A comparison of transrectal ultrasonography and endorectal magnetic resonance imaging in the local staging of prostatic carcinoma

Objective To compare the staging accuracy of transrectal ultrasonography (T RUS) and endorectal magnetic resonance imaging (eMRI) for organ-confined pr ostatic carcinoma. Patients and methods Twenty-five patients with clinically confined prostati c adenocarcinoma were evaluated to be candidates for radical prostatectomy. All underwent TRUS and eMRI before surgery. Imaging findings evaluated pro spectively in each patient were extracapsular extension (ECE), seminal vesi cle invasion (SVI) and the site of involvement. The results of the imaging techniques were compared with the histopathological findings. As two patien ts with metastatic lymph nodes (detected on frozen-section examination duri ng surgery) were spared radical prostatectomy, the final evaluation include d 23 patients. Results Endorectal coil MRI was more sensitive than TRUS for detecting both ECE, SVI and the site of ECE involvement in organ-confuted prostatic carci noma. TRUS was more accurate than eMRI for detecting the site of SVI involv ement, However, the overall staging accuracy rates for both imaging modalit ies were equal. Conclusions Neither TRUS nor eMRI was significantly better than the other f or determining the local extent of prostatic carcinoma, Therefore, TRUS sho uld be the study of choice until MRI technology improves sufficiently in th e preoperative staging of localized prostate cancer.