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 ( K trans,RR ), the rate constant of tissue of interest ( K ep,TOI ), and the rate constant of reference region ( K ep,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 K trans,RR , K ep,TOI and K ep,RR in differential diagnosis of immunohistochemistry results was conducted by receiver operating characteristic (ROC) curve analysis. Results: All the histogram metrics of K ep,TOI significantly differed between ER/PR positive and negative groups (P K trans,RR and K ep,RR did not significantly differ between ER/PR positive and negative groups (P>0.05). The 10th percentile, energy, entropy and variance of K trans,RR , and almost all the histogram parameters of K ep,TOI except for variance significantly differed between HER2 positive and negative groups (all P K trans,RR significantly differed between Ki-67 positive and negative groups (P K ep,TOI showed the highest AUC of 0.977 and 0.879 in differentiating ER/PR status. The energy of K trans,RR presented the highest AUC in the differentiation of HER2 and Ki-67. Conclusions: Histogram analysis on quantitative pharmacokinetic breast parameters using DCE-MRI improves the performance in differentiation of histological phenotypes of breast cancer.