3.0 T multiparametric prostate MRI using pelvic phased-array coil: Utility for tumor detection prior to biopsy

Rosenkrantz AB et al. – Magnetic resonance imaging had weaker specificity for prediction of a subsequent positive biopsy, as well as weaker sensitivity for tumor on a per–lobe basis, indicating that in patients with a positive MRI result, tissue sampling remains necessary for confirmation of the diagnosis as well as for treatment planning.

Methods

• Forty-two patients without biopsy-proven cancer and who underwent MRI were included.
• In all patients, MRI was performed at 3T using a pelvic phased-array coil and included T2-weighted imaging, diffusion-weighted imaging, and dynamic contrast-enhanced imaging.
• Thirteen had undergone no previous biopsy, and 29 had undergone at least 1 previous negative biopsy.
• All patients underwent prostate biopsy following MRI.
• Two fellowship-trained radiologists in consensus reviewed all cases and categorized each lobe as positive or negative for tumor.
• These interpretations were correlated with findings on post-MRI biopsy.

Results

• Follow-up biopsy was positive in 23 lobes in 15 patients (36% of study cohort).
• On a per-patient basis, MRI had a sensitivity of 100%, specificity of 74%, positive predictive value (PPV) of 68%, and negative predictive value (NPV) of 100%.
• On a per-lobe basis, MRI had a sensitivity of 65%, specificity of 84%, PPV of 60%, and NPV of 86%.
• There was a nearly significant association between Gleason score and tumor detection on MRI (P = 0.072).

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