Research Of Ultrasonic Superb Microvascular Imaging In Evaluating The Efficiency Of Neoadjuvant Chemotherapy For Breast Cancer

Objectives:Superb microvascular imaging(SMI)was applied to compare and research the vascularization indexes of lesions between the group with significant pathological responses and the group with non-significant pathological responses before and after neoadjuvant chemotherapy(NAC)for breast cancer,and to discuss the role of SMI in diagnosing of NAC resistance for breast cancer.To compare the detection ability of blood flow between SMI and color Doppler flow imaging(CDFI)before and after NAC.To explain the diagnostic value of SMI in the efficacy evaluation for breast NAC by analyzing the diagnostic efficiency of SMI combined with two dimensional(2D)grey scale ultrasound in determining the breast cancer chemotherapy resistance.Materials and methods:38 patients diagnosed as breast cancer in our hospital and underwent NAC and surgery from August 2020 to January 2023 were recruited into the study,with a total of 39 lesions,who were retrospectively analyzed and all lesions underwent SMI,CDFI and conventional 2D grey scale ultrasound examinations before NAC and after the end of whole NAC treatment.The lesions in significant pathological responses group as well as non-significant pathological responses group were decided by pathological results after surgery,and the maximum diameter of 2D grey scale ultrasound and vascular index(VI)of SMI from lesions in the two groups were measured respectively before NAC and after the end of whole NAC treatment,and the information of vascular grading,vascular morphology,vascular distribution and penetrating vessels on SMI as well as CDFI from the plane with the richest blood were recorded.The quantitative indexes(VI value)and qualitative indexes(the grading,morphology,distribution and penetration)of breast cancer lesions were compared between lesions in significant pathological responses group and those in non-significant pathological responses group pre-and-post NAC.The efficiency of VI decrease rate pre-and-post NAC in diagnosing chemotherapy resistance was analyzed by using the pathology as gold standard,and the consistency of VI decrease rate with pathology results was examined.The ability of SMI and CDFI for detecting blood flow of the 39 breast cancer lesions was compared pre-and-post NAC.The efficiency of 2D grey scale ultrasound,SMI and the bimodal ultrasound with 2D grey scale ultrasound combined SMI for diagnosing NAC resistance in breast cancer was compared by painting ROC,and the net reclassification index(NRI)was used to analyze whether bimodal ultrasound could improve the efficiency of 2D grey scale ultrasound or SMI alone in assessing the NAC.Results:(1)39 breast cancer lesions were graded according to pathological MP criteria,G1: 9 lesions,G2: 8 lesions,G3:8 lesions,G4:4 lesions,and G5:10 lesions.There were 22 lesions in significant pathological response group and 17 lesions in nonsignificant pathological response group.(2)There was no statistically significant difference in VI value between lesions in significant pathological response group and those in non-significant pathological response group before NAC(P>0.05),but statistically significant difference was found in VI value between two groups after NAC(P<0.05).(3)AUC of VI value decreased rate in breast cancer pre-and-post NAC for diagnosing NAC resistance was 0.842,with sensitivity of 94.12% and specificity of 72.73%(P<0.05).Using the VI decrease rate of 76.65% as diagnostic threshold,the VI decrease rate was good concordant with pathology results for Kappa value of 0.647(P<0.05).(4)In the SMI mode,there was no statistical difference in vascular characteristic between the lesions in significant pathological response group and those in non-significant pathological response group before NAC(P>0.05).After NAC,the vascular grading of lesions in significant pathological response group was mainly lack of blood supply(grading Adler 0,I),vascular morphology was mainly simple type(no blood flow,dot-like or linear),and the detection rate of penetrating vessels was low,which were statistically different from vascular characteristics of lesions in non-significant pathological response group(P>0.05),and there was no statistically significant difference in the vascular distribution characteristic between the two groups after NAC(P>0.05).(5)The SMI detection rates of the 39 lesions were higher than those of CDFI in high vascular grading(Adler II,III),complex vascularity(branching,tortuous),central distributed blood and penetrating flow(P<0.05).(6)The AUC value(0.807)in the diagnosis of NAC resistance in breast cancer,sensitivity(76.47%)and specificity(90.91%)of bimodal ultrasound with 2D combined SMI were higher than those of 2D grey scale ultrasound(AUC: 0.697,sensitivity: 64.71%,specificity: 72.73%)and SMI(AUC: 0.761,sensitivity: 70.59%,specificity:68.18%),although the difference was not significant(P> 0.05),the NRI comprehensively considering sensitivity and specificity showed that the diagnostic efficiency of bimodal ultrasound was significantly improved compared with that of2 D grey scale ultrasound and SMI alone,and the correct reclassification ratio was increased by 29.9% and 28.6% respectively(P< 0.05).Conclusions:SMI can effectively identify whether breast cancer is resistance to NAC by quantitative indexes and vascularization qualitative indexes.Compared with CDFI,SMI has advantages in terms of the detection ability for low-speed blood flow and tiny vessels before and after breast cancer NAC.The new model of 2D grey scale ultrasound combined with SMI significantly improves the ability to evaluate the efficiency of NAC in breast cancer.Therefore,SMI has important diagnostic significance in evaluating the efficiency of NAC for breast cancer.