The Value Of DCE-MRI Semi-quantitative Parameters And ADC Values In Evaluating The Efficacy Of Neoadjuvant Chemotherapy For Invasive Breast Cancer

Objective: To explore the application value of contrast-enhanced magnetic resonance imaging(DCE-MRI)semi-quantitative parameters and apparent diffusion coefficient(ADC)values in the evaluation of the efficacy of neoadjuvant chemotherapy(NAC)for invasive breast cancer.Methods: A total of 45 patients with invasive breast cancer who received neoadjuvant chemotherapy in the Second Affiliated Hospital of University of South China from October 2018 to January 2021 were collected.All patients were confirmed to be invasive breast cancer by fine needle aspiration biopsy,and then received neoadjuvant chemotherapy.All patients underwent contrast-enhanced magnetic resonance imaging and diffusion weighted imaging(DWI)examination before chemotherapy and after 2 to 4 cycles of chemotherapy,time signal intensity curve(TIC)curve and region of interest(ROI)were drew by two radiologists and obtained early enhancement rate,maximum enhancement rate,ADC values and tumor maximum diameter.According to the Miller&Payne pathological classification,the patients were divided into histologically significant response group(MHR)and histologically non-significant response group(NMHR).The maximum diameter of tumor,ADC value,TIC curve,early enhancement rate and maximum enhancement rate were compared between the two groups before and after chemotherapy.Independent sample t-test or paired sample t-test were used for measurement data conforming to normal distribution,while Mann-Whitney U test was used for measurement data not conforming to normal distribution.Chi-square test,paired chi-square test or Fisher’s exact test were used for counting data,and P<0.05 was considered statistically significant.The Med Calc software was used to draw the receiver operating curve(ROC),and the area under the curve(AUC),diagnostic threshold,specificity and sensitivity were calculated.The diagnostic efficacy of predicting the efficacy of NAC was analyzed by analyzing the maximum diameter change rate of tumor,ADC value change rate,early enhancement rate change rate and maximum enhancement rate change rate after 2-4 cycles of neoadjuvant chemotherapy.Results:(1)Before neoadjuvant chemotherapy,no significant difference was observed in the baseline parameters of tumor maximum diameter,ADC value,early enhancement rate,maximum enhancement rate between MHR and NMHR groups(P > 0.05).(2)After 2 to 4 cycles of neoadjuvant chemotherapy,comparing with the parameters before neoadjuvant chemotherapy,there was significant difference in all parameters of tumor maximum diameter,ADC value,early enhancement rate and maximum enhancement rate in MHR group were statistically significant(P< 0.05).However,the difference of tumor maximum diameter,ADC value,early enhancement rate and maximum enhancement rate in NMHR group were not statistically significant(P > 0.05).(3)After 2 to 4 cycles of neoadjuvant chemotherapy,comparing with the baseline parameters,there was significant difference in all parameters of the rate of change of maximum diameter of tumor,the rate of change of ADC value,the rate of change of early enhancement rate and the rate of change of maximum enhancement rate between MHR and NMHR groups(P < 0.05).Besides,The ROC indicated that the ADC value change rate had the largest area under the curve,which had a specificity of 88.9% and a sensitivity of 94.4%,respectively.(4)After 2 to 4 cycles of neoadjuvant chemotherapy,the outflow curve decreased,and the platform and inflow curves increased,the change of Ⅲ-Ⅰwas the main one in MHR group,the change of Ⅲ-Ⅱwas the main one in NMHR group.Before and after neoadjuvant chemotherapy,there was no significant difference in the type of TIC curve between the MHR group and the NMHR group(P < 0.05).conclusions:(1)After neoadjuvant chemotherapy,contrast-enhanced magnetic resonance imaging semi-quantitative parameters and apparent diffusion coefficient values have certain predictive value for pathological response.(2)After neoadjuvant chemotherapy,the rate of change of apparent diffusion coefficient values has exact diagnostic and prediction efficiency.