[Repeat biopsy of the suspicious prostate cancer: especially the usefulness of MRI]

Among patients with negative initial biopsies of the prostate, 51 patients underwent total 59 repeat biopsies at the Department of Urology of Ikeda Municipal Hospital between January 1998 and April 2004. Overall 26 patients (44.1%) were confirmed to have cancer, 22 patients by second repeat biopsy (22/51), four patients by third biopsy (4/7) and none by fourth biopsy (0/1). Clinical parameters (age, PSA, PSA density, PSA velocity) were analyzed for the possibility to predict the pathological outcome. Significant differences between the positive biopsy group and the negative biopsy group were obtained in age, PSA level and prostatic volume. Of the diagnostic evaluations including palpation and imaging studies (DRE, TRUS, MRI), the most powerful predictor for prostate cancer seemed to be the MRI findings, especially in the cases of short-interval repeat biopsy. Biopsies directed at the positive lesion on MRI in addition to systematic prostate biopsies should be useful.