Correlation between dynamic contrast-enhanced MRI and quantitative histopathologic microvascular parameters in organ-confined prostate cancer.

OBJECTIVES: To correlate pharmacokinetic parameters of 3-T dynamic contrast-enhanced (DCE-)MRI with histopathologic microvascular and lymphatic parameters in organ-confined prostate cancer. METHODS: In 18 patients with unilateral peripheral zone (pT2a) tumours who underwent DCE-MRI prior to radical prostatectomy (RP), the following pharmacokinetic parameters were assessed: permeability surface area volume transfer constant (K (trans)), extravascular extracellular volume (Ve) and rate constant (K ep). In the RP sections blood and lymph vessels were visualised immunohistochemically and automatically examined and analysed. Parameters assessed included microvessel density (MVD), area (MVA) and perimeter (MVP) as well as lymph vessel density (LVD), area (LVA) and perimeter (LVP). RESULTS: A negative correlation was found between age and K (trans) and K ep for tumour (r = -0.60, p = 0.009; r = -0.67, p = 0.002) and normal (r = -0.54, p = 0.021; r = -0.46, p = 0.055) tissue. No correlation existed between absolute values of microvascular parameters from histopathology and DCE-MRI. In contrast, the ratio between tumour and normal tissue (correcting for individual microvascularity variations) significantly correlated between K ep and MVD (r = 0.61, p = 0.007) and MVP (r = 0.54, p = 0.022). The lymphovascular parameters showed only a correlation between LVA and K ep (r = -0.66, p = 0.003). CONCLUSIONS: Significant correlations between DCE-MRI and histopathologic parameters were found when correcting for interpatient variations in microvascularity. KEY POINTS: • Normal prostate tissue shows strong heterogeneity in microvascularity. • Peripheral zone prostate cancer shows increased and less heterogeneous microvascularity. • Normal and tumour tissue shows considerable variation in microvascularity between patients. • DCE-MRI should take into account the interprostatic heterogeneity of microvasculature between patients.