Information of prostate biopsy positive core: does it affect MR detection of prostate cancer on using 3T-MRI?

Abstract

We assessed which information from a prostate biopsy had the strongest relationship with prostate cancer detection by 3T-MRI. Sixty-one consecutive patients with biopsy-proven prostate cancer who underwent 3T-MRI before biopsy were enrolled in this retrospective study. Two radiologists independently reviewed T2-weighted and diffusion-weighted images. When the cancer lesions were revealed by biopsy and MRI depicted them at corresponding sites, we classified these lesions as MRI-detectable cancer. If the cancer lesions were revealed by biopsy, but any cancers had not been detected, we classified these lesions as MRI-undetectable cancer. We compared the Gleason score (GS), cancer ratio (CaR) and cancer length (CaL) from core biopsies between the two groups. GS, CaR and CaL differed significantly between the MRI-detectable group (N = 70), and the MRI-undetectable group (N = 73). 3T-MRI could detect cancer cores with a sensitivity of 90.5% in cores with CaR ≥ 60%, and with a sensitivity of 81.8% in those with CaL ≥ 5 mm. Receiver operating characteristic analysis showed that CaR (P = 0.006) and CaL (P = 0.010) significantly associated with the prostate cancer detection using MRI rather than GS. CaR and CaL from the core biopsies showed a stronger relationship to detection of the prostate cancer on 3T-MRI than the GS did.