Assing the role of combined ultrafast breast MRI and diffusion-weighted image in predicting breast cancer prognosis: A prospective comparative study.

Abstract Background Ultrafast breast MRI derived kinetic parameters demonstrated almost equivalent efficacy to conventional DCE-MRI as a screening tool in detecting breast cancer. However, its role as prognostic imaging markers is still questionable. The aim of this study is to use ultrafast MRI-derived kinetic parameters in combination with ADC (Apparent Diffusion Coefficient) as a prognostic imaging predictor. Methods This prospective study was conducted on 82 female patients with 94 pathologically proven breast cancers. Ultrafast breast MRI was obtained using the TWIST (time-resolved angiography with stochastic trajectories) sequence. From the ultrafast sequence, MS (Maximum slope) and TTE (Time to enhancement) parameters were obtained. ADC values were derived from the DWI (diffusion-weighted image) sequence (b value = 0/ 500/1000 s/mm2). Results MS was significantly higher in grade 3 breast cancers compared to grades 1 and 2 (p-value = 0.016). On ROC curve analysis, an MS cut-off value of > 22.75%/s showed the best accuracy among the three parameters (66.3%) in predicting Ki positivity. However, ADC cut-off value < 0.84 x10-3mm2/s was the only significant predictor of HER 2 positivity among the three parameters (sensitivity = 100%, specificity = 66.7% and AUC = 0.817). On adding the two ultrafast parameters (MS and TTE) to the ADC the specificity raised to 82.2% and AUC raised to 0.850 in predicting Her2 positivity. Conclusions Adding ADC derived from DWI to the ultrafast-derived parameters can improve the overall performance of breast MRI in predicting aggressive types of breast cancers, hence predicting the patient prognosis.