether texture features derived from diffusion-weighted imaging (DWI) images and apparent diffusion coefficient (ADC) maps are associated with the extent of local invasion (pathological stage T1-2 vs T3-4) and nodal involvement (pathological stage N0 vs N1-2) in rectal cancer.
To predict different stages of rectal cancer using texture analysis based on DWI images and ADC maps.
One hundred and fifteen patients with pathologically proven rectal cancer, who underwent preoperative magnetic resonance imaging, including DWI, were enrolled, retrospectively. The ADC measurements (ADCmean, ADCmin, ADCmax) as well as texture features, including the gray level co-occurrence matrix parameters, the gray level run-length matrix parameters and wavelet parameters were calculated based on DWI (b = 0 and b = 1000) images and the ADC maps. Independent sample t-tests or Mann-Whitney U tests were used for statistical analysis. Multivariate logistic regression analysis was conducted to establish the models. The predictive performance was validated by receiver operating characteristic curve analysis.
Dissimilarity, sum average, information correlation and run-length nonuniformity from DWIb=0 images, gray level nonuniformity, run percentage and run-length nonuniformity from DWIb=1000 images, and dissimilarity and run percentage from ADC maps were found to be independent predictors of local invasion (stage T3-4). The area under the operating characteristic curve of the model reached 0.793 with a sensitivity of 78.57% and a specificity of 74.19%. Sum average, gray level nonuniformity and the horizontal components of symlet transform (SymletH) from DWIb=0 images, sum average, information correlation, long run low gray level emphasis and SymletH from DWIb=1000 images, and ADCmax, ADCmean and information correlation from ADC maps were identified as independent predictors of nodal involvement. The area under the operating characteristic curve of the model reached 0.802 with a sensitivity of 80.77% and a specificity of 68.25%.
Texture features extracted from DWI images and ADC maps are useful clues for predicting pathological T and N stages in rectal cancer.
Core tip: This retrospective study investigated the correlations between stages of rectal cancer and texture features from diffusion-weighted images and apparent diffusion coefficient maps. The area under the operating characteristic curve reached 0.793 for identifying local invasion (T stage), and reached 0.802 for determining nodal involvement (N stage). Texture analysis based on diffusion-weighted images and apparent diffusion coefficient maps showed potential value in classifying N and T stage rectal cancer.