Relationship between histogram metrics of pharmacokinetic parameters of DCE-MRI and histological phenotype in breast cancer

Background To investigate the correlation between quantitative pharmacokinetic parameters and clinicopathological prognostic biomarkers including estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), and MiB1 (Ki-67) in patients with breast cancer, the image histogram analysis was performed on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). Methods The reference region model (RRM) was used to calculate the quantitative permeability parameters, including reference region volume transfer constant (Ktrans,RR), the rate constant of tissue of interest (Kep,TOI), and the rate constant of reference region (Kep,RR). Histogram analysis was performed to compare these parameters between ER/PR/HER2/Ki-67 positive and negative groups. The performance of the histogram parameters Ktrans,RR, Kep,TOI and Kep,RR in differential diagnosis of immunohistochemistry results was conducted by receiver operating characteristic (ROC) curve analysis. Results All the histogram metrics of Kep,TOI significantly differed between ER/PR positive and negative groups (P0.05). The 10th percentile, energy, entropy and variance of Ktrans,RR, and almost all the histogram parameters of Kep,TOI except for variance significantly differed between HER2 positive and negative groups (all P