A COMPARISON OF ENDORECTAL MAGNETIC-RESONANCE-IMAGING AND TRANSRECTALULTRASONOGRAPHY IN THE LOCAL STAGING OF PROSTATE-CANCER WITH HISTOPATHOLOGICAL CORRELATION

Objective To assess the staging accuracy of endorectal magnetic resona nce imaging (MRI), using a mid-field system, in patients with clinical ly localized prostate cancer and to compare the results with transrect al ultrasonography (TRUS). Patients and methods Twenty patients with c linically localized prostate cancer were prospectively staged with TRU S and endorectal MRI using a 0.5 T magnet, All patients subsequently u nderwent radical prostatectomy and the results of pre-operative stagin g were compared with the histological findings. Results The sensitivit y and specificity for diagnosing capsular penetration were 38% and 100 %, respectively, for endorectal MRI, and 23% and 86% for TRUS. The sen sitivity and specificity for diagnosing seminal vesicle invasion were 100% and 94%, respectively, for endorectal MRI, and 33% and 100% for T RUS. The overall staging accuracy for endorectal MRI was 75% compared with 50% for TRUS.Conclusion Compared with TRUS, endorectal MRI with a 0.5 T magnet provided greater sensitivity and specificity for capsula r penetration and increased sensitivity for seminal vesicle invasion.