The diagnostic efficacy of biparametric non-contrast MRI in patients with total prostate-specific antigen level of 4-10 ng/mL: A Multi-center study
Multiparametric MRI(mpMRI) of the prostate is the imaging study of choice for patients suspected to have prostate cancer (PCa). In mpMRI, dynamic contrast-enhanced (DCE) sequence only has effect on distinguishing PI-RADS 3 and 4 lesions in the peripheral zone. Compared to mpMRI, biparametric MRI (bpMRI) excludes DCE sequence, which eliminates the possibility of cerebral deposition of gadolinium based contrast agents. Recent studies proposed that non-contrast bpMRI to be a useful diagnostic tool for PCa than contrast mpMRI. Our goal is to test if the non-constrast bpMRI a useful diagnostic tool for patients with total serum prostate-specific antigen (tPSA) level of 4-10 ng/mL.
A computerized search of our electronic medical records was performed to identify biopsy naïve patients between January 2013 and April 2017 who met the following criteria: 1) Underwent TRUS guided cognitive-fusion prostate biopsy at one of our three institutions; 2) pre-biopsy prostate MRI was performed within 3 months before the biopsy at one of our two urological cancer centers; 3) prebiopsy tPSA was 4-10ng/mL. Patients were excluded if they had previous treatment of prostate cancer (neoadjuvant chemotherapy and/ or androgen deprivation therapy). MpMRI including T2 weighted imaging, diffusion weighted imaging and DCE imaging was obtained and scored based upon PI-RADS v2. BpMRI PI-RADS score was performed using the same scale excluding DCE sequence (No upgrade of PI-RADS 3 lesions).
Among the 427 patients identified, 154 (36.1%) patients had prostate cancer (PCa) and 95 (22.2%) had clinical significant prostate cancer (Gleason Score≥3+4, csPCa). The mean age was 66.46. In our univariate logistic analysis, bpMRI significantly predicts the presence of PCa (Wilcoxon Rank Order test, p<0.001; AUC=0.808) and csPCa (Wilcoxon Rank Order test, p<0.001; AUC=0.822). The negative predictive value for bpMRI (PI-RADS 1 or 2) is 96.65% for the prediction of csPCa and for PCa 88.27%. The negative predictive value of PI-RADS 3 performed similarly in bpMRI (85%) and mpMRI (87.33%) for csPCa.</p>
For patients with elevated tPSA of 4-10 ng/mL, bpMRI can identify 96.65% of csPCa and 88.27% of PCa. In bpMRI PI-RADS 3 patients, bpMRI had a similar diagnostic efficacy with mpMRI. Without the possible adverse effects of contrast agents, bpMRI is a safer and economic alternative for the aforementioned patient group. Moreover, in patients with low risk of csPCa, bpMRI without biopsy can be a possible option to avoid unnecessary invasive procedures.