Combination of Multiparametric Magnetic Resonance Imaging With Elastic-fusion Biopsy Has a High Sensitivity in Detecting Clinically Significant Prostate Cancer in Daily Practice.

BACKGROUND

The index lesion (IL) is the largest cancer focus, usually harbors the highest grade, and might drive the history of prostate cancer (PCA). Multiparametric magnetic resonance imaging (mp-MRI) has a high negative predictive value in ruling out clinically significant (cs)PCA. We aimed evaluating the efficiency of mp-MRI and targeted biopsy in detecting csPCA and the concordance between the MRI index lesion (MRI-IL) and the presence of csPCA inside it.

MATERIALS AND METHODS

We retrospectively evaluated 158 men who underwent prostate biopsy after a positive pre-biopsy mp-MRI scan. All mp-MRI lesions were biopsied using a transrectal ultrasound elastic-fusion approach (2-4 targeted plus 10-12 random systematic biopsies). csPCA was defined as grading group ≥ 2 or > 3 cores with cancer or ≥ 50% of core involved by tumor.

RESULTS

mp-MRI detected 158 ILs and 46 non-ILs. One hundred were Prostate Imaging-Reporting and Data System version 2 (PI-RADS v2) score 3, 84 score 4, and 20 score 5. csPCA was found in 63.9% of the MRI-ILs. Eighty percent of detected cancer using mp-MRI and targeted biopsy was clinically significant. Eighty-seven percent of the transitional zone lesions were clinically non-significant or negative for cancer. The probability of detecting csPCA increases with increasing size of MRI-IL, and every extra millimeter raises the odds of detecting csPCA of 12.2%. All PI-RADS v2 score lesions showed a strong association with csPCA. The risk of matching between MRI-IL and csPCA inside it increases by 36.2% as the total percentage of cancer in all cores increases.

CONCLUSIONS

mp-MRI showed high sensitivity in detecting csPCA in the peripheral zone, with concordance between MRI-IL and csPCA.