Prostate carcinoma (PCa) is one of the most common cancers in males.
Clinical screening of PCa,
based on combined digital rectal examination (DRE) and prostatic serum antigen (PSA),
has increased the detection of early-stage PCa that is curable with surgical resection [1].
After a successful radical prostatectomy (RP),
PSA becomes undetectable (<1.0 ng/mL) within one month [2].
Recurrent disease should be considered in presence of any increase of PSA after RP and should be suspected particularly when a trend of rising PSA in three consecutive measurements is present [1,2].
The risk of recurrence after RP is correlated with preoperative PSA level,
pathologic stage,
Gleason score and surgical margin status.
An increase of PSA level,
however,
can detect the biochemical recurrence of PCa without providing precise information about the location of relapse,
which can be local (i.e.
at the side of the RP bed) or systemic (i.e.
skeletal or other organs).
These two conditions should be clearly differentiated,
because they can benefit of different therapies: in the first case,
in fact,
a local salvage therapy can be attempted (i.e.
surgery or radiotherapy); in the second case,
a curative systemic therapy can be used (i.e.
hormonotherapy) [1,2].
Trans-rectal ultrasound (TRUS) is a simple and minimally invasive tool for evaluating vesico-urethral anastomosis and can be used to guide the biopsy when a local recurrence is suspected.
TRUS allows good visualization of the vesico-urethral anastomosis after RP,
which is usually surrounded by moderately hyperechoic and homogeneous tissue; in this context local recurrences usually appear as hypoechoic masses [3].
Unfortunately,
TRUS can not easily distinguish between fibrous and tumor tissue,
even if color/power Doppler imaging or ultrasound contrast agents are used.
Due to its high contrast resolution,
Magnetic resonance imaging with endorectal coil (endorectal-MRI),
is able to provide an excellent evaluation of the vesico-urethral anastomosis after RP.
The potential role of fast dynamic contrast-enhanced MRI (DCE-MRI) in the detection of hypervascular prostate cancer recurrences after radical surgery,
has already been demonstrated in some preliminary studies [4,5].
In this context the role of molecular diffusion techniques (DWI) has not been defined yet,
even if some authors have already described the high sensitivity of DWI in detecting recurrent prostate cancer after high-dose-rate brachiterapy [6].
Therefore,
the purpose of our study was to present the value of DCE-MRI combined with DWI in detecting local recurrence of PCa after RP,
by using clinical and histopathologic findings as the reference standard.