TU‐CD‐BRB‐09: Prediction of Chemo‐Radiation Outcome for Rectal Cancer Based On Radiomics of Tumor Clinical Characteristics and Multi‐Parametric MRI

Abstract

Purpose:To evaluate the tumor clinical characteristics and quantitative multi‐parametric MR imaging features for prediction of response to chemo‐radiation treatment (CRT) in locally advanced rectal cancer (LARC).Methods:Forty‐three consecutive patients (59.7±6.9 years, from 09/2013 – 06/2014) receiving neoadjuvant CRT followed by surgery were enrolled. All underwent MRI including anatomical T1/T2, Dynamic Contrast Enhanced (DCE)‐MRI and Diffusion‐Weighted MRI (DWI) prior to the treatment. A total of 151 quantitative features, including morphology/Gray Level Co‐occurrence Matrix (GLCM) texture from T1/T2, enhancement kinetics and the voxelized distribution from DCE‐MRI, apparent diffusion coefficient (ADC) from DWI, along with clinical information (carcinoembryonic antigen CEA level, TNM staging etc.), were extracted for each patient. Response groups were separated based on down‐staging, good response and pathological complete response (pCR) status. Logistic regression analysis (LRA) was used to select the best predictors to classify different groups and the predictive performance were calculated using receiver operating characteristic (ROC) analysis.Results:Individual imaging category or clinical charateristics might yield certain level of power in assessing the response. However, the combined model outperformed than any category alone in prediction. With selected features as Volume, GLCM AutoCorrelation (T2), MaxEnhancementProbability (DCE‐MRI), and MeanADC (DWI), the down‐staging prediciton accuracy (area under the ROC curve, AUC) could be 0.95, better than individual tumor metrics with AUC from 0.53–0.85. While for the pCR prediction, the best set included CEA (clinical charateristics), Homogeneity (DCE‐MRI) and MeanADC (DWI) with an AUC of 0.89, more favorable compared to conventional tumor metrics with an AUC ranging from 0.511–0.79.Conclusion:Through a systematic analysis of multi‐parametric MR imaging features, we are able to build models with improved predictive value over conventional imaging or clinical metrics. This is encouraging, suggesting the wealth of imaging radiomics should be further explored to help tailor the treatment into the era of personalized medicine.This work is supported by the National Science Foundation of China (NSFC Grant No. 81201091), National High Technology Research and Development Program of China (863 program, Grant No. 2015AA020917), and Fund Project for Excellent Abroad Scholar Personnel in Science and Technology.