| Objective:To investigate correlation between histogram parameters of apparent diffusion coefficient?ADC?of multi-b-value diffusion-weighted imaging and molecular subtypes and prognostic factors of breast cancer,and to evaluate the diagnostic performance of ADC histogram among different b values.Methods:A total of 114 patients?116 lesions?with invasive ductal carcinomas confirmed by surgical pathology who underwent breast multi-b-value diffusion-weighted-MRI from March 2015 to January 2016 in Tianjin Medical University Cancer Institute and Hospital were analyzed retrospectively.The histograms of ADC with b value of 500,800,1000,1500s/mm2 were generated by Image J software.Various parameters were calculated,including ADCmin,ADCmean,ADCmedian,ADCstd,ADCmode,ADCmax,skewness,and kurtosis.The tumor size,histological grade,lymph node status,expression of ER,PR,Her-2,and Ki-67 were recorded.All lesions were divided into different groups based on molecular subtypes?Luminal A,Luminal B,Her-2 over-expression,and triple-negative?,tumor sizes?T1 vs.T2T3?,histologic grades?high vs.low?,lymph node status?positive vs.negative?.The differences of ADC histogram parameters among four molecular subtypes were compared by Kruskal-Wallis H-tests.Mann-Whitney U-tests were used to compare differences of histogram parameters between two groups under each classification,and Spearman rank correlation analysis were conducted.Receiver operating characteristic?ROC?curve were constructed.Area under curve?AUC?were compared between parameters with statistical difference.Results:Among 116 lesions,24 lesions were Luminal A,58 lesions were Luminal B,16 lesions were Her-2 over-expression subtype,and triple-negative breast cancer were18 lesions.Under all b values of 500,800,1000,1500 s/mm2,there were significant differences in ADCmeanean and ADCminin among the four groups?P<0.05?.The ADCmeanean and ADCminin were highest in Luminal A breast cancer,followed by Her-2over-expression subtype,triple-negative subtype.And Luminal B breast cancer has lowest ADCmeanean and ADCmin.With b values of 500,800,1000 and 1500s/mm2,the skewness of Luminal subtype were 0.281,0.316,0.258,0.400,while non-Luminal subtype's skewness were 0.598,0.542,0.534,0.817.The skewness were lower in Luminal subtype than that in non-Luminal subtype?P<0.05?.With all b values,ADCminin values in Her-2 over-expression group were 0.808×10-3mm2/s,0.829×10-3mm2/s,0.764×10-33 mm2/s,0.738×10-3mm2/s,and ADCminin values in non-Her-2 over-expression group were 0.698×10-3mm2/s,0.695×10-3mm2/s,0.668×10-3mm2/s,0.610×10-3mm2/s.The ADCminin were higher in Her-2 over-expression group than that in non-Her-2 over-expression group?P<0.05?.There were no significant differences in terms of ADC histogram parameters between the triple-negative breast cancer and the non-triple-negative breast cancer?P>0.05?.With b values of 500,800,1000,1500s/mm2,kurtosis in stage T1 tumor were 0.115,0.069,0.042,0.390,and that of T2T3tumor were 0.780,0.390,0.442,1.310.The kurtosis is lower in stage T1 tumor than that of T2T3 tumor?P<0.05?.The kurtosis was correlated to tumor size?r=0.227,0.133,0.243,0.307,P<0.05?.ADCmodeode and ADCmeanean were higher in lower histologic grades than that of higher histologic grades with b value of 500 s/mm2(0.961×10-3mm2/s vs.0.860×10-3mm2/s,1.031×10-33 mm2/s vs.0.994×10-3mm2/s,P=0.020,0.030).There were no significant differences between ADC histogram parameters of lymph node positive group and lymph node negative group.Under different b values,there were no significant differences in terms of AUC for each histogram parameters which were statistically significantly differences?P>0.05?.Conclusion:Multi-b-value DWI ADC histogram analysis,as a quantitative method to characterize tumor heterogenetity,to some exent can reflect the biological behavior characteristics and prognosis of breast cancer.Luminal A breast cancer has the highest ADC value,followed by Her-2 over-expression subtype and triple-negative subtype.Luminal B breast cancer has the lowest ADC value.ADC histogram parameters have potential value in evaluating T stage and histological grade of breast cancer.The distribution of ADC values in breast cancer with higher T stage is more concentrated.Lower histological grade breast cancer showed a higher ADC value. |
PDF Full Text Request