MP13-04 DO ALL CASES OF MAGNETIC RESONANCE IMAGING NEGATIVE HAVE GOOD PROGNOSIS?

Abstract

INTRODUCTION AND OBJECTIVE: Multiparametric magnetic resonance imaging (mpMRI) has been increasingly used these days and has a role in detecting clinically significant prostate cancer in men with elevated serum prostate-specific antigen levels. However, it is not clear whether mpMRI could reduce unnecessary prostate biopsies when no prostate cancer was detected on mpMRI. The purpose of this study is to assess the accuracy of preoperative mpMRI. METHODS: We retrospectively reviewed the clinicopathological data of 1240 consecutive patients who underwent radical prostatectomy between 2005 and 2018. Multiple variables were evaluated as predictors for the biochemical recurrence after radical prostatectomy. Patients receiving adjuvant therapy were excluded. The preoperative clinical variables and postoperative pathological variables were assessed with multivariate logistic regression. Kaplan-Meier analysis and competing risks regression were used to test cumulative incidence and risk of biochemical recurrence after prostatectomy. RESULTS: The median follow-up was 54 months and the median age was 66 years. In 276 cases, no prostate cancer was detected on preoperative mpMRI (cT1c). In 522 cases, a prostate cancer was detected in less than one-half of one lobe on mpMRI (cT2a). Univariate analysis revealed that serum PSA level (p=0.016), prostate volume (p=0.002), PSA density (p=0.027), percentage of positive/total cores (p<0.001) and Gleason score (p=0.001) were associated with MRI positivity. Multivariate Cox regression analysis showed that percentage of positive/total cores (hazard ratio: 1.602, p=0.011) and Gleason score (hazard ratio: 1.571, p=0.008) were independent indicators of MRI positivity.Of the cT1c stage cases, we compared Gleason score of prostate biopsy and that of prostatectomy. 45% of postoperative results were worse than those of biopsy. 8 patients (3.9%) of low Gleason score (≦3+4) of biopsy resulted in high Gleason score (≧8) after prostatectomy. However, 6 patients (5.1%) of 117 cT1c patients underwent imaging with 1.5 Tesla-MRI, and 2 patients (1.3%) of 159 cT1c patients underwent imaging with 3 Tesla-MRI. CONCLUSIONS: 3 Tesla-MRI is useful for detecting significant prostate cancer before prostate biopsy, so mpMRI could reduce unnecessary prostate biopsies when no prostate cancer was detected on mpMRI. Source of Funding: none