The role of magnetic resonance imaging in targeting prostate cancer in patients with previous negative biopsies and elevated prostate-specific antigen levels

In the past 20 years, magnetic resonance imaging (MRI) has developed rapidly, along with the management of localized prostate cancer. We summarize current data on the efficacy of MRI for targeting cancer, compared with biopsies, in patients with previous negative prostate biopsies and persistently elevated prostate-specific antigen (PSA) levels. The key clinical question is how many men benefit by having had prostate cancer detected purely because of the MRI-targeted, as opposed to standard scheme, biopsies. We reviewed all available databases for prospective studies in patients having MRI and prostate biopsy with previous negative biopsies and persistently elevated PSA levels. Six studies fulfilled the selection criteria, with 215 patients in all; in these studies, the cancer-detection rate at repeat biopsy was 21-40%. For MRI or combined MRI/MR spectroscopy, the overall sensitivity for predicting positive biopsies was 57-100%, the specificity 44-96% and the accuracy 67-85%. In five studies, specific MRI-targeted biopsies and standard cores were taken, with a significant proportion (34/63, 54%) having cancer detected purely because of the MRI-targeted cores. The value of endorectal MRI and MR spectroscopy in patients with elevated PSA levels and previous negative biopsies to target peripheral zone tumours appears to be significant. Although more data obtained with current technologies are needed, published results to data are encouraging. A comparison study and cost-benefit analysis of MRI-targeted vs saturation biopsy in this group of patients would also be ideal, to delineate any advantages.