D'Amico risk stratification correlates with degree of suspicion of prostate cancer on multiparametric magnetic resonance imaging.

PURPOSE: We determined whether there is a correlation between D'Amico risk stratification and the degree of suspicion of prostate cancer on multiparametric magnetic resonance imaging based on targeted biopsies done with our electromagnetically tracked magnetic resonance imaging/ultrasound fusion platform. MATERIALS AND METHODS: A total of 101 patients underwent 3 Tesla multiparametric magnetic resonance imaging of the prostate, consisting of T2, dynamic contrast enhanced, diffusion weighted and spectroscopy images in cases suspicious for or with a diagnosis of prostate cancer. All prostate magnetic resonance imaging lesions were then identified and graded by the number of positive modalities, including low-2 or fewer, moderate-3 and high-4 showing suspicion on multiparametric magnetic resonance imaging. The biopsy protocol included standard 12-core biopsy, followed by real-time magnetic resonance imaging/ultrasound fusion targeted biopsies of the suspicious magnetic resonance lesions. Cases and lesions were stratified by the D'Amico risk stratification. RESULTS: In this screening population 90.1% of men had a negative digital rectal examination. Mean±SD age was 62.7±8.3 years and median prostate specific antigen was 5.8 ng/ml. Of the cases 54.5% were positive for cancer on protocol biopsy. Chi-square analysis revealed a statistically significant correlation between magnetic resonance suspicion and D'Amico risk stratification (p<0.0001). Within cluster resampling demonstrated a statistically significant correlation between magnetic resonance suspicion and D'Amico risk stratification for magnetic resonance targeted core biopsies and magnetic resonance lesions (p<0.01) CONCLUSIONS: Our data support the notion that using multiparametric magnetic resonance prostate imaging one may assess the degree of risk associated with magnetic resonance visible lesions in the prostate.