Poor standard mp-MRI and routine biopsy fail to precisely predict intraprostatic tumor localization.

PURPOSE: To evaluate the localization accuracy of routinely performed preoperative multiparametric MRI (mp-MRI), not being assessed according to PI-RADS criteria. METHODS: One hundred and six patients underwent radical retropubic prostatectomy (January 2011-June 2012) with preoperative MRI. Intraprostatic tumor localization suggested by mp-MRI was correlated to both biopsy and histopathology results. RESULTS: Sensitivity and specificity were as low as 25-62 and 60-94 %, respectively. Neither higher field force nor the use of an endorectal coil could enhance accuracy. There was no statistically significant concordance in any sextant. The mean number of correctly identified sextants was between 3.11 and 4.00 and, thus, insignificantly above the value of 3 that one would obtain by tossing the coin. For transrectal biopsies, sensitivity and specificity of tumor localization were 52-63 and 46-80 %, respectively. CONCLUSIONS: Neither routinely performed "non-PI-RADS" MRI nor transrectal biopsy can accurately localize prostate cancer. Focal therapy concepts rely on a precise intraprostatic tumor detection and therefore inevitably require PI-RADS assessment by radiologists with genitourinary specialization. Regarding patient discomfort and costs, "non-PI-RADS" MRIs of the prostate are not justified.

Preoperative mp-MRI of the prostate provides little information about staging of prostate carcinoma in daily clinical practice.

PURPOSE: To evaluate the staging accuracy of preoperative multiparametric MRI (mp-MRI), its influence on the technique of radical retropubic prostatectomy (RRP), and its value for daily clinical practice. METHODS: A total of 106 patients underwent RRP (January 2011-June 2012) and had preoperative MRI staging data available for review. Staging results acquired by mp-MRI were correlated to both biopsy and histopathology results. Surgical reports were reviewed for intraoperative aspect of tumor extension, technique of RRP (nerve sparing or extended), and extent of lymphadenectomy. RESULTS: The accuracy of diagnosing extracapsular extension (ECE) was 72.2 %, with an overall sensitivity and specificity of 30.0 and 93.3 %, respectively. The negative predictive value was 72.7 %. The sensitivity and specificity to diagnose positive seminal vesical invasion (SVI) were 63.6 and 92.9 %, respectively. Neither higher field force nor the use of an endorectal coil could enhance the accuracy of mp-MRI. In case of awareness of an existing MRI, there was a significantly higher percentage of nerve protection (left: 93 %; right: 89 % vs. left 75 %; right: 75 %). The higher percentage of nerve sparing surgery did not result in a higher level of positive resection margins. CONCLUSIONS: In routine clinical practice, mp-MRI at non-academic centers has very limited clinical value in predicting ECE and SVI. Our data support the current recommendations against the widespread preoperative use of mp-MRI because it is not adding reliable predictive information on the extent of prostate cancer.