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


Prostate cancer (PCa) is the most common malignancy in elderly males in the western world. New imaging modalities have provided useful information in the management of patients with PCa. For example: the multiparametric magnetic resonance imaging (mpMRI) of the prostate and subsequent TRUS-targeted biopsies of possible suspicious gland sites. They can be very helpful in special cases to achieve the optimal therapy-option.

Nowadays the role of endorectal magnetic resonance imaging (e-MRI) in the detection, localization and staging of PCa has become a gaining increasing importance as a diagnostic tool in every day urologic practice. (1, 2)

Most of the patients are detected with PCa at an early stage. The number of the relatively late stage diagnosed PCa with a negative digital rectal examination (DRE) is increasing. These tumors seem to be detected in the aspect of the prostate anterior to the urethra (3). The diagnosis of anterior prostate cancer (APC) is a real challenge due to its anatomical position. Patients with an APC often get multiple sets of biopsies until diagnosis is made. The aim of the recent study is to examine if e-MRI of the prostate could enhance the detection of APC.

A closed 1.0-T system (MAGNETOM Harmony; Siemens Medical Solutions, Erlangen, Germany) was combined with an endorectal body phased-array coil (Comp. MEDRAD, Pittsburg, PA, USA). Contrast-enhanced e-MRI (e-dcMRI) and diffusion weighted imaging (DWI) were used. A highly experienced radiologist (defined by: >800 interpreted e-MRI images) analyzed the sequences. 

An APC was diagnosed if the lesion was anterior to the urethra, discrete and homogenously low in signal on T2 images. In e-dcMRI, T1 sequences were  defined as an early enhancement anterior to the urethra. In DWI T2 sequences, restricted diffusion of areas anterior to the urethra was considered as APC. TRUS prostate biopsies were performed with a Siemens Allegra ultrasound machine with a 6.5 MHz sector probe in both studies. After the images were processed, a special 18-core TRUS-guided prostate biopsy with an additional 3-core TRUS-targeted biopsy anterior to the urethra was performed according to the e-MRI findings. 

After the clinic-pathological analyzation and evaluation of the patients´ data, came out, that 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.

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Written by: 
Sandor Poth MD, Department of Urology, Malteser Kliniken Rhein Ruhr, Krefeld, Germany
Vahudin Zugor PD MD, Department of Urology, University Hospital of Cologne, Cologne, Germany

References:

1.Zugor V, Poth S, Kühn R, Bernat MM, Porres D and Labanaris AP: Is an Extended Prostate Biopsy Scheme Associated with an Improvement in the Accuracy Between the Biopsy Gleason Score and Radical Prostatectomy Pathology? A Multivariate Analysis. Anticancer Res. 2016; 36: 4285-8

2.Bott SR, Young MP, Kellett MJ and Parkinson MC: Anterior prostate cancer: is it more difficult to diagnose? BJU Int 2002; 89: 886–9

3.Koppie TM, Bianco FJ Jr, Kuroiwa K, Reuter VE, Guillonneau B, Eastham JA and Scardino PT: The clinical features of anterior prostate cancers. BJU Int 2006; 98: 1167– 71