Endorectal coil magnetic resonance imaging identifies locally advanced prostate cancer in select patients with clinically localized disease.

OBJECTIVES Endorectal coil magnetic resonance imaging (erMRI) has been reported to improve the prediction of pathologic Stage T3 disease in patients with clinical Stage T1,2 disease, prostate-specific antigen (PSA) of 10 to 20 ng/mL, biopsy Gleason score of 7 or less, and at least 50% of the biopsy specimens positive from a sextant sampling. This study examines the performance characteristics of the erMRI to predict established extracapsular extension (ECE), seminal vesicle invasion (SVI), and PSA failure-free survival (bNED) in this subgroup. METHODS The sensitivity, specificity, positive and negative predictive value, and accuracy of the erMRI to predict established ECE and SVI were calculated in the proposed subgroup. PSA failure-free survival stratified by the erMRI-defined stage was estimated by using the method of Kaplan and Meier. RESULTS The sensitivity, specificity, positive and negative predictive value, and accuracy to predict established ECE and SVI in clinical Stage T1,2 patients was 65%, 100%, 100%, 79%, and 84%, respectively. No patient would have been excluded from surgery on the basis of a false-positive study. Moreover, the percent of patients with pathologic organ-confined disease would have increased from 32% to 61%, and the 3-year bNED rate would have increased from 12% to 45% (P = 0.07) if only patients with erMRI Stage T2 disease were selected for surgery. CONCLUSIONS The erMRI may significantly improve the identification of established ECE and SVI in select patients with prostate cancer preoperatively. Further study of the erMRI in these select patients is warranted and ongoing.