ABSTRACT
PURPOSE: We evaluated the ability of endo-rectal coil MRI (ER-MRI) to predict the local pathological stage of prostate cancer prior to radical prostatectomy and compared the results with those of transrectal ultrasonography (TRUS). MATERIALS AND METHODS: ER-MRI using high field magnets (1.5 Tesla) were performed in 22 patients (mean age 62.8 years, range 51-73) with clinically localized prostate cancer before radical prostatectomy. Of the 22 patients, 17 patients were also assessed by TRUS. The results of the imaging techniques were compared with the post-operative histopathological findings. As one patient with pelvic lymph node metastasis, which was detected on frozen-section examination during surgery, was spared radical prostatectomy, the final evaluation included 21 patients. RESULTS: DSeven of the 21 patients (33%) were found to have extraprostatic extension (EPE), and 5 had seminal vesicle invasion (SVI). The sensitivity and specificity for diagnosing EPE using ER-MRI were 62.5% and 84.6%, respectively, and 16.7% and 100% with TRUS. The sensitivity and specificity for diagnosing SVI were 80.0% and 93.8%, respectively with ER-MRI, and 0% and 92.3% with TRUS. The accuracy of predicting SVI was 90.5% with ER-MRI compared to 70.6% with TRUS. CONCLUSIONS: ER-MRI was significantly better than TRUS for determining the local extent of prostatic cancer and for prediction of SVI in the preoperative staging of clinically localized prostate cancer.