Sensitivity and specificity evaluation of endorectal magnetic resonance imaging and transrectal sonography in the staging of prostate cancer

Abstract

OBJECTIVES. Nowadays endorectal probes for Magnetic Resonance Imaging (MRI) have better resolutions, which allows to acquire high-level images of prostate and to improve the MRI sensitivity and specificity to determine the cancer volume and the extraprostatic extension. The objective of the present study is to evaluate the sensitivity and diagnostic accuracy of endorectal MRI for identifying the local extension of prostate carcinoma compared to transrectal sonography (TRUS) of prostate. MATERIALS AND METHODS. The study included 81 patients with clinical suspect of cancer and/or elevated values of serum prostate specific antigen (PSA), who underwent endorectal MRI with 1.5 T endorectal probe before transrectal biopsy. Patients with localized prostate cancer underwent radical surgery. The results of endorectal MRI were compared to those of TRUS and histopathological examination outcomes. RESULTS. 15 of the 81 enrolled patients had extraprostatic localization of cancer, which was assessed through TRUS in 4 cases only (26%), and through MRI in 7 cases (46%). A seminal vesicle involvement was present in 10 patients, detected by MRI in 5 cases and in no cases by TRUS. DISCUSSION AND CONCLUSIONS. Data are similar to the findings collected by several Authors. The endorectal MRI has a better accuracy in staging prostate cancer compared to TRUS. Nevertheless, this procedure has some limits: little availability of equipment in hospitals, physicians' little experience, and higher costs compared to TRUS.