[Evaluation of pathologic response of breast cancer to neoadjuvant chemotherapy with magnetic resonance diffusion weighted imaging].

This paper aims to investigate the value of diffusiion weighted imaging (DWI) and different apparent diffusion coefficient (ADC) methods to predict the curative effects of neoadjuvant chempotherapy (NAC) for breast cancer. From March 2010 to December 2012, seventy-one patients were pathologically confirmed invasive breast cancer by needle puncture biopsy received before surgery, and underwent magnetic resonance before and after NAC, the ADC were measured by mean ADC method and lower ADC method. The pathologic response after NAC was divided to major histological response (MHR) group and non-major histological response (NMHR) group according to Miller & Payne system. Results displayed that ADC values obtained before NAC, at the end of the second cycle of NAC, and after whole course of treatment, had good correlations between mean and lower ADC methods (the Pearson's correlation=0.699, 0.749 and 0.895, respectively). Significant difference in ADC obtained both with mean and lower ADC methods could be found between MHR and NMHR groups after the second cycle of NAC (P< 0.05). After the second cycle of NAC, significant difference in the change rate of ADC could be found between MHR and NMHR groups by using lower ADC method (P<0.05), but not be found by using mean ADC method (P >0.05). In conclusion, DWI could monitor the pathologic changes of breast cancer after NAC, and the lower ADC method might be used to evaluate the curative effect of NAC with the change rate of ADC.