Endorectal and dynamic contrast-enhanced MRI for detection of local recurrence after radical prostatectomy

OBJECTIVE. The objective of our study was to evaluate the sensitivity and specificity of endorectal MRI combined with dynamic contrast-enhanced MRI to detect local recurrence after radical prostatectomy. MATERIALS and METHODS. A total of 51 patients who had undergone radical prostatectomy for prostatic adenocarcinoma 10 months to 6 years before underwent a combined endorectal coil MRI and dynamic gadolinium- enhanced MRI before endorectal sonographically guided biopsy of the prostatic fossa. The MRI combined with MR dynamic imaging results were correlated with the presence of recurrence defined as a positive biopsy result or reduction in prostate-specific antigen level after radiation therapy. RESULTS. Overall data of 46 ( 25 recurred, 21 nonrecurred) out of 51 evaluated patients were analyzed. All recurrences showed signal enhancement after gadolinium administration and, in particular, 22 of 24 patients ( 91%) showed rapid and early signal enhancement. The overall sensitivity and specificity of MR dynamic imaging was higher compared with MRI alone ( 88%, [ 95% CI] 69 - 98% and 100%, 84 - 100% compared with 48%, 28 - 69% and 52%, 30 - 74%). MRI combined with dynamic imaging allowed better identification of recurrences compared with MRI alone ( McNemar test: chi-square 1 = 16.67; p = < 0.0001). CONCLUSION. MRI combined with dynamic contrast-enhanced MRI showed a higher sensitivity and specificity compared with MRI alone in detecting local recurrences after radical prostatectomy.