Combined diffusion-weighted and dynamic contrast-enhanced MRI for prostate cancer diagnosis - Correlation with biopsy and histopathology

Purpose: To determine whether the combination of diffusion-weighted (DW) and dynamic contrast-enhanced (DCE) MRI provides higher diagnostic sensitivity for prostate cancer than each technique alone. Materials and Methods: Fourteen patients with a clinical suspicion of prostate cancer underwent endorectal MRI on a 1.5T scanner prior to transrectal ultrasound (TRUS)guided biopsies. The average values, of the apparent: diffusion coefficient (ADC, calculated from b-values of 0 and 600), K-trans, v(e), maximum gadolinium (Gd) concentration, onset time, mean,gradient, and maximum enhancement were determined. Correlation with histology was based, on biopsy (six patients) and prostatectomy specimen (eight, patients) results. The Tukey-Kramer test was used for statistical analysis. Results: The average values of all MRI parameters; except v, and maximum Gd concentration, showed significant differences between tumor and normal prostate. The sensitivity and specificity values were respectively 54% (35-72%) and 100% (95-100%) for the ADC data, and 59% (39-77%) and 74% (63-83%) for-the DCE data. When both ADC and DCE results were combined, the sensitivity increased to 87% (68-95%) and specificity decreased to 74% (62-83%). Conclusion: All but two DW-, and DCE-MRI parameters showed significant differences between tumor and normal prostate. Combining both techniques provides better sensitivity, with a small decrease in specificity.