Multimodal MRI For Predicting The Efficacy Of Neoadjuvant Chemotherapy For Breast Cancer And Its Correlation With Molecular Subtype

Objective: To investigate the efficacy of multimodal MR(DWI,DCE-MRI,T2mapping)imaging techniques in evaluating the efficacy of neoadjuvant chemotherapy for breast cancer,and to provide earlier and more sensitive indicators for clinical treatment decision-making.Materials and methods: 15 patients with breast cancer undergoing neoadjuvant chemotherapy were prospectively studied.All of them had complete MRI DWI,DCE-MRI and T2 mapping images and their parameters before and after two courses of treatment,as well as pathological evaluation after chemotherapy.The changes of ADC value,dynamic enhancement curve type,maximum tumor diameter and T2 relaxation time before and after two courses of chemotherapy were observed and compared with the results of pathological evaluation(divided into MHR group and nmhr group).ADC value,T2 value and maximum tumor diameter before and after NAC were measured data.Paired sample t-test was used for difference test,and the difference was statistically significant(P<0.05);The change of dynamic enhancement curve type was count data.Chi square test was used for difference test,and the difference was statistically significant(P < 0.05).Results: the final pathological results after NAC were MHR(CR+PR)in 11 cases and NMHR(SD+PD)in 4 cases.Results of each observation index:(1)response of ADC value to chemotherapy: the change rates of ADC in the two groups before and after NAC were 0.38 ± 0.25 and 0.26 ± 0.69 respectively,and the difference was statistically significant(P=0.001).(2)Response of tumor maximum diameter(RECIST evaluation)to chemotherapy: the change rates of tumor maximum diameter before and after NAC were 0.26 ± 0.18 and 0.39 ± 0.17 respectively,with no significant difference(P=0.47),while the change values of tumor maximum diameter before and after NAC were 1.01 ± 0.67 and 1.93 ± 0.85 respectively,with significant difference(P= 0.048).(3)Response of MR enhanced tic curve type to chemotherapy:after neoadjuvant chemotherapy,the curve type of 13 lesions in 15 cases of breast cancer was degraded,and the degradation rate was 86.6%,the difference was statistically significant(P=0.02).Taking the pathological evaluation as the gold standard,the ADC change value,the change value of the maximum diameter of the focus,the curve change and the ROC curve before and after two courses of chemotherapy were measured.The sensitivity was 91%,55% and 100% respectively.The specificity was 100%,100% and 73%,respectively.The areas under the curve are 0.98,0.89 and 0.80 respectively.Conclusion: before and after neoadjuvant chemotherapy,the ADC value,the type of MR dynamic enhancement curve and the change of tumor maximum diameter all change,but the change value of ADC is the most sensitive and specific to predict the curative effect of NAC,followed by the enhancement curve,which is better than the traditional measurement of tumor diameter.Objective: To investigate the MR plain scan morphology and DCE-MRI(dynamic enhanced MR)imaging features of different molecular subtypes of breast cancer,so as to provide noninvasive diagnostic basis for molecular subtypes of breast cancer.Materials and methods: from November 2020 to January 2022,84 patients with breast lesions who underwent MR plain scan and DCE,followed by mastectomy and molecular pathological results were selected retrospectively.There were 61 cases of invasive carcinoma and 23 cases of non-invasive carcinoma.The molecular pathological results of 84 cases were divided into four types: luminala in 24 cases(29%),luminalb in 48 cases(57%),HER-2 overexpression in 5 cases(6%),and triple negative type in 7 cases(8%),among which luminalb breast cancer accounted for the highest proportion.MR image analysis of 84 cases was evaluated according to the standard of breast imaging reporting and data system(BI-RADS).Results: among the lesions with ring enhancement,the proportion of triple negative breast cancer(42.9%)was higher than that of other molecular types of breast cancer.This study found that the main enhancement mode of luminal-b was uneven enhancement(89.6%),while the main enhancement mode of triple negative breast cancer was ring enhancement(57.1%).There was significant difference in enhancement mode between luminal-b and triple negative breast cancer(P=0.007).Luminal-a breast cancer: on MR images,the lesions showed regular morphology(54.2%),with lobulated edges(50%),uneven enhancement(87.5%),and dynamic enhancement curve(66.7%);Luminal-b breast cancer: on MR images,the lesions showed regular morphology(54.2%),lobulated edges(62.5%),uneven enhancement(89.6%),and dynamic enhancement curve type III(66.7%);HER-2 type breast cancer:the lesions were irregular in shape(100%),with smooth or lobulated edges(40%),with uneven enhancement(80%),and the dynamic enhancement curve was type III(80%).In Sanyin type breast cancer,the lesions were regular in shape(71.4%),with lobulated edges(71.4%);Strengthening mode: Ring strengthening(42.9%);The curve type is type III curve(100%).Conclusion: there are some differences between Mr plain scan and DCE-MRI images of different molecular types,especially the three yin type of breast cancer.The application of Mr plain scan and DCE-MRI morphology to evaluate the preoperative molecular subtypes can provide some noninvasive diagnostic information for the choice of clinical treatment.However,due to the overlap between various types,the value is limited and is only for reference.