Transrectal US in evaluation of patients after radical prostatectomy. Part I. Normal postoperative anatomy

Prostate cancer post-treatment follow-up and recurrence evaluation

Recurrent prostate cancer following primary treatment is common, and the population of men with biochemical recurrence is complex. Conventional management of recurrent prostate cancer involves nontargeted and/or systemic therapies, without defining an individual patient's specific disease. However, recent advances in imaging enable a shift in the management of recurrent prostate cancer to targeted, patient-specific approaches. Specifically, MRI can detect and define local prostate cancer recurrence early in the course of disease, and prostate-specific PET imaging greatly improves nodal staging and can detect previously unknown distant metastases. The significant advances in the imaging of both local and distant tumor recurrences allows for specific selection of treatment options tailored to patients and their disease with less associated morbidity.

Value of bimodal (18)F-choline-PET/MRI and trimodal (18)F-choline-PET/MRI/TRUS for the assessment of prostate cancer recurrence after radiation therapy and radical prostatectomy

Between 27% and 53% of all patients who undergo radical prostatectomy (RP) or radiation therapy (RT) as the first-line treatment of prostate cancer (PCa) develop a biochemical recurrence. Imaging plays a pivotal role in restaging by helping to distinguish between local relapse and metastatic disease (i.e., lymph-node and skeletal metastases). At present, the most promising tools for assessing PCa patients with biochemical recurrence are multiparametric magnetic resonance imaging (mpMRI) and positron emission tomography (PET)/computed tomography (CT) with radio-labeled choline derivatives. The main advantage of mpMRI is its high diagnostic accuracy in detecting local recurrence, while choline-PET/CT is able to identify lymph-node metastases when they are not suspicious on morphological imaging. The most recent advances in the field of fusion imaging have shown that multimodal co-registration, synchronized navigation, and combined interpretation are more valuable than the individual; separate assessment offered by different diagnostic techniques. The objective of the present essay was to describe the value of bimodal choline-PET/mpMRI fusion imaging and trimodal choline-PET/mpMRI/transrectal ultrasound (TRUS) in the assessment of PCa recurrence after RP and RT. Bimodal choline-PET/mpMRI fusion imaging allows morphological, functional, and metabolic information to be combined, thereby overcoming the limitations of each separate imaging modality. In addition, trimodal real-time choline-PET/mpMRI/TRUS fusion imaging may be useful for the planning and real-time guidance of biopsy procedures in order to obtain histological confirmation of the local recurrence.

Detection of local recurrent prostate cancer after radical prostatectomy in terms of salvage radiotherapy using dynamic contrast enhanced-MRI without endorectal coil

Purpose

To evaluate the value of dynamic contrast enhanced Magnetic Resonance Imaging (DCE-MRI) without endorectal coil (EC) in the detection of local recurrent prostate cancer (PC) after radical prostatectomy (RP).

Material and methods

Thirty-three patients with recurrent PC underwent DCE-MRI without EC before salvage radiotherapy (RT). At median 15 (mean 16±4.9, range 12–27) months after completion of RT all patients showed complete biochemical response. Additional follow up post RT DCE-MRI scans were available. Prostate specific antigen (PSA) levels at the time of imaging were correlated to the imaging findings.

Results

In 22/33 patients (67%) early contrast enhancing nodules were detected in the post-prostatectomy fossa on pre-RT DCE-MRI images. The average pre-RT PSA level of the 22 patients with positive pre-RT DCE-MRI findings was significantly higher (mean, 0.74±0.64 ng/mL) compared to the pre-RT PSA level of the 11 patients with negative pre-RT DCE-MRI (mean, 0.24±0.13 ng/mL) (p<0.001). All post-RT DCE-MRI images showed complete resolution of initial suspicious lesions. A pre-RT PSA cut-off value of ≥0.54 ng/ml readily predicted a positive DCE-MRI finding.

Conclusions

This is the first study that shows that DCE-MRI without EC can detect local recurrent PC with an estimated accuracy of 83% at low PSA levels. All false negative DCE-MRI scans were detected using a PSA cut-off of ≥0.54 ng/mL.

Imaging techniques for local recurrence of prostate cancer: for whom, why and how?

Since there are salvage solutions, it is important to detect local recurrence of prostate cancer as early as possible. The first sign is "biochemical failure" in that the prostate specific antigen (PSA) concentration rises again. The definition of biochemical failure varies depending on the initial treatment: PSA greater than 0.2ng/mL after prostatectomy, nadir+2ng/mL after radiotherapy. There is no standardised definition of biochemical failure after cryotherapy, focused ultrasound, or brachytherapy. Magnetic resonance imaging (MRI) (particularly dynamic MRI) can detect local recurrence with good sensitivity. The role of spectroscopy is still under discussion. For the moment, ultrasound techniques are less effective than MRI.

Role of imaging and biopsy to assess local recurrence after definitive treatment for prostate carcinoma (surgery, radiotherapy, cryotherapy, HIFU)

PURPOSE

Defining the site of recurrent disease early after definitive treatment for a localized prostate cancer is a critical issue as it may greatly influence the subsequent therapeutic strategy or patient management.

METHODS

A systematic review of the literature was performed by searching Medline from January 1995 up to January 2011. Electronic searches were limited to the English language, and the keywords prostate cancer, radiotherapy [RT], high intensity focused ultrasound [HIFU], cryotherapy [CRIO], transrectal ultrasound [TRUS], magnetic resonance [MRI], PET/TC, and prostate biopsy were used.

RESULTS

Despite the fact that diagnosis of a local recurrence is based on PSA values and kinetics, imaging by means of different techniques may be a prerequisite for effective disease management. Unfortunately, prostate cancer local recurrences are very difficult to detect by TRUS and conventional imaging that have shown limited accuracy at least at early stages. On the contrary, functional and molecular imaging such as dynamic contrast-enhanced MRI (DCE-MRI), and diffusion-weighted imaging (DWI), offers the possibility of imaging molecular or cellular processes of individual tumors. Recently, PET/CT, using 11C-choline, 18F-fluorocholine or 11C-acetate has been successfully proposed in detecting local recurrences as well as distant metastases. Nevertheless, in controversial cases, it is necessary to perform a biopsy of the prostatic fossa or a biopsy of the prostate to assess the presence of a local recurrence under guidance of MRI or TRUS findings.

CONCLUSION

It is likely that imaging will be extensively used in the future to detect and localize prostate cancer local recurrences before salvage treatment.

Role of MRI in follow-up after focal therapy for prostate carcinoma

OBJECTIVE

In patients with clinically suspected local recurrence of prostate cancer, a lobulated hyperintense mass in the radical prostatectomy fossa can be readily visualized with T2-weighted MRI, but this imaging technique is less successful after treatments such as radiation therapy, high-intensity focused ultrasound, and cryosurgery. We describe the additional value of functional techniques in the assessment of local recurrence.

CONCLUSION

The use of functional MRI techniques such as MR spectroscopy, diffusion-weighted imaging, and dynamic contrast-enhanced MRI has shown promise in increasing overall imaging performance in the detection of local recurrence.

Diagnostic efficacy of transrectal ultrasound-guided biopsy of the prostatic fossa in patients with rising PSA following radical prostatectomy

To evaluate the diagnostic efficacy of transrectal ultrasound (TRUS)-guided biopsy of the prostatic fossa in men with biochemical relapse following radical retropubic prostatectomy (RP). Thirty patients, with detectable prostate specific antigen (PSA) and negative imaging for metastases after RP, were evaluated for local recurrence. All patients underwent TRUS-guided biopsies of the prostatic fossa, with at least six cores obtained. PSA and digital rectal examination (DRE) were correlated with biopsy results. Twelve patients (40%) were found with local recurrence. Sensitivities of TRUS and DRE were 75 and 50%, while specificities were 83 and 100%, respectively. Local recurrence was detected in 25% of the patients with PSA <or= 1 ng/ml, and higher PSA levels were correlated with an increased positive biopsy rate. All patients with positive DRE had positive biopsy and positive TRUS as well. When both TRUS and DRE were positive it was more likely for the patient to have positive biopsy than when both TRUS and DRE were negative. TRUS-guided biopsy is an efficient tool in detecting local recurrence after RP and should be offered to all patients with biochemical relapse and absence of metastatic disease irrespective of the level of PSA.

The potential value of power Doppler ultrasound imaging compared with grey-scale ultrasound findings in the diagnosis of local recurrence after radical prostatectomy

AIM

To determine the value of power Doppler ultrasound (PDUS) imaging during transrectal ultrasonography (TRUS) in detecting local recurrence after radical retropubic prostatectomy (RRP).

MATERIALS AND METHODS

Eighteen patients were evaluated in whom local recurrence of prostate cancer was suspected on the basis of elevated serum prostate-specific antigen (PSA) levels (above 0.4 ng/ml) after RRP with no evidence of metastatic disease. Grey-scale TRUS and PDUS-guided biopsies of the vesicourethral anastomosis (VUA) and perianastomotic soft tissues were obtained after TRUS examinations of the prostatic fossa. The ability to detect locally recurrent prostate cancer using grey-scale TRUS alone was compared with TRUS combined with PDUS.

RESULTS

Fifteen of the 18 patients (83%) had positive biopsies for local recurrent tumour at histological examination. TRUS alone detected grey-scale abnormalities in 15 of 18 patients (83%), of whom 14 (77%) had positive TRUS-guided biopsies. PDUS during TRUS showed hypervascularity in 14 of 18 patients (77%). Biopsies of these hypervascular regions were positive in all patients (100%). The sensitivity and specificity of TRUS alone in detecting recurrent tumour were 93 and 67%, respectively, with a positive predictive value (PPV) of 93% and a negative predictive value (NPV) of 67%. TRUS combined with PDUS had a sensitivity and specificity of 93 and 100%, respectively, with a PPV and a NPV of 100 and 75%, respectively.

Les thérapeutiques et la surveillance dans le cancer de la prostate et leurs implications sur l’imagerie

Multiple treatments are proposed to cure prostate carcinoma. Radical prostatectomy is the classical option for localized tumor. However radiotherapy can be proposed in such circumstances with the argument of a less invasive procedure with similar results. High Intensity Focalised Ultrasound (HIFU) is a new technique available for similar staging of the carcinoma with good results. Follow up is based on biological evaluation of PSA. Imaging studies are required only in cases of abnormal level. Endorectal Ultrasonography with biopsies is useful after radical surgery. Indications for MRI study is mainly to differentiate a localized from a general recurrence.

Postradical prostatectomy TRUS-guided anastomotic biopsy. Where do we stand today?

The issue of performing tissue sampling from the vesicourethral anastomotic area postradical prostatectomy (transrectal ultrasound-guided biopsy) after radical surgical treatment of local disease has failed, still remains controversial. We review a selection of articles that evaluate this procedure as well as newer diagnostic modalities and we discuss how this technique may have a position in our treatment dilemmas in cases with biochemical failure of undetermined origin.

Multiple vesico-urethral biopsies following radical prostatectomy: the predictive roles of TRUS, DRE, PSA and the pathological stage

INTRODUCTION

The aim of this study is to verify the predictive role of transrectal ultrasound (TRUS) of prostatic fossa, digital rectal examination (DRE), prostate specific antigen (PSA) and pathological stage after radical prostectomy in the detection of a prostate tumor recurrence at the level of the vesico-urethral anastomosis by means of multiple TRUS biopsies (6-8 cores).

MATERIAL AND METHODS

From October 1997, following a radical prostatectomy, 119 consecutive patients (median age: 67.9 years) with a PSA>or=0.2 ng/ml (median PSA: 0.9 ng/ml) underwent DRE and TRUS examinations with a 5.0-7.5 MHz variable frequency end-fire probe (Hitachi Medical System) and an EUB-525 machine. All patients received six TRUS-guided biopsies of the vesico-urethral anastomosis, and 1-2 additional biopsies directed to hypo-echoic or suspicious areas, if detected by TRUS.

RESULTS

Biopsies revealed recurrent carcinoma in 50% of patients (60/119). TRUS proved more sensitive than DRE (75% vs. 50%; p=0.01) and, conversely, DRE proved more specific than a TRUS (85% vs. 66%; p=0.03). Cancer was detected in 45% of the 34 patients with a PSA<or=0.5 ng/ml. In the group of patients with a PSA>or=2.0 ng/ml (24 patients), TRUS was able to detect every biopsy-proven local recurrence lesion (sensitivity: 100%). Conversely, all patients with a PSA>or=2.0 ng/ml and a negative TRUS had a negative biopsy (negative predictive value: 100%). In a multi-variable logistical analysis, the most predictive parameters determining a positive biopsy rate among those values studied (PSA, DRE, TRUS, positive surgical margins, pathological stage and time to PSA elevation) were TRUS and DRE findings (p=0.003, with an odds ratio of 4.6 and p=0.02, with an odds ratio of 4.1, respectively).

CONCLUSION

TRUS and TRUS biopsies utilizing 6-8 cores are efficient tools in the detection of local recurrence after a radical prostatectomy, even with a PSA<or=0.5 ng/ml. A combination of TRUS and DRE findings seems to predict biopsy results best. In case of a PSA>or=2.0 ng/ml and a negative TRUS, a biopsy of the vesico-urethral anastomosis could be avoided since the negative predictive value is 100%. Cancer recurrence detection seems to be predicted by TRUS and DRE findings, but not by PSA levels, pathological stage, status of the surgical margins or time to PSA elevation.

Pseudomass of the bladder neck after prostatectomy: report of two cases

The authors reviewed ultrasonographic (US) images, cystoscopic findings, and biopsy results at the vesicourethral anastomosis in two patients suspected of having local recurrence after radical prostatectomy. A focal, masslike bulge was identified with US at the posterior aspect of the bladder neck, just above the anastomosis. This bulge mimicked the appearance of local recurrence of cancer; however, diagnostic studies, biopsy results, and clinical follow-up failed to demonstrate recurrent cancer. A review of the surgical technique led the authors to conclude that a pseudomass at the vesicourethral anastomosis may result from focal infolding of normal bladder mucosa.

Local recurrence after radical prostatectomy: correlation of US features with prostatic fossa biopsy findings

PURPOSE

To evaluate the diagnostic accuracy of transrectal ultrasonography (US) in the detection of local recurrence following radical prostatectomy.

MATERIALS AND METHODS

Ninety-nine patients with biochemical recurrence after radical prostatectomy were evaluated at transrectal US and prostatic fossa biopsy. Location of suspected recurrence at transrectal US and clinical features, such as prostate-specific antigen levels and digital rectal examination findings, were correlated with biopsy results.

RESULTS

Forty-one (41%) of 99 cases of local recurrence were detected. The percentage of sites of lesions identified at transrectal US and corresponding positive biopsy rates were as follows: the urethrovesical anastomotic area, 56% and 61%; bladder neck, 26% and 54%; retrovesical space, 4% and 100%; and more than one site, 14% and 71%. By comparing transrectal US and digital rectal examination, the sensitivities were 76% and 44% (P =.007), while specificities were 67% and 91% (P =.004), respectively. An increased positive biopsy rate with increasing prostate-specific antigen levels was noted (P =.04).

CONCLUSION

Transrectal US is more sensitive but less specific than digital rectal examination in the detection of local recurrence. Biopsy findings in more than half of the suspected lesions at the urethrovesical anastomotic area and bladder neck were positive. Lesions in the retrovesical space, although less frequently encountered, had a high likelihood of representing cancer recurrence.

[Transrectal ultrasonography in the assessment of patients after radical prostatectomy. Normal and pathologic ultrasonography anatomy of vesico-urethral anastomosis]

OBJECTIVE

To determine the ultrasound characteristics of the vesico-urethral anastomotic complex in patients with radical prostatectomy to separate normal prostate fossae from those affected by local recurrence or residual tumour.

MATERIAL AND METHODS

Between January 1998 and June 1999 15 ultrasound guided transrectal biopsies of vesico-urethral anastomosis or prostate fossae were performed in patients with radical prostatectomy. The selection criteria to perform puncture in these patients were a negative extension study (abdominal-pelvic CT and bone scan), PSA higher than 0.4 ng/mL and/or suspicious DRE. The study was completed with 10 transrectal ultrasound (TRU) after radical prostatectomy in patients with normal PSA and DRE. TRU parameters in patients with tumour-positive biopsies were compare to those from patients with negative biopsies and those obtained from TRU in patients with both normal PSA and normal DRE.

RESULTS

The ultrasound parameters that best described prostate fossa abnormalities were the presence of hypoechoic masses or nodes and the integrity or not of the retro-anastomotic fat layer. When a hypoechoic mass or node was found at the anastomosis level, 80% biopsies were positive for tumour local recurrence. The percentage increases when changes are seen at the retro-anastomotic fat layer.

CONCLUSIONS

In spite of a good correlation between ultrasound abnormalities and positive biopsies, ultrasound findings from the vesico-urethral anastomosis in patients with radical prostatectomy are not well defined. Nodes or ultrasound irregularities can exist in normal prostate fossae as well as normal anastomosis ultrasound in the presence of tumoral relapses. We believe TRU of vesico-urethral anastomosis to be the best method available to evaluate local recurrence or tumoral persistence after radical prostatectomy.

Assessment of endpoints for clinical trials for localized prostate cancer

OBJECTIVES

The AUA Practice Guidelines Panel convened to address the issue of appropriate endpoints for assessment of treatment modalities for localized carcinoma of the prostate.

METHODS

A review of the literature and the design of existing clinical trials produced a consensus, which was presented to and critiqued by the members of the general conference.

RESULTS

The pitfalls associated with identification of local failure endpoints were discussed, and the more accurate endpoints of freedom from metastatic progression and overall survival were recognized. The strict definition that must be fulfilled for intermediate endpoints to become surrogates for metastasis free and/or survival endpoints was stressed. For more efficient and rapid conduct of future clinical trials, the urgent need to validate such surrogate endpoints by evaluation in randomized control trials is obvious. PSA, while an indicator of disease activity and a critical marker for estimating disease progression or regression in response to therapy, is not a surrogate for metastasis free or overall survival.

CONCLUSION

Until surrogate endpoints are validated, the committee has evaluated the endpoints in current use, reviewed their limitations, and stressed the importance of quality-of-life assessment together with the traditional endpoint assessment.

Transrectal ultrasound of the prostate bed after collagen injection

OBJECTIVE

Transurethral injection of collagen (TCI) may be used to treat urinary incontinence following radical prostatectomy for prostate cancer. The transrectal ultrasound (TRUS) findings after TCI are described in this report.

MATERIALS AND METHODS

TRUS exams of four postprostatectomy patients who had undergone TCI were reviewed. Findings were correlated with pathologic specimens obtained at TRUS-guided core biopsy. These histologic specimens were compared with others from postprostatectomy patients who had not undergone TCI.

RESULTS

Well defined bladder apex masses of uniform echogenicity, hypoechoic to adjacent fat and muscle, were identified sonographically in all TCI patients. Masses from which positive biopsies were obtained were similar in appearance to those with no malignancy. Hypocellular fibrous tissue and foci of acellular loose connective tissue were identified in the biopsies of those patients who had undergone TCI. No acellular areas were identified in specimens from patients who had not had TCI.

CONCLUSION

Sequelae of TCI should be included in the differential diagnosis of perianastomotic masses in postprostatectomy patients. However, the need for biopsy is not obviated as residual or recurrent prostate carcinoma may coexist.

Computed tomography appearance of the prostatic fossa following radical prostatectomy

RATIONALE AND OBJECTIVES

We assessed the value of postsurgical computed tomography (CT) in detecting locally recurrent prostatic carcinoma and determined the most effective CT findings.

METHODS

We studied 13 patients with recurrent disease (prostate specific antigen [PSA] > 0.4 ng/ml) and 11 patients with no evidence of recurrence (PSA < 0.3 ng/ml). Pelvic CT scans were independently interpreted by four readers who were unaware of patient status. Readers measured tissue volume in the prostatic fossa and evaluated each scan for the presence of six potentially discriminating criteria. We determined sensitivity and specificity and developed mean and pooled receiver operating characteristic (ROC) curves for each criterion and for overall rating.

RESULTS

The respective mean ROC curves, sensitivity, and specificity for each criterion were as follows: irregular tissue margins = .50, .67, and .32; inhomogeneous tissue density = .35, .76, and .11; asymmetric residual seminal vesicles = .68, .86, and .16; fat infiltration around seminal vesicles = .67, .69, and .43; infiltration of perirectal fat = .60, .71, and .40; and margins of the levator ani = .50, .78, and .09. The overall rating of whether a scan was normal or reflected recurrent cancer was .56, .75, and .32. Mean tissue volume in the prostatic fossa was 15.01 cm3 for the positive cases and 11.06 cm3 for the negative cases (p < .05), but because of a large overlap, this difference was not practically significant.

CONCLUSION

CT scanning is not an effective technique for detecting recurrent prostate malignancy. Normally, there is a moderate amount of soft tissue in the prostatic fossa postoperatively that should not be confused for malignancy.

Use of transrectal ultrasound in follow-up of postradical prostatectomy

The appearance of the prostatic fossa on transrectal ultrasound following radical retropubic prostatectomy (RRP) is described. Transrectal ultrasonography was performed on 25 patients with normal bone scans and pelvic computed tomography from three to ninety months after RRP using a biplane high frequency probe. The area of the vesicourethral anastomosis (VUA) was identified, its contour characterized, surrounding tissues described, and changes induced by pelvic muscle contraction recorded. In 16 of these patients who had abnormal postoperative serum prostate-specific antigen levels, digital and ultrasound-guided transrectal needle biopsies for local recurrence were done and compared. The VUA was identifiable in all patients as either a smoothly tapered narrowing usually correlating with the presence of continence or distorted or blunted profile which often correlated with absence of urinary continence. The VUA was surrounded almost invariably by hypoechoic soft tissue which was pathologically nonspecific on biopsy. An extrinsic impression on the anterior bladder wall was noted in 80 percent. There was no clear distinguishing ultrasound feature for biopsy-proved local recurrence. The apparent length of the apposed walls of the urethra suggests a urethral high pressure zone (UHPZ). This lengthened significantly with voluntary contraction of the pelvic floor muscles.