Accuracy of preoperative endo-rectal coil magnetic resonance imaging in detecting clinical under-staging of localized prostate cancer

Predictive Factors of the Risk of Long-Term Hospital Readmission after Primary Prostate Surgery at a Single Tertiary Referral Center: Preliminary Report

OBJECTIVE

To evaluate the predictors of the risk of long-term hospital readmission after radical prostatectomy (RP) in a single tertiary referral center where both open RP (ORP) and robot assisted RP (RARP) are performed.

MATERIALS AND METHODS

The risk of readmission was evaluated by clinical, pathological, and perioperative factors. Skilled and experienced surgeons performed the 2 surgical approaches. Patients were followed for complications and hospital readmission for a period of 6 months. The association of factors with the risk of readmission was assessed by Cox's multivariate proportional hazards.

RESULTS

From December 2013 to 2017, 885 patients underwent RP. RARP was performed in 733 cases and ORP in 152 subjects. Extended pelvic lymph node dissection (ePLND) was performed in 479 patients. Hospital readmission was detected in 46 cases (5.2%). Using a multivariate model, independent factors associated with the risk of hospital readmission were seminal vesicle invasion (hazard ratio [HR] 2.065; 95% CI 1.116-3.283; p = 0.021), ORP (HR 3.506; 95% CI 1.919-6.405; p < 0.0001), and ePLND (HR 5.172; 95% CI 1.778-15.053; p < 0.0001).

CONCLUSIONS

In a large single tertiary referral center, independent predictors of the risk of long-term hospital readmission after RP included ORP, ePLND, and seminal vesicle invasion. When surgery is chosen as a primary treatment of PCA, patients should be informed of the risk of long-term hospital readmission and its related risk factors.

Clinical factors stratifying the risk of tumor upgrading to high-grade disease in low-risk prostate cancer

PURPOSE

To identify clinical factors stratifying the risk of tumor upgrading to increasing patterns of the tumor grading system in low-risk prostate cancer (PCa).

METHODS

We evaluated the records of 438 patients who underwent radical prostatectomy. Associations between clinical factors and tumor upgrading were assessed by the univariate and multivariate multinomial logistic regression model.

RESULTS

Low-risk PCa included 170 cases (38.8%) and tumor upgrading was detected in 111 patients (65.3%): 72 (42.4%) had pathology Gleason pattern (pGP) 3 + 4, 27 (15.9%) pGP 4 + 3, and 12 (7.1%) pGP 4 + 4. Prostate- specific antigen (PSA) and proportion of positive cores (P+) were independent predictors of upgrading to high-risk disease. These factors also stratified the risk of tumor upgrading to the increasing patterns of the tumor grading system. The model allowed the identification of pGP 4 + 4. The main difference between high-risk PCa and other upgraded tumors related to PSA load (odds ratio 2.4) that associated with high volume disease in the specimen.

CONCLUSIONS

Low-risk PCa is a heterogeneous population with significant rates of tumor upgrading. Significant clinical predictors stratifying the risk of tumor upgrading to increasing patterns of the grading system included PSA and P+. These factors allowed the identification of the subset hiding high-grade disease requiring further investigations before delivering active treatments.

Initial risk stratification and staging in prostate cancer with prostatic-specific membrane antigen positron emission tomography/computed tomography: A first-stop-shop

Current imaging for prostate cancer (PCa) had limitations for risk stratification and staging. Magnetic resonance imaging frequently underestimated lymph node metastasis while bone scintigraphy often had diagnostic dilemmas. Prostatic-specific membrane antigen (PSMA) positron emission tomography-computed tomography (PET/CT) has been remarkable in PCa recurrence. Ninety-seven PSMA PET-CT scans were reanalyzed for tumor node metastases staging and risk stratification of lymph node and distant metastasis proportion. Histopathology of 23/97 patients was available as gold standard. Chi-square test was used for proportion comparison. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), overestimation, underestimation, and correct estimation of T and N stages were calculated. Kappa coefficient (κ) was derived for inter-rater agreement. Lymph node or distant metastasis detection on PSMA PET/CT increased significantly with increase in risk category. PSMA PET/CT sensitivity, specificity, PPV, and NPV for extraprostatic extension, seminal vesicle invasion, and lymph node metastases were 63.16%, 100%, 100%, 36.36%; 55%, 100%, 100%, 25%; and 65.62%, 99.31%, 87.50%, and 97.53%, respectively. Kappa coefficient showed substantial agreement between PSMA PET/CT and histopathological lymph node metastases (κ = 0.734); however, it was just in fair agreement (κ = 0.277) with T stage. PSMA PET/CT overestimated, underestimated, and correct estimated T and N stages in 8.71%, 39.13%, 52.17% and 8.71%, 4.35%, and 86.96% cases, respectively. PSMA PET/CT has potential for initial risk stratification with reasonable correct N stage estimation, however underestimates T stage. Hence, we concluded that PSMA PET/CT should be used as “ first-stop-shop” for staging and initial risk stratification of PCa with regional magnetic resonance imaging in surgically resectable cases.

Low-Risk Prostate Cancer and Tumor Upgrading in the Surgical Specimen: Analysis of Clinical Factors Predicting Tumor Upgrading in a Contemporary Series of Patients Who were Evaluated According to the Modified Gleason Score Grading System

OBJECTIVE

To identify significant clinical factors associated with prostate cancer (PCa) upgrading the low-risk PCa patients graded according to the modified Gleason score system.

MATERIALS AND METHODS

The logistic regression model was used to evaluate the records of 438 patients.

RESULTS

There were 170 cases (38.8%) of low-risk PCa and tumors were upgraded in 111 patients (65.3%). Only prostate specific antigen (PSA) and the proportion of positive cores (P+) were independent predictors of tumor upgrading. Further exploration was investigated by categorizing and regressing PSA (≤ 5.0 vs. > 5.0 ng/ml) and P+ (≤ 0.20 vs. > 0.20). The odds ratio of PSA > 5 ng/ml was 1.32 and of P+ > 0.20 was 2.71. The population was stratified into very low-risk with PSA ≤ 5 ng/ml and P+ ≤ 0.20 (class A), low-risk with PSA > 5 ng/ml and P+ ≤ 0.20 (class B), intermediate risk with PSA ≤ 5 ng/ml and P+ > 0.20 (class C), and high risk with PSA > 5 ng/ml and P+ 0.20 (class D). Upgrading rates were extremely low in class A (9%), extremely high in D (50.5%), and moderate (20%) in B and C.

CONCLUSION

Patients diagnosed with low-risk PCa at biopsy are a heterogeneous population because they include subsets with undetected high-grade disease. Significant clinical predictors of upgrading include the PSA value and P+. In low-risk PCa, we identified a high-risk upgrading subgroup that needed repeat biopsies in order to reclassify the tumor grade and to reassess the clinical risk category.

Utility of preoperative 3 Tesla pelvic phased-array multiparametric magnetic resonance imaging in prediction of extracapsular extension and seminal vesicle invasion of prostate cancer and its impact on surgical margin status: Experience at a Canadian academic tertiary care centre

INTRODUCTION

To evaluate the utility of 3 Tesla (3T) pelvic phased-array (PPA) multiparametric magnetic resonance imaging (mpMRI) to predict extracapsular extension (ECE) and seminal vesicle invasion (SVI) and its subsequent effect on radical prostatectomy (RP) surgical margin status.

METHODS

A retrospective evaluation was conducted of RP patients who underwent preoperative 3T PPA mpMRI (without endorectal coil) based on clinical probability of adverse pathological features. Frequencies, specificity, sensitivity, positive predictive value (PPV), and negative predictive value (NPV) of mpMRI in predicting the status of ECE and SVI were calculated.

RESULTS

Forty-eight consecutive patients were included. Sensitivity, specificity, PPV, and NPV for 3T PPA mpMRI using T₂-weighted sequences with diffusion-weighted imaging (DWI) and dynamic contrast enhanced (DCE) imaging to predict ECE was 39%, 56%, 45%, and 50%, respectively, while SVI prediction was 33%, 95%, 50%, and 91%, respectively. Twelve of the 28 cases predicted as being negative for ECE had positive margins, while two of the 20 cases predicted to be positive for ECE had positive margins. Imaging predicted four cases would have SVI, yet two had positive margins, while of the 44 cases predicted as being negative for SVI, four had positive margins.

CONCLUSIONS

These findings at our centre suggest that the use of 3T PPA mpMRI using T₂-weighted sequences with DWI and DCE in predicting pathological ECE and SVI is of questionable benefit. These mpMRI reports may result in closer dissection of neurovascular bundles and subsequent positive surgical margins. Caution should be exercised when basing intraoperative decisions on mpMRI findings.

Multiparametric magnetic resonance imaging for pre-treatment local staging of prostate cancer: A Cancer Care Ontario clinical practice guideline

INTRODUCTION

The utility of T2-weighted magnetic resonance imaging (MRI) in the local staging of prostate cancer is controversial. Due to the success of multiparametric MRI in cancer localization, there is renewed interested in MRI (± functional sequences) for local staging. Guidance on pre-treatment local staging of prostate cancer by MRI was developed using systematic review methodology and expert consultation.

METHODS

MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, and other databases were searched to identify studies comparing: (1) MRI staging vs. radical prostatectomy staging on diagnostic accuracy outcomes; and (2) MRI staging vs. routine clinical staging on clinical and patient outcomes. Studies meeting inclusion criteria were synthesized by outcome and sensitivity/specificity analysis by tumour location was performed. Evidence quality of included studies was assessed and considered in recommendation formulation.

RESULTS

The literature search identified 2510 citations; 62 studies were included. Analysis of MRI ≥1.5 T plus endorectal coil (ER) (± functional sequences) in the detection of extraprostatic extension or seminal vesicle invasion showed modest sensitivities (≥50%) and excellent specificities (>85%) among patients scheduled for radical prostatectomy. MRI upstaging was shown in 20/21 studies, with large variation in correctness (11-85%). Scarcity of clinical and patient outcomes among studies limited synthesis and evaluation. Quality assessment found non-trivial biases.

CONCLUSIONS

Modest imaging performance was shown for MRI (1.5 T + ER and 3 T ± ER) ± functional sequences in regards to sensitivity. Limitations in study design, reporting of clinical and patient outcomes, and the heterogeneous use of MRI tempered the strength of the recommendations.

Bilateral lymph node micrometastases and seminal vesicle invasion associated with same clinical predictors in localized prostate cancer

AIM

To determine clinical factors associated with multiple bilateral lymph node micrometastases and seminal vesicle invasion (pT3b) in organ-confined prostate cancer (PCa).

METHODS

The study excluded patients under androgen deprivation, with lymph node involvement (cN1 status), and having undergone unilateral pelvic lymph node dissection (PLND) during radical prostatectomy (RP). Lymph node micrometastases were classified as unilateral (pN1m) and bilateral (pN1b). Analysis considered multivariate multinomial logistic regression models.

RESULTS

Between January 2013 and March 2015, 140 patients underwent PLND during RP. Lymph node micrometastases were detected in 28 cases (20%) including pN1m in 19 (13.6%) and pN1b in 9 (6.4%). Independent clinical predictors of pN1b included prostate-specific antigen (PSA, µg/L) >12.5 (odds ratio [OR] = 43.0), proportion of positive biopsy cores (PBC) >0.57 (OR = 6.7), and biopsy Gleason grade (bGG) >3 (OR = 7.5). Independent pT3b predictors included PSA>12.5 (OR = 3.8), PBC>0.57 (OR = 4.1), and bGG>3 (OR = 3.8).

CONCLUSIONS

In cN0 patients with localized PCa undergoing PLND, a nonnegligible rate of multiple lymph node micrometastases was detected (32.2%). In the natural history of PCa, there is a close association between pT3b and pN1b disease. Prostate cancer patients who are at high risk of extraglandular extension need selective pelvic staging by multiparametric magnetic resonance imaging to assess seminal vesicle invasion. Operated patients with pT3b and pNx status need close PSA monitoring because of the high probability of occult multiple bilateral lymph node micrometastases.

Multiparametric prostate MRI: focus on T2-weighted imaging and role in staging of prostate cancer

Multiparametric MRI (mpMRI) represents a growing modality for the non-invasive evaluation of prostate cancer (PCa) and is increasingly being used for patients with persistently elevated PSA and prior negative biopsies, for monitoring patients in active surveillance protocols, for preoperative characterization of cancer for surgical planning, and in planning for MRI-targeted biopsy. The focus of this work is twofold. First, we review the key role of T2-weighted imaging (T2WI) in mpMRI, specifically outlining how it is used for anatomic evaluation of the prostate, detection of clinically significant PCa, assessment of extraprostatic extension (EPE), and mimics of PCa on this sequence. We will also discuss optimal technical acquisition parameters for this sequence and recent technical advancements in T2WI. Second, we will delineate the role that mpMRI plays in the staging of PCa and describe the implications of the information that mpMRI can provide in determining the most appropriate management plan for the patient with PCa.

Role of Multi-Parametric Magnetic Resonance Image and PIRADS Score in Patients with Prostate Cancer Eligible for Active Surveillance According PRIAS Criteria

OBJECTIVE

To evaluate the prognostic role of multiparametric-MRI (mp-MRI) in patients with clinically localized prostate cancer (PCa) eligible for active surveillance (AS) according to Prostate Cancer Research International: Active Surveillance (PRIAS) criteria.

PATIENTS AND METHODS

We analyzed prospectively 73 patients with PCa and PRIAS criteria for low-risk disease. All patients fitted criteria for AS but optioned surgery treatment. The mp-MRI was performed to define the likelihood of malignancy according to the Prostate Imaging Reporting and Data System (PIRADS) score (1-5). Patients were divided in 2 groups: non-visible cancer lesion on MRI (PIRADS 2-3) and visible cancer (PIRADS 4-5). Preoperative clinical data (age, body mass index, prostate specific antigen (PSA) level, positive core biopsy, PSA density (PSAD)) and definitive pathological findings (staging, upgrading, unfavorable disease) were compared between groups. PIRADS score was correlated with pathological data to evaluate the prognostic role of mp-MRI; and preoperative variables and definitive pathology (upgrading, upstaging and unfavorable disease) were also assessed.

RESULTS

PSAD (p = 0.04) and pathological stage (p = 0.03) were significantly associated with the presence of visible disease. Visible disease was significantly associated with upstaging (p = 0.03). Correlation between PIRADS 5 and unfavorable disease was statistically significant (p = 0.02). The mp-MRI had adequate sensibility in detecting upstaging (92%), intermediate for upgrading (76%) and unfavorable disease (76%). Negative predictive value was higher for upstaging than for upgrading or unfavorable disease (96 vs. 68% and 64%). Multivariate logistic regression revealed that PIRADS 5 was a significant predictor of upstaging (p = 0.05, OR 16.12) and unfavorable disease (p = 0.01, OR 6.53).

CONCLUSION

A visible lesion on mp-MRI strongly predicts significant PCa in patients eligible for AS according to PRIAS criteria, based on upstaging and unfavorable disease. We believe that mp-MRI is an important tool and should be added to clinical selection criteria for AS.

Low-Risk Prostate Cancer and Tumor Upgrading to Higher Patterns in the Surgical Specimen. Analysis of Clinical Factors Predicting Tumor Upgrading to Higher Gleason Patterns in a Contemporary Series of Patients Who Have Been Evaluated According to the Modified Gleason Score Grading System

OBJECTIVE

To identify clinical factors associated with prostate cancer (PCA) upgrading to higher patterns of the surgical specimen in low-risk PCA.

MATERIALS AND METHODS

We evaluated the records of 438 patients. The multinomial logistic regression model was used.

RESULTS

Low-risk PCA included 170 cases (38.8%) and tumor upgrading was detected in 111 patients (65.3%) of whom 72 (42.4%) had pathological Gleason patterns (pGP) = 3 + 4 and 39 (22.9%) pGP >3 + 4. Prostate-specific antigen (PSA) and proportion of positive cores (P+) were independent predictors of tumor upgrading to higher patterns. The main difference between upgraded cancers related to PSA and to P+ >0.20. The population was stratified into risk classes by PSA ≤5 μg/l and P+ ≤0.20 (class A), PSA >5 μg/l and P+ ≤0.20 (class B), PSA ≤5 μg/l and P+ >0.20 (class C) and PSA >5 μg/l and P+ 0.20 (class D). Upgrading rates to pGP >3 + 4 were extremely low in class A (5.1%), extremely high in D (53.8%).

CONCLUSIONS

Low-risk PCA is a heterogeneous population with significant rates of undetected high-grade disease. Significant clinical predictors of upgrading to higher patterns include PSA and P+, which identify a very high-risk class that needs repeat biopsies in order to reclassify tumor grade.

Innovations in diagnostic imaging of localized prostate cancer

PURPOSE

In recent years, various imaging modalities have been developed to improve diagnosis, staging, and localization of early-stage prostate cancer (PCa).

METHODS

A MEDLINE literature search of the time frame between 01/2007 and 06/2013 was performed on imaging of localized PCa.

RESULTS

Conventional transrectal ultrasound (TRUS) is mainly used to guide prostate biopsy. Contrast-enhanced ultrasound is based on the assumption that PCa tissue is hypervascularized and might be better identified after intravenous injection of a microbubble contrast agent. However, results on its additional value for cancer detection are controversial. Computer-based analysis of the transrectal ultrasound signal (C-TRUS) appears to detect cancer in a high rate of patients with previous biopsies. Real-time elastography seems to have higher sensitivity, specificity, and positive predictive value than conventional TRUS. However, the method still awaits prospective validation. The same is true for prostate histoscanning, an ultrasound-based method for tissue characterization. Currently, multiparametric MRI provides improved tissue visualization of the prostate, which may be helpful in the diagnosis and targeting of prostate lesions. However, most published series are small and suffer from variations in indication, methodology, quality, interpretation, and reporting.

CONCLUSIONS

Among ultrasound-based techniques, real-time elastography and C-TRUS seem the most promising techniques. Multiparametric MRI appears to have advantages over conventional T2-weighted MRI in the detection of PCa. Despite these promising results, currently, no recommendation for the routine use of these novel imaging techniques can be made. Prospective studies defining the value of various imaging modalities are urgently needed.

Prostate cancer magnetic resonance imaging (MRI): multidisciplinary standpoint

Prostate cancer is the most common cancer diagnosed in men and a leading cause of death. Accurate assessment is a prerequisite for optimal clinical management and therapy selection of prostate cancer. There are several parameters and nomograms to differentiate between patients with clinically insignificant disease and patients in need of treatment. Magnetic resonance imaging (MRI) is a technique which provides more detailed anatomical images due to high spatial resolution, superior contrast resolution, and multiplanar capability. State-of-the-art MRI techniques, such as diffusion weighted imaging (DWI), MR spectroscopic imaging (MRSI), dynamic contrast enhanced MRI (DCE-MRI), improve interpretation of prostate cancer imaging. In this article, we review the major role of MRI in the advanced management of prostate cancer to noninvasively improve tumor staging, biologic potential, treatment planning, therapy response, local recurrence, and to guide target biopsy for clinical suspected cancer with previous negative biopsy. Finally, future challenges and opportunities in prostate cancer management in the area of functional MRI are discussed as well.