Preoperative Stating of Pelvic Lymph Nodes in Prostate Cancer Patients via Endorectal Magnetic Resonance Imaging

BACKGROUND/AIM: The aim of this study was to evaluate the diagnostic sensitivity, specificity and accuracy of endorectal magnetic resonance imaging (e-MRI), as a preoperative staging modality in the diagnosis of lymph node metastasis (LNM) in patients with prostate cancer (PCa). PATIENTS AND METHODS: Retrospectively, we analyzed data from N=168 patients who underwent radical prostatectomy (RP) between 2004 and 2013 at two tertiary medical centres. Prior to RP all patients underwent an e-MRI. Inclusion criteria were: PSA levels >20 ng/ml or Gleason score >7. Examinations were performed on a closed 1.0-T system combined with an endorectal body phased-array coil, imaging results were correlated with histopathology. RESULTS: 10.7% (N=18 patients) had histologically-proven LNM. e-MRI was true-positive in N=6 (33.3%) and false-negative N=12 patients (66.6%). N=150 (89.3%) patients without LNM e-MRI were true-negative in 96% and false-positive in 4%. Sensitivity was 96%, specificity was 33%, accuracy was 64.5%. CONCLUSION: e-MRI can be considered a useful preoperative staging modality in diagnosis of LNM.