The Value of Endorectal Magnetic Resonance Imaging of the Prostate in Improving the Detection of Anterior Prostate Cancer

The diagnosis of anterior prostate cancer (APC) is troublesome due to its anatomical location. Patients with an APC often require multiple sets of biopsies until diagnosis is made. The objective of this study is to examine if endorectal magnetic resonance imaging (e-MRI) of the prostate could improve the detection of APC. A retrospective review of 412 patients records with a clinical suspicion of prostate cancer (PCa) (prostate-specific antigen (PSA) levels >4 ng/ml or a suspicious finding on digital rectal examination (DRE)) who underwent conventional e-MRI (e-cMRI) and functional e-MRI (e-fMRI) of the prostate and subsequent prostate biopsy from April 2004 to July 2010 was conducted. All patients had a history of at least one prior negative set of prostate biopsy. Sixty-five percent (N=268) of patients' images were considered suspicious for PCa of which 53 (12.8%) cases were considered to be suspicious for APC (defined as the presence of PCa anterior to the urethra). All patients underwent an 18-core transrectal ultrasonography (TRUS)-guided biopsy of the peripheral zone and an additional 3-core TRUS-targeted biopsy anterior to the urethra. The median age and median PSA levels of the patients was 68.9 (range=56-72) years and 12.7 ng/ml (range=6.4-21.3), respectively. DRE was only positive in 6 patients (11.4%). The overall PCa detection rate was 90.5%. APC was detected through the targeted cores in 48 patients (90.5%). Seven patients (13.2%) exhibited a PCa of the peripheral zone as well. e-MRI-positive predictive value was 90.5%. e-MRI of the prostate has a high predictive value in detecting APC. Patients with a constant increase of PSA levels, negative DRE findings and prior negative sets of prostate biopsy are ideal candidates for e-MRI of the prostate and subsequent TRUS-targeted biopsies of possible suspicious anterior gland sites.