Value Of MRI Morphological, Clinicopathological And Textural Features In Predicting The Efficacy Of Neoadjuvant Chemoradiotherapy In Rectal Cancer

Objective: To investigate the predictive factors associated with pathological complete response(PCR)after neoadjuvant chemoradiotherapy(nCRT)for locally advanced rectal cancer(LARC).Methods: The retrospective study involved 153 patients with locally advanced rectal cancer who received neoadjuvant chemoradiotherapy followed by surgery in Hunan Cancer Hospital from February 2014 to December 2018.According to the postoperative pathological results,the patients were divided into pCR group and non-pCR group to identify clinical factors associated with pCR.Results: Among 153 patients,31(20.3%)achieved pCR after neoadjuvant chemoradiotherapy.Univariate analysis showed that the level of CEA before nCRT was less than 5 ug/L(P=0.028)were significantly with pCR.While many factors were not associated with pCR,such asthe level of CEA after nCRT,the time interval between neoadjuvant chemoradiotherapy and surgery,maximum tumor diameter,tumor occupation of the bowellumen,et al.Conclusion: Patients with low CEA level before nCRT is more likely to achieve pCR after neoadjuvant chemoradiotherapy for locally advanced rectal cancer.Objective: To explore the performance of texture features based on T2 WI images for predicting the pathological complete response(PCR)to neoadjuvant chemoradiotherapy(nCRT)in locally advanced rectal cancer(LARC).Method: Totally 58 patients with LARC confirmed by postoperative pathology were retrospectively analyzed.Ma Zda software was used to manually draw ROI on the maximum level of tumor on pre-nCRT and post-nCRT T2 WI images,and then nine first-order texture features(including Mean,Kurtosis,Skewness,Variance,Perc 1%,Perc10% 、 Perc 50% 、 Perc 90% 、 Perc 99%)and eleven gray level co-occurrence matrix texture features(including Ang Sc Mom,Contrast,Correlat,Dif Entrp,Dif Varnc,Entropy,Inv Df Mom,Sum Averg,Sum Entrp,Sum Of Sqs,Sum Varnc)were extracted respectively.The texture features of each time point were statistically analyzed,and the differences of texture features between pCR and non-pCR groups were compared respectively.Results: The pre-Correlat,Inv Df Mom,Sum Entrp,Dif Entrp,Dif Varnc,Entropy,Ang Sc Mom and the post-Variance,Perc 90%,Perc99%,Contrast,Sum Ofsqs,Inv Df Mom,Sum Averg,Sum Varnc,Sum Entrp,Dif Entrp,Dif Varnc,Entropy differences between pCR and non-pCR were statistically significant.The area under the ROC curve(AUC)values for the predictors in univariate analysis ranged from 0.632 to 0.835 at the pre-nCRT stage,and the AUC values ranged from 0.665 to 0.833 at the post-nCRT stage.The results revealed that Dif Varnc and Dif Entrp value indicated the best efficacy for the diagnosis of pCR at each time point respectively.In multivariate Logistic regression analysis on pre-nCRT,pre-Dif Entrp(P=0.005)was the independent predictor to pCR,with an AUC of 0.833.Post-Dif Entrp(P=0.004)was the independent predictor to pCR in the multivariate models based on the combination of the first-order and GLCM TFs,with an AUC of 0.852.Conclusions: Texture features based on T2 WI may be potential to predict the pathological complete response of LARC receiving nCRT.The Dif Entrp is texture parameters having higher predictive ability.The post-nCRT stage is the best time of prediction.