乳腺癌新辅助化疗前后正常乳腺腺体MRI表观扩散系数的对比研究

目的探讨新辅助化疗(NAC)对乳腺癌患者正常乳腺腺体MRI的表观扩散系数(ADC)的影响。方法选取已确诊为乳腺癌并行NAC者16例,收集其NAC前、NAC第2个周期后及第4个周期后MRI图像,分别测量健侧乳腺乳晕后方实质(正常纤维腺体)的ADC值。对NAC前、NAC第2个周期后及第4个周期后正常腺体的ADC值进行配对t检验和线性回归分析。结果 NAC前、NAC第2个周期后及第4个周期后正常腺体的ADC值依次增高,分别为(1.56±0.35)×10-3mm2/s、(1.64±0.35)×10-3mm2/s和(1.75±0.33)×10-3mm2/s;其中NAC前与NAC第4个周期后、NAC第2个周期后与NAC第4个周期后比较差异有统计学意义(P<0.05);正常腺体的ADC值与化疗进展周期数具有线性关系。结论乳腺癌NAC可使正常乳腺腺体的ADC值升高,而这种效应可能随着化疗周期数增多而表现更明显。

Comparison of apparent diffusion coefficient in normal breast before and after neoadjuvant chemotherapy

Objective To investigate the change of apparent diffusion coefficient （ADC） value on magnetic resonance diffusion-weight imaging （DWI） in the normal breast before and after neoadjuvant chemotherapy （NAC）. Methods Sixteen patients with pathologically confirmed locally advanced breast cancer treated with NAC protocol （paclitaxel and adriamycin, TA） were enrolled in this study. They all finished four courses of NAC and underwent preoperative breast MRI three times （before chemotherapy, after two courses and four courses of NAC respectively）. Each time the ADC value of the cancer and contralateral normal breast tissue were measured, and paired t test and linear regression analysis were used for statistical analysis. Results The average ADC values of the normal breasts were （1.56 ±0.35）×10^-3mm^2/s before chemotherapy, （1.64 ±0.35）×10^-3mm^2/s after two courses of NAC and （1.75 ±0.33）×10^-3mm^2/s after four courses of NAC. The ADC values of the third time were higher than the second and the first time （P〈0.05）, while the ADC values between the first and the second time had no significant difference. Furthermore, linear regression analysis showed that the slope rate was positive. Conclusion After several courses of neoadjuvant chemotherapy, the ADC value of the normal breast contralateral to the cancer side will increase, and the effects might be more significant if more courses were taken.