Use of endorectal MR imaging to predict prostate carcinoma recurrence after radical prostatectomy

PURPOSE: To determine the ability of endorectal magnetic resonance (MR) imaging to help predict postprostatectomy disease recurrence and, thereby, patient outcome. MATERIALS AND METHODS: The authors evaluated 116 patients referred for prostate MR imaging during 1991 and 1992 who subsequently underwent radical prostatectomy and for whom follow-up data through 1996 could be obtained. The MR reports, clinic charts, and pathology reports were reviewed. Disease recurrence was established by means of detectable levels of serum prostate-specific antigen (PSA) after surgery. RESULTS: Thirty-four patients (29%) had postoperative disease recurrence. Patients with recurrence had higher preoperative PSA values (P < .0001). These patients also more frequently had positive surgical margins (P = .0005), transcapsular tumor spread (P < .0001), seminal vesicle involvement (P = .0012), and tumors of advanced stage (P <. 0001) and high grade (P = .0058). Of 13 patients whose MR examinations showed definite extracapsular disease, eight (62%) had disease recurrence. The recurrence rate when MR imaging indicated limited disease (24%) was similar to that when MR imaging showed possible microscopic extension (27%). An MR finding of definite extracapsular disease was 24% sensitive and 94% specific for the prediction of disease recurrence. CONCLUSION: MR imaging findings of definite extracapsular spread of disease helped predict prostate tumor recurrence with high specificity, although with low sensitivity.