Methods: We assessed the staging accuracy of endorectal magnetic resonance imaging (eMRI) and transrectal ultrasonography (TRUS) for localized prostate cancer. 54 patients with biopsy proven prostate cancer underwent TRUS and eMRI prior to radical retropubic prostatectomy. The MR images were prospectively interpreted by two radiologists. These findings were compared with the histopathological results.
Results: Overall accuracy of eMRI in defining local tumor stage was 93% by radiologist A and 56% by radiologist B. Overall accuracy by TRUS was 63%. Analysis of interobserver agreement showed a poor correlation regarding MRI studies. Endorectal MRI was more sensitive than TRUS for detecting capsular penetration and seminal vesicle involvement. TRUS revealed a relatively high specificity and was superior to eMRI in this regard.
Conclusion: This series shows the current limited value of TRUS and eMRI for planning treatment in patients with clinically localized prostate cancer.