Study Of Diffusion Weighted Imaging And DCE-MRI In Evaluating The Response To Neoadjuvant Chemotherapy Of Breast Cancer

Objective: This study retrospectively analyzed the value of magnetic resonance imaging(MRI)indicators in evaluating the efficacy of breast cancer patients after neoadjuvant chemotherapy(NAC),such as the early enhancement rate of dynamic contrast-enhanced magnetic resonance curves and apparent diffusion coefficient(ADC),time-intensity curve(TIC)morphology,diffusion-weighted imaging(DWI),and changes in the maximum diameter of lesions,attempted to explore the value of high diagnostic value when magnetic resonance imaging was used for review after neoadjuvant chemotherapy in breast cancer patients.Imaging criteria.Methods: A hospital patient admitted to the Fourth Hospital of Hebei Medical University from January 2015 to June 2017 was identified as having undergone at least 4 cycles of neoadjuvant chemotherapy after diagnosis.Before and after neoadjuvant chemotherapy,breast MRI scans were performed.The pathological response was post-operative Miller-Payne(MP)grading evaluation system as the gold standard.All cases were divided into clinical improvement group(Group A)and clinical non-improvement group(Group B).Two-sample non-parametric test(Mann-Whitney U test)was used to compare the maximum lesion diameter,apparent diffusion coefficient,dynamic contrast enhancement scan early enhancement rate,and time-signal intensity curve morphology before and after neoadjuvant chemotherapy.The ROC(receiver operating characteristic)curve analysis,complete the AUC(area under curve)calculations,draws and compares the diagnostic value of various indicators.Results: After 4 cycles of neoadjuvant chemotherapy,64 of the 93 patients included in this study were clinically evaluated in group A and 29 in group B.Before chemotherapy,the MRI parameters of the two groups: maximum diameter of the lesion,ADC value,early enhancement rate of dynamic contrast enhanced scan,and time-signal intensity curve were not statistically different(P>0.05).After 4 cycles of neoadjuvant chemotherapy,the differences in the parameters between the two groups were statistically significant(P<0.05).The change rate of the maximum diameter of the lesions and the rate of change of the ADC values in the two groups before and after chemotherapy were statistically different(P<0.05).The time-signal intensity curves of the lesions before and after chemotherapy were from type III to type I.The trend of change was statistically significant(P<0.05).The enhancement rate of early enhancement contrast-enhanced scanning was generally reduced,and there was a statistically significant difference(P<0.05).The ROC curves were drawn using the rate of change of each index after neoadjuvant chemotherapy in patients in group A and group B.In addition to the rate of change in the rate of early enhancement of the dynamic contrast enhanced scan,the evaluation value of each index was higher(AUC>0.5).The highest diagnostic efficacy was the maximum lesion diameter change rate(AUC=0.97),the sensitivity was 100%,and the specificity was 86.9%.Followed by the rate of change of lesion ADC(AUC=0.901).This is followed by a change in the shape of the time-signal intensity curve(AUC=0.897).The rate of change of early enhancement rate of dynamic contrast enhanced scan was the lowest(AUC=0.745).Conclusions: The shrinking of lesions and the increase of ADC value after neoadjuvant chemotherapy in breast cancer can be regarded as the evidence of the response of lesions to chemotherapy.At the same time,the enhancement rate of early contrast enhancement scan decreases,and the time-signal intensity curve also changes.In evaluating the efficacy of neoadjuvant chemotherapy,the maximum diameter of the lesion reflects the highest accuracy of the curative effect,can reflect the efficacy in most cases;the accuracy of the lesion ADC value change rate is secondarily followed,but less than the maximum diameter measurement is convenient and reproducible.High;dynamic contrast enhanced scan early enhancement rate and time-signal intensity curve shape changes can also accurately reflect the efficacy of chemotherapy,but overall is not as accurate as the lesion maximum diameter rate and ADC value change rate.