Preoperative 3-Tesla multiparametric endorectal magnetic resonance imaging findings and the odds of upgrading and upstaging at radical prostatectomy in men with clinically localized prostate cancer

The Role of Multiparametric MRI (mpMRI) in the Prediction of Adverse Prostate Cancer Pathology in Radical Prostatectomy Specimen

INTRODUCTION

Prostate cancer (PCa) risk stratification is essential in guiding therapeutic decision. Multiparametric magnetic resonance tomography (mpMRI) holds promise in the prediction of adverse pathologies (AP) after prostatectomy (RP). This study aims to identify clinical and imaging markers in the prediction of adverse pathology.

METHODS

Patients with PCa, diagnosed by targeted biopsy after mpMRI and undergoing RP, were included. The predictive accuracy of mpMRI for extraprostatic extension (ECE), seminal vesicle infiltration (SVI), and lymph node positivity was calculated from the final histopathology.

RESULTS

846 patients were involved. Independent risk parameters include imaging findings such as ECE (OR 3.12), SVI (OR 2.55), and PI-RADS scoring (4: OR 2.01 and 5: OR 4.34). mpMRI parameters such as ECE, SVI, and lymph node metastases showed a high prognostic accuracy (73.28% vs. 95.35% vs. 93.38%) with moderate sensitivity compared to the final histopathology. The ROC analysis of our combined scoring system (D'Amico classification, PSA density, and MRI risk factors) improves the prediction of adverse pathology (AUC: 0.73 vs. 0.69).

CONCLUSION

Our study supports the use of mpMRI for comprehensive pretreatment risk assessment in PCa. Due to the high accuracy of factors like ECE, SVI, and PI-RADS scoring, utilizing mpMRI data enabled accurate prediction of unfavorable pathology after RP.

Prostate cancer epidemiology and prognostic factors in the United States

Objective

Using the latest cohort study of prostate cancer patients, explore the epidemiological trend and prognostic factors, and develop a new nomogram to predict the specific survival rate of prostate cancer patients.

Methods

Patients with prostate cancer diagnosed from January 1, 1975 to December 31, 2019 in the Surveillance, Epidemiology, and End Results Program (SEER) database were extracted by SEER stat software for epidemiological trend analysis. General clinical information and follow-up data were also collected from 105 135 patients with pathologically diagnosed prostate cancer from January 1, 2010 to December 1, 2019. The factors affecting patient-specific survival were analyzed by Cox regression, and the factors with the greatest influence on specific survival were selected by stepwise regression method, and nomogram was constructed. The model was evaluated by calibration plots, ROC curves, Decision Curve Analysis and C-index.

Results

There was no significant change in the age-adjusted incidence of prostate cancer from 1975 to 2019, with an average annual percentage change (AAPC) of 0.45 (95% CI:-0.87~1.80). Among the tumor grade, the most significant increase in the incidence of G2 prostate cancer was observed, with an AAPC of 2.99 (95% CI:1.47~4.54); the most significant decrease in the incidence of G4 prostate cancer was observed, with an AAPC of -10.39 (95% CI:-13.86~-6.77). Among the different tumor stages, the most significant reduction in the incidence of localized prostate cancer was observed with an AAPC of -1.83 (95% CI:-2.76~-0.90). Among different races, the incidence of prostate cancer was significantly reduced in American Indian or Alaska Native and Asian or Pacific Islander, with an AAPC of -3.40 (95% CI:-3.97~-2.82) and -2.74 (95% CI:-4.14~-1.32), respectively. Among the different age groups, the incidence rate was significantly increased in 15-54 and 55-64 age groups with AAPC of 4.03 (95% CI:2.73~5.34) and 2.50 (95% CI:0.96~4.05), respectively, and significantly decreased in ≥85 age group with AAPC of -2.50 (95% CI:-3.43~-1.57). In addition, age, tumor stage, race, PSA and gleason score were found to be independent risk factors affecting prostate cancer patient-specific survival. Age, tumor stage, PSA and gleason score were most strongly associated with prostate cancer patient-specific survival by stepwise regression screening, and nomogram prediction model was constructed using these factors. The Concordance indexes are 0.845 (95% CI:0.818~0.872) and 0.835 (95% CI:0.798~0.872) for the training and validation sets, respectively, and the area under the ROC curves (AUC) at 3, 6, and 9 years was 0.7 or more for both the training and validation set samples. The calibration plots indicated a good agreement between the predicted and actual values of the model.

Conclusions

Although there was no significant change in the overall incidence of prostate cancer in this study, significant changes occurred in the incidence of prostate cancer with different characteristics. In addition, the nomogram prediction model of prostate cancer-specific survival rate constructed based on four factors has a high reference value, which helps physicians to correctly assess the patient-specific survival rate and provides a reference basis for patient diagnosis and prognosis evaluation.

Validating the screening criteria for bone metastases in treatment-naïve unfavorable intermediate and high-risk prostate cancer - the prevalence and location of bone- and lymph node metastases

OBJECTIVE

The European Association of Urology (EAU) recommends a bone scan for newly diagnosed unfavorable intermediate- and high-risk prostate cancer. We aimed to validate the screening criteria for bone metastases in patients with treatment-naïve prostate cancer.

METHODS

This single-center retrospective study included all patients with treatment-naïve unfavorable intermediate- or high-risk prostate cancer. All underwent MRI of the lumbar column (T2Dixon) and pelvis (3DT2w, DWI, and T2 Dixon). The presence and location of lymph node and bone metastases were registered according to risk groups and radiological (rad) T-stage. The risk of lymph node metastases was assessed by odds ratio (OR).

RESULTS

We included 390 patients, of which 68% were high-risk and 32% were unfavorable intermediate-risk. In the high-risk group, the rate of regional- and non-regional lymph node metastases was 11% and 6%, respectively, and the rate of bone metastases was 10%. In the unfavorable intermediate-risk group, the rate of regional- and non-regional lymph node metastases was 4% and 0.8%, respectively, and the rate of bone metastases was 0.8%. Metastases occurred exclusively in the lumbar column in 0.5% of all patients, in the pelvis in 4%, and the pelvis and lumbar column in 3%. All patients with bone metastases had radT3-4, and patients with radT3-4 showed a four-fold increased risk of lymph node metastases (OR 4.48, 95% CI: 2.1-9.5).

CONCLUSION

Bone metastases were found in 10% with high-risk prostate cancer and 0.8% with unfavorable intermediate-risk. Therefore, we question the recommendation to screen the unfavorable intermediate-risk group for bone metastases.

KEY POINTS

• The rate of bone metastases was 10% in high-risk patients and 0.8% in the unfavorable intermediate-risk group. • The rate of lymph-node metastases was 17% in high-risk patients and 5% in the unfavorable intermediate-risk group. • No bone metastases were seen in radiologically localized disease.

Current Opinion on the Use of Magnetic Resonance Imaging in Staging Prostate Cancer: A Narrative Review

Accurate staging is critical for treatment planning and prognosis in men with prostate Cancer. Prostate magnetic imaging resonance (MRI) may aid in the staging evaluation by verifying organ-confined status, assessing the status of the pelvic lymph nodes, and establishing the local extent of the tumor in patients being considered for therapy. MRI has a high specificity for diagnosing extracapsular extension, and therefore may impact the decision to perform nerve sparing prostatectomy, along with seminal vesicle invasion and lymph node metastases; however, its sensitivity remains limited. Current guidelines vary significantly regarding endorsing the use of MRI for staging locoregional disease. For high-risk prostate cancer, most guidelines recommend cross sectional imaging, including MRI, to evaluate for more extensive disease that may merit change in radiation field, extended androgen deprivation therapy, or guiding surgical planning. Although MRI offers reasonable performance characteristics to evaluate bone metastases, guidelines continue to support the use of bone scintigraphy. Emerging imaging technologies, including coupling positron emission tomography (PET) with MRI, have the potential to improve the accuracy of prostate cancer staging with the use of novel radiotracers.

Risk of adverse pathological features for intermediate risk prostate cancer: Clinical implications for definitive radiation therapy

BACKGROUND

Intermediate risk prostate cancer represents a largely heterogeneous group with diverse disease extent. We sought to establish rates of adverse pathological features important for radiation planning by analyzing surgical specimens from men with intermediate risk prostate cancer who underwent immediate radical prostatectomy, and to define clinical pathologic features that may predict adverse outcomes.

MATERIALS AND METHODS

A total of 1552 men diagnosed with intermediate risk prostate cancer who underwent immediate radical prostatectomy between 1/1/2005 and 12/31/2015 were reviewed. Inclusion criteria included available preoperative PSA level, pathology reports of transrectal ultrasound-guided prostate biopsy, and radical prostatectomy. Incidences of various pathological adverse features were evaluated. Patient characteristics and clinical disease features were analyzed for their predictive values.

RESULTS

Fifty percent of men with high risk features (defined as PSA >10 but <20 or biopsy primary Gleason pattern of 4) had pathological upstage to T3 or higher disease. The incidence of upgrade to Gleason score of 8 or higher and the incidence of lymph node positive disease was low. Biopsy primary Gleason pattern of 4, and PSA greater than 10 but less than 20, affected adverse pathology in addition to age and percent positive biopsy cores. Older age and increased percentage of positive cores were significant risk factors of adverse pathology.

CONCLUSION

Our findings underscore the importance of comprehensive staging beyond PSA level, prostate biopsy, and CT/bone scan for men with intermediate risk prostate cancer proceeding with radiation in the era of highly conformal treatment.

Extracapsular extension on multiparametric magnetic resonance imaging better predicts pT3 disease at radical prostatectomy compared to perineural invasion on biopsy

INTRODUCTION

Risk assessment for non-organ-confined prostate cancer (PCa) is important in the surgical planning for radical prostatectomy (RP). Perineural invasion (PNI) on prostate biopsy has been associated with adverse pathological outcomes at prostatectomy. Similarly, the identification of suspected extracapsular extension (ECE) on multiparametric magnetic resonance imaging (mpMRI) has been shown to predict non-organ-confined disease. However, no prior study has compared these factors in predicting adverse pathology at prostatectomy. We evaluated mpMRI ECE and prostate biopsy PNI on multivariable analysis to determine their ability to predict pathological stage at time of RP.

METHODS

We retrospectively investigated the prostatectomy database at our institution to identify men who underwent prostate biopsy with pre-biopsy mpMRI and subsequent RP from 2013-2017. Multivariable regression analysis was performed to compare the association of mpMRI ECE (mECE) and PNI on prostate biopsy on the likelihood of finding pT3 disease on pathology post-prostatectomy.

RESULTS

Of a total 454 RP between 2013 and 2017, 191 patients met our inclusion criteria. Stage pT2 and pT3+ were found in 120 (62.8%) and 71 (37.2%) patients, respectively. Patients with mECE had 4.84 cumulative odds of worse pathological stage on RP (p=0.045) compared to PNI on biopsy, which showed cumulative odds of 2.25 (p=0.048). When controlling only for those patients without PNI, mECE was still found to be a significant predictor of pT3 disease at RP (p=0.030); however, in patients without mECE, PNI was not significant (p=0.062).

CONCLUSIONS

While mECE and biopsy PNI were both associated with worse pathological stage on RP, mECE had significantly higher cumulative odds compared to PNI. The significant predictive ability of mECE adds further clinical value to the use of mpMRI in PCa management. While validation in a larger cohort is required, these factors have important clinical implications with regards to early diagnosis of advanced disease and surgical planning.

Prostate cancer local staging using biparametric MRI: assessment and comparison with multiparametric MRI

PURPOSE

The value of adding dynamic contrast-enhanced (DCE) imaging to T2-weighted (T2W) magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) to improve the detection and staging of prostate cancer (PCa) is unclear. The aim of this retrospective study was to compare the diagnostic performance of non-contrast biparametric MRI (bpMRI) with multiparametric MRI (mpMRI), for local staging of PCa.

METHODS

Ninety-two patients who underwent prostate MRI on a 3-Tesla MRI system before radical prostatectomy for PCa were included retrospectively. Four readers independently assigned a Likert score (ranging from 1 to 5) for predicting extra-prostatic extension (EPE) on T2W + DWI (bpMRI) and then on T2W + DWI + DCE imaging (mpMRI). MRI-based staging results were compared with radical prostatectomy histology. A prediction of EPE generalized linear mixed model was used to assess the added-value of DCE and discriminative power of staging accuracy by area under the receiver-operating curve (AUC ROC).

RESULTS

AUC was not significantly improved by DCE (mpMRI, AUC = 0.73 [95%CI: 0.655‒0.827] vs. bpMRI, AUC = 0.76 [95%CI: 0.681‒0.846]). After applying a selection procedure, only MRI criteria were retained in a multivariate model. The following criteria were significantly associated with local extension: localization in the peripheral zone (p < 0.001), maximal diameter of the lesion (<0.0001), curvilinear capsular contact on T2W (p < 0.0001), capsular irregularity on T2W (p < 0.0001), bulging on T2W (p < 0.001) and seminal vesicle hypo-signal (p < 0.001).

CONCLUSION

Use of bpMRI did not result in a decrease in local staging accuracy.

Comparison of Urologist Satisfaction for Different Types of Prostate MRI Reports: A Large Sample Investigation

Objective

To evaluate urologist satisfaction on structured prostate MRI reports, including report with tumor-node-metastasis (TNM) staging (report B) and with Prostate Imaging Reporting and Data System (PI-RADS) score with/without TNM staging (report C, report with PI-RADS score only [report C-a] and report with PI-RADS score and TNM staging [C-b]) compared with conventional free-text report (report A).

Materials and Methods

This was a prospective comparative study. Altogether, 3015 prostate MRI reports including reports A, B, C-a, and C-b were rated by 13 urologists using a 5-point Likert Scale. A questionnaire was used to assess urologist satisfaction based on the following parameters: correctness, practicality, and urologist subjectivity. Kruskal-Wallis H-test followed by Nemenyi test was used to compare urologists' satisfaction parameters for each report type. The rate of urologist-radiologist recalls for each report type was calculated.

Results

Reports B and C including its subtypes had higher ratings of satisfaction than report A for overall satisfaction degree, and parameters of correctness, practicality, and subjectivity (p < 0.05). There was a significant difference between report B and C (p < 0.05) in practicality score, but no statistical difference was found in overall satisfaction degree, and correctness and subjectivity scores (p > 0.05). Compared with report C-b (p > 0.05), report B and C-a (p < 0.05) showed a significant difference in overall satisfaction degree and parameters of practicality and subjectivity. In terms of correctness score, neither report C-a nor C-b had a significant difference with report B (p > 0.05). No statistical difference was found between report C-a and C-b in overall satisfaction degree and all three parameters (p > 0.05). The rate of urologist-radiologist recalls for reports A, B, C-a and C-b were 29.1%, 10.8%, 18.1% and 11.2%, respectively.

Conclusion

Structured reports, either using TNM or PI-RADS are highly preferred over conventional free-text reports and lead to fewer report-related post-hoc inquiries from urologists.

Accuracy of multiparametric magnetic resonance imaging for detecting extracapsular extension in prostate cancer: a systematic review and meta-analysis

OBJECTIVE

To evaluate the diagnostic accuracy of multiparametric MRI (mpMRI) for detecting extracapsular extension (ECE) in patients with prostate cancer (PCa).

METHODS AND MATERIALS

We searched MEDLINE, PubMed, Embase and the Cochrane library up to December 2018. We included studies that used mpMRI to differentiate ECE from organ-confined PCa with a combination of T₂ weighted imaging (T₂WI), diffusion-weighted imaging, and dynamic contrast-enhanced MRI. All studies included had pathological diagnosis with radical prostatectomy. Two reviewers independently assessed the methodological quality of included studies by using Quality Assessment of Diagnostic Accuracy Studies 2 tool. We calculated pooled sensitivity, specificity, positive and negative predictive values, diagnostic odds ratios and receiver operating characteristic curve for mpMRI from 2 × 2 tables.

RESULTS

A total of 17 studies that comprised 3374 participants were included. The pooled data showed a sensitivity of 0.55 (95% confidence interval 0.43, 0.66]) and specificity of 0.87 (95% confidence interval 0.82, 0.91) for extracapsular extension detection in PCa.

CONCLUSION

First, our meta-analysis shows moderate sensitivity and high specificity for mpMRI to differentiate ECE from organ-confined prostate cancer before surgery. Second, our meta-analysis shows that mpMRI had no significant differences in performance compared with the former meta-analysis with use of T₂WI alone or with additional functional MRI.

ADVANCES IN KNOWLEDGE

It is the first meta-analysis to evaluate the accuracy of mpMRI in combination of TWI, diffusion-weightedimaging and dynamiccontrast-enhanced-MRI for extracapsular extension detection.

MRI-Based Radiomics Signature for the Preoperative Prediction of Extracapsular Extension of Prostate Cancer

BACKGROUND

Radiomics approaches based on multiparametric MRI (mp-MRI) have shown high accuracy in prostate cancer (PCa) management. However, there is a need to apply radiomics to the preoperative prediction of extracapsular extension (ECE).

PURPOSE

To develop and validate a radiomics signature to preoperatively predict the probability of ECE for patients with PCa, compared with the radiologists' interpretations.

STUDY TYPE

Retrospective.

POPULATION

In total, 210 patients with pathology-confirmed ECE status (101 positive, 109 negative) were enrolled.

FIELD STRENGTH/SEQUENCE

T₂ -weighted imaging (T₂ WI), diffusion-weighted imaging, and dynamic contrast-enhanced imaging were performed on two 3.0T MR scanners.

ASSESSMENT

A radiomics signature was constructed to predict the probability of ECE prior to radical prostatectomy (RP). In all, 17 stable radiomics features of 1619 extracted features based on T₂ WI were selected. The same images were also evaluated by three radiologists. The predictive performance of the radiomics signature was validated and compared with radiologists' interpretations.

STATISTICAL TESTS

A radiomics signature was developed by a least absolute shrinkage and selection operator (LASSO) regression algorithm. Samples enrolled were randomly divided into two groups (143 for training and 67 for validation). Discrimination, calibration, and clinical usefulness were validated by analysis of the receiver operating characteristic (ROC) curve, calibration curve, and the decision curve, respectively. The predictive performance was then compared with visual assessments of three radiologists.

RESULTS

The radiomics signature yielded an AUC of 0.902 and 0.883 in the training and validation cohort, respectively, and outperformed the visual assessment (AUC: 0.600-0.697) in the validation cohort. Pairwise comparisons demonstrated that the radiomics signature was more sensitive than the radiologists (75.00% vs. 46.88%-50.00%, all P < 0.05), but obtained comparable specificities (91.43% vs. (88.57%-94.29%); P ranged from 0.64-1.00).

DATA CONCLUSION

A radiomics signature was developed and validated that outperformed the radiologists' visual assessments in predicting ECE status.

LEVEL OF EVIDENCE

4 Technical Efficacy Stage: 2 J. Magn. Reson. Imaging 2019;50:1914-1925.

Evaluation of the most optimal multiparametric magnetic resonance imaging sequence for determining pathological length of capsular contact

OBJECTIVES

To assess the most optimal multi-parametric magnetic resonance imaging sequence (Mp-MRI) in determining pathological length of capsular contact (LCC) for the diagnosis of prostate cancer extraprostatic extension (EPE).

METHODS

105 patients with prostate cancer who underwent Mp-MRI of prostate prior to radical prostatectomy were enrolled in this retrospective study. LCC was determined from T2-weighted images (T2WI), Apparent Diffusion Coefficient (ADC) map, dynamic contrast-enhanced MRI (DCE-MRI) separately by two blinded radiologists. The LCCs in patients with and without EPE were compared with Mann Whitney-U test. The relationship between pathological LCC and the LCC that was measured from each Mp-MRI sequences were calculated by using Spearman test. The ability of all individual Mp-MRI sequences in determining pathological LCC was calculated by drawing receiver operator characteristic (ROC) curves. The diagnostic accuracy of LCC based on each MRI sequences for EPE diagnosis was also calculated with ROC curve analysis.

RESULTS

The patients with EPE had longer median LCC than patients without EPE for each Mp-MRI sequences and for both readers. In addition, the LCC showed a broader overlapping between patients with and without EPE on ADC map (reader-1, p = 0.01; reader-2, p = 0.01) when compared with T2WI (reader-1, p = 0.002; reader-2, p = 0.001) and DCE-MRI (reader-1, p = 0.001; reader-2, p = 0.001). LCC based on DCE-MRI showed the strongest correlation with pathological LCC. The area under the curve (AUC) based on LCC was higher when using the DCE-MRI (reader-1: 0.874, p = 0.030; reader-2: 0.862, p = 0.02) than when using T2WI and ADC map in predicting pathological LCC for both readers. While the LCC based on ADC map showed poor diagnostic accuracy, LCC based on T2WI and DCE-MRI had fair diagnostic accuracy for EPE diagnosis.

CONCLUSION

The contact between prostate tumor and capsule seems to be a useful and objective parameter for evaluating the EPE of prostate cancer with Mp-MRI. More specifically, LCC based on DCE-MRI has highest correlation with pathological LCC and has better ability to predict pathological LCC when compared with other Mp-MRI sequences. However, the performance of LCC based on T2WI and DCE-MRI was similar for EPE diagnosis. It seems measurement of LCC from DCE-MRI and measurement of LCC from T2WI does not show any difference in clinical EPE assessment.

Pretreatment Multiparametric Magnetic Resonance Imaging Findings Are More Accurate Independent Predictors of Outcome Than Clinical Variables in Localized Prostate Cancer

PURPOSE

To prospectively determine whether multiparametric magnetic resonance imaging (mpMRI)-based staging is a more accurate independent predictor of outcome than traditional clinical variables for patients undergoing brachytherapy and external beam radiation therapy.

METHODS AND MATERIALS

The primary endpoints were biochemical (nadir plus 2 ng/mL) and metastatic failure. Descriptive, univariate, and multivariate competing risks analyses were performed. The cumulative incidence rates were estimated to describe the cumulative risk of the events of interest. The magnitude of the increased risk was estimated using univariate and multivariate subdistribution hazard ratios.

RESULTS

A total of 185 patients had undergone prospective treatment (123 with high risk and 62 with intermediate risk). The median age was 71 years (range 56-82). Of the patients, 20.5% had mpMRI-determined (mrT) stage mrT1-mrT2b, 37.3% had mrT2c, 31% had mrT3a, and 11.2% had mrT3b. The Gleason score was 6 in 22.2%, 7 in 49.5%, and 8 to 10 in 28.2%. The median baseline prostate-specific antigen was 11.7 ng/mL (range 2.9-153). After a median follow-up period of 46 months (range 16-70), 15 patients (8.1%) had developed biochemical failure and 9 (4.9%) had developed distant metastases. None of the traditional clinical variables (prostate-specific antigen, Gleason score, clinical stage) predicted for biochemical or metastatic failure. The multivariate competing risk analysis demonstrated that the 2 independent predictors of biochemical failure were the presence of extraprostatic extension (EPE; mrT3a; hazard ratio [HR] 4.80; P = .035) and presence of seminal vesicle invasion (SVI; mrT3b; HR 10.17; P = .003) on mpMRI. The only independent predictor of metastatic failure was the percentage of positive cores on prostate biopsy (HR 13.95; P = .014). After excluding patients with SVI, the only independent predictor of biochemical failure and metastatic failure was the presence of EPE (stage mrT3a) on mpMRI (HR 4.36; P = .042; and HR 5.76; P = .010, respectively).

CONCLUSIONS

The pretreatment mpMRI findings might be more accurate independent predictors of the outcome than traditional clinical variables. In particular, the presence of EPE, SVI and a greater percentage of positive cores on biopsy predicted for a worse prognosis.

Diagnostic accuracy of multiparametric magnetic resonance imaging in detecting extracapsular extension in intermediate and high - risk prostate cancer

OBJECTIVES

To evaluate the diagnostic performance of preoperative multiparametric magnetic resonance imaging (mp-MRI) as a predictor of extracapsular extension (ECE) and unfavorable Gleason score (GS) in patients with intermediate and high-risk prostate cancer (PCa).

MATERIALS AND METHODS

Patients with clinically localized PCa who underwent radical prostatectomy (RP) and had preoperative mp-MRI between May-2011 and December-2013. Mp-MRI was evaluated according to the European Society of Urogenital Radiology MRI prostate guidelines by two different readers. Histopathological RP results were the standard reference.

RESULTS

79 patients were included; mean age was 61 and median preoperative prostate-specific antigen (PSA) 7.0. On MRI, 28% patients had ECE evidenced in the mp-MRI, 5% seminal vesicle invasion (SVI) and 4% lymph node involvement (LNI). At RP, 39.2% had ECE, 26.6% SVI and 12.8% LNI. Sensitivity, specificity, accuracy, positive predictive value (PPV), and negative predictive value (NPV) of mp-MRI for ECE were 54.9%, 90.9%, 76%, 81% and 74.1% respectively; for SVI values were 19.1%, 100%, 77.3%, 100% and 76.1% respectively and for LNI 20%, 98.4%, 86.7%, 66.7% and 88.7%.

CONCLUSIONS

Major surgical decisions are made with digital rectal exam (DRE) and ultrasound studies before the use of Mp-MRI. This imaging study contributes to rule out gross extraprostatic extension (ECE, SVI, LNI) without competing with pathological studies. The specificity and NPV are reasonable to decide surgical approach. A highly experienced radiology team is needed to provide accurate estimations of tumor extension and aggressiveness.

Pretreatment 3T multiparametric MRI staging predicts for biochemical failure in high-risk prostate cancer treated with combination high-dose-rate brachytherapy and external beam radiotherapy

PURPOSE

To determine whether pretreatment 3T multiparametric MRI (mpMRI) staging impacts biochemical recurrence-free survival (BRFS) or distant metastasis-free survival (DMFS) for men with high-risk prostate cancer treated with combination high-dose-rate (HDR) brachytherapy and external beam radiation therapy (EBRT).

MATERIALS AND METHODS

This institutional review board-approved retrospective study included a cohort of 37 men with high-risk prostate cancer treated with HDR brachytherapy and EBRT after 3T mpMRI. Kaplan-Meier analysis was used to evaluate whether mpMRI evidence of extracapsular extension or seminal vesicle invasion (SVI) resulted in differences in BRFS or DMFS. Pretreatment and treatment-related variables were evaluated for association with biochemical failure (Phoenix definition) and distant metastatic failure using univariate Cox regression analysis.

RESULTS

The median prostate-specific antigen at diagnosis was 9 ng/mL (range 2-100). Biopsy Gleason score (bGS) was ≤8 in 38% and nine in 62%. Clinical T-category was T1-T2 in 89%, T3a in 8%, and T3b in 3%. With a median followup of 30.6 months, actuarial 3-year BRFS and DMFS were 76% and 86%, respectively. Kaplan-Meier analysis revealed that mpMRI evidence of extracapsular extension or SVI resulted in significantly higher rates of both biochemical recurrence and distant failure. Using Cox regression analysis, only mpMRI evidence of SVI vs. no SVI predicted for biochemical failure (hazard ratio 13.98, p = 0.0055).

CONCLUSIONS

For high-risk prostate cancer treated with combination HDR brachytherapy and EBRT, mpMRI evidence of SVI predicted for biochemical failure, whereas traditional pretreatment variables did not. Therefore, pretreatment 3T mpMRI appears useful for identifying men who may benefit from treatment intensification.

Neurovascular bundle size measured on 3.0-T magnetic resonance imaging is associated with the recovery of erectile function after robot-assisted radical prostatectomy

BACKGROUND AND OBJECTIVE

Erectile dysfunction is one of the complications occurring after radical prostatectomy (RP), and recovery of erectile function is quantitatively related to the preservation of the neurovascular bundles (NVB).We evaluated the significance of NVB area on functional outcomes after RP.

MATERIALS AND METHODS

Preoperative magnetic resonance imaging was performed on 141 patients who underwent bilateral, nerve-sparing, robot-assisted RP for clinically localized prostate cancer (clinically T2N0M0 on magnetic resonance imaging) and were evaluated at least 12 months after surgery. NVB area was measured as a region of interest that coincided with the outline of the maximum area of the posterolateral region of the prostate on T2-weighted axial imaging. Factors associated with functional outcomes were evaluated using logistic regression analysis.

RESULTS

Of 141 patients, 36 patients (25.5%) had no preoperative potency (group 1), 66 patients (46.8%) recovered potency (group 2), and 39 patients (27.7%) did not recover potency (group 3). Although the mean age of the entire cohort was 65.4 years, the mean age of group 1 was greater than groups 2 and 3 (P = 0.001). The NVB area of group 2 was larger than those of groups 1 and 3 (P = 0.001). Potency evaluations involved 105 patients (74.5%; groups 2 and 3), and patients with pre-existing erectile dysfunction were excluded. The median time to potency recovery was 3.0 months after surgery. The multivariable analysis revealed that the NVB area was the only significant factor predictive of potency recovery.

CONCLUSIONS

The NVB area in the posterolateral region of the prostate is an independent factor for predicting potency recovery. The degree of postoperative erectile function can be predicted based on the preoperative NVB area.

Evaluation of MRI for diagnosis of extraprostatic extension in prostate cancer

PURPOSE

To assess the ability of magnetic resonance imaging (MRI) to diagnose extraprostatic extension (EPE) in prostate cancer.

MATERIALS AND METHODS

With Institutional Review Board (IRB) approval, 149 men with 170 ≥0.5 mL tumors underwent preoperative 3T MRI followed by radical prostatectomy (RP) between 2012-2015. Two blinded radiologists (R1/R2) assessed tumors using Prostate Imaging Reporting and Data System (PI-RADS) v2, subjectively evaluated for the presence of EPE, measured tumor size, and length of capsular contact (LCC). A third blinded radiologist, using MRI-RP-maps, measured whole-lesion: apparent diffusion coefficient (ADC) mean/centile and histogram features. Comparisons were performed using chi-square, logistic regression, and receiver operator characteristic (ROC) analysis.

RESULTS

The subjective EPE assessment showed high specificity (SPEC = 75.4/91.3% [R1/R2]), low sensitivity (SENS = 43.3/43.6% [R1/R2]), and area-under (AU) ROC curve = 0.67 (confidence interval [CI] 0.61-0.73) R1 and 0.61 (CI 0.53-0.70) R2; (k = 0.33). PI-RADS v2 scores were strongly associated with EPE (P < 0.001 / P = 0.008; R1/R2) with AU-ROC curve = 0.72 (0.64-0.79) R1 and 0.61 (0.53-0.70) R2; (k = 0.44). Tumors with EPE were larger (18.8 ± 7.8 [median 17, range 6-51] vs. 18.8 ± 4.9 [12, 6-28] mm) and had greater LCC (21.1 ± 14.9 [16, 1-85] vs. 13.6 ± 6.1 [11.5, 4-30] mm); P < 0.001 and 0.002, respectively. AU-ROC for size was 0.73 (0.64-0.80) and LCC was 0.69 (0.60-0.76), respectively. Optimal SENS/SPEC for diagnosis of EPE were: size ≥15 mm = 67.7/66.7% and LCC ≥11 mm = 84.9/44.8%. 10^th -centile ADC and ADC entropy were both associated with EPE (P = 0.02 and < 0.001), with AU-ROC = 0.56 (0.47-0.65) and 0.76 (0.69-0.83), respectively. Optimal SENS/SPEC for diagnosis of EPE with entropy ≥6.99 was 63.3/75.0%. 25^th -centile ADC trended towards being significantly lower with EPE (P = 0.06) with no difference in other ADC metrics (P = 0.25-0.88). Size, LCC, and ADC entropy improved sensitivity but reduced specificity compared with subjective analysis with no difference in overall accuracy (P = 0.38).

CONCLUSION

Measurements of tumor size, capsular contact, and ADC entropy improve sensitivity but reduce specificity for diagnosis of EPE compared to subjective assessment.

LEVEL OF EVIDENCE

3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:176-185.

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.

Unfavorable Intermediate-Risk Prostate Cancer and the Odds of Upgrading to Gleason 8 or Higher at Prostatectomy

BACKGROUND

Some men with unfavorable intermediate-risk prostate cancer (PC) have occult disease with a Gleason score of 8 or higher unrecognized on biopsy because of a sampling error that would change management to long from short course androgen-deprivation therapy in conjunction with radiotherapy. Identifying such men could improve outcomes.

PATIENTS AND METHODS

The study cohort consisted of 136 consecutive men with unfavorable intermediate-risk PC who underwent radical prostatectomy (RP) between 2005 and 2008. We performed logistic regression analysis to identify clinical factors associated with upgrading to a Gleason score of 8 or higher at RP.

RESULTS

Fourteen percent of the men were upgraded to a Gleason score of 8 or higher PC at RP. Both increasing prostate-specific antigen (PSA) (adjusted odds ratio, 1.98; 95% confidence interval, 1.19, 3.30; P = .01) and greatest percentage core length (GPC) (adjusted odds ratio, 1.11; 95% confidence interval, 1.03, 1.19; P < .01) were significantly associated with upgrading. A significant interaction between PSA and GPC was observed (P = .01). Specifically, men with low PSA (< 5 ng/mL) and those with larger GPC (> 70%) were significantly more likely to have a Gleason score of 8 or higher at RP compared to men with low PSA and GPC of 70% or less (35% vs. 0%; P = .01), whereas the same was not true among men with PSA levels ≥ 5 ng/mL (16% vs. 9%; P = .36).

CONCLUSION

In men with unfavorable intermediate-risk PC, a multiparametric magnetic resonance imaging could be considered when the PSA is low and the percentage core length high to identify occult Gleason score 8 or higher disease and change management from short to long course androgen-deprivation therapy and radiotherapy.

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.

PI-RADS Prostate Imaging - Reporting and Data System: 2015, Version 2

The Prostate Imaging - Reporting and Data System Version 2 (PI-RADS™ v2) is the product of an international collaboration of the American College of Radiology (ACR), European Society of Uroradiology (ESUR), and AdMetech Foundation. It is designed to promote global standardization and diminish variation in the acquisition, interpretation, and reporting of prostate multiparametric magnetic resonance imaging (mpMRI) examination, and it is based on the best available evidence and expert consensus opinion. It establishes minimum acceptable technical parameters for prostate mpMRI, simplifies and standardizes terminology and content of reports, and provides assessment categories that summarize levels of suspicion or risk of clinically significant prostate cancer that can be used to assist selection of patients for biopsies and management. It is intended to be used in routine clinical practice and also to facilitate data collection and outcome monitoring for research.

Added Value of Multiparametric Ultrasonography in Magnetic Resonance Imaging and Ultrasonography Fusion-guided Biopsy of the Prostate in Patients With Suspicion for Prostate Cancer

OBJECTIVE

To analyze whether magnetic resonance imaging-ultrasonography (MRI-US) fusion-guided biopsy detects more and clinical significant prostate cancer (PCa) in comparison to conventional transrectal US-guided prostate biopsy (PBX) and to investigate if multiparametric (mp) US during MRI-US fusion can further characterize mpMRI-suspected lesions according to the prostate MRI reporting and data system (PI-RADS).

METHODS

From January 2012 to January 2014, 169 patients with a median of 2 negative conventional PBX and/or initially or consistently elevated prostate-specific antigen levels were prospectively included and underwent 3 T mpMRI. Real-time MRI-US fusion scan was used to biopsy the mpMRI-targeted lesions (n = 316). Scanning by mpUS, including B-mode, power Doppler, strain elastography, and contrast-enhanced US was performed to further characterize those lesions and to score by US modalities resulting in an mpUS score. Afterward, a conventional 10-core PBX was performed. PCa detection based on the results of targeted and conventional PBX was estimated. Performances of single US modalities were analyzed. The mpUS score was also investigated for PCa and PI-RADS score prediction.

RESULTS

Among 169 patients, 71 PCa (42%) were detected. From these 71 cases, clinically significant PCa (Gleason score ≥7) were detected exclusively by MRI-US fusion in 31 from 46 cases (67.4%). The highest sensitivity was observed in contrast-enhanced US (85%) and elastography (80%). The mpUS score predicts PCa and PI-RADS score with an overall accuracy of 86% and 80%, respectively.

CONCLUSION

MRI-US fusion-guided PBX detects more clinically significant PCa compared with conventional TRUS. The mpUS score correlates with PI-RADS in PCa prediction.

Urotensin II receptor on preoperative biopsy is associated with upstaging and upgrading in prostate cancer

AIM

A higher Gleason score was associated with a lower tumor urotensin II receptor (UTII-R) expression in prostate cancer patients.

METHODS

A retrospective review of formalin-fixed paraffin-embedded tumor tissue derived from those who had prostatectomy and matching biopsy specimens was conducted at six Institutions. UTII-R expression was evaluated on biopsy by immunohistochemistry.

RESULTS

A total of 58 subjects undergoing radical prostatectomy were included. At multivariate analysis, low UTII-R expression was a significant predictor of Gleason upgrading, with an odds ratio of 10.3 (95% CI: 1.55-68.4), and of pathology upstaging, with an odds ratio of 11.1 (95% CI: 1.23-100.48).

CONCLUSIONS

UTII-R expression on biopsy was associated with Gleason upgrading and pathology upstaging in prostate cancer patients.

Impact of an Information Technology-Enabled Initiative on the Quality of Prostate Multiparametric MRI Reports

RATIONALE AND OBJECTIVES

Assess the impact of implementing a structured report template and a computer-aided diagnosis (CAD) tool on the quality of prostate multiparametric magnetic resonance imaging (mp-MRI) reports.

MATERIALS AND METHODS

Institutional Review Board approval was obtained for this Health Insurance Portability and Accountability Act-compliant study performed at an academic medical center. The study cohort included all prostate mp-MRI reports (n = 385) finalized 6 months before and after implementation of a structured report template and a CAD tool (collectively the information technology [IT] tools) integrated into the picture archiving and communication system workstation. Primary outcome measure was quality of prostate mp-MRI reports. An expert panel of our institution's subspecialty-trained abdominal radiologists defined prostate mp-MRI report quality as optimal, satisfactory, or unsatisfactory based on documentation of nine variables. Reports were reviewed to extract the predefined quality variables and determine whether the IT tools were used to create each report. Chi-square and Student's t tests were used to compare report quality before and after implementation of IT tools.

RESULTS

The overall proportion of optimal or satisfactory reports increased from 29.8% (47/158) to 53.3% (121/227) (P < .001) after implementing the IT tools. Although the proportion of optimal or satisfactory reports increased among reports generated using at least one of the IT tools (47/158 = [29.8%] vs. 105/161 = [65.2%]; P < .001), there was no change in quality among reports generated without use of the IT tools (47/158 = [29.8%] vs. 16/66 = [24.2%]; P = .404).

CONCLUSIONS

The use of a structured template and CAD tool improved the quality of prostate mp-MRI reports compared to free-text report format and subjective measurement of contrast enhancement kinetic curve.

Evaluation of the European Society of Urogenital Radiology (ESUR) PI-RADS scoring system for assessment of extra-prostatic extension in prostatic carcinoma

INTRODUCTION

To evaluate extra-prostatic extension (EPE) comparing PI-RADS to non-standardized reporting.

MATERIALS AND METHODS

With IRB approval, 145 consecutive patients underwent radical prostatectomy (RP) and multi-parametric (T2W+DWI+DCE) MRI between 2012 and 2013. Eighty patients (66.3% with EPE) were staged without PI-RADS and 65 patients (64.6% with EPE) were staged using a 5-point PI-RADS scoring system. Studies were reported by fellowship-trained radiologists in routine clinical practice. Individual PIRADS scores were assessed using ROC to determine the score which optimized sensitivity/specificity. Diagnostic accuracy for EPE was compared with/without PI-RADS using the McNemar test. Subgroup analysis by radiologist experience was performed using Spearman correlation and chi-square.

RESULTS

Area under ROC curve for EPE using PI-RADS was 0.62 and optimal sensitivity/specificity was achieved with PI-RADS score ≥ 3. Compared to non-standardized reporting, sensitivity for EPE improved with PI-RADS (59.5% [49.1-68.2] vs. 24.5% [16.7-31.2]), p=0.01; with no difference in specificity (68.0% [50.5-82.6]) vs. (75.0% [60.1-87.6]), p=0.06. Overall accuracy improved with PI-RADS (62.7% [49.6-73.6] vs. 42.0% [31.7-50.7%]), p=0.006. Diagnostic accuracy was better among experienced radiologists without PI-RADS (p=0.005); however, there was no difference in accuracy by reader experience using PI-RADS (p=0.24).

CONCLUSION

The PI-RADS criteria for EPE improves sensitivity without reducing specificity. PI-RADS may reduce differences in accuracy by reader experience.

Differential post-prostatectomy cancer-specific survival of occult T3 vs. clinical T3 prostate cancer: Implications for managing patients upstaged on prostate magnetic resonance imaging

PURPOSE/OBJECTIVE

Long-term androgen deprivation therapy (ADT) was proven in randomized trials to be superior to short-term ADT for radiation-managed patients who have clinical T3 (cT3) disease, but it is unknown whether patients with T3 disease seen only on magnetic resonance imaging require similarly aggressive treatment. We attempted to study this issue by analogy by comparing the long-term post-prostatectomy survival of patients with cT3 disease versus cT1/T2 disease upstaged to pathologic T3 disease.

METHODS

The Surveillance, Epidemiology, and End Results (SEER) database was used to identify 60,165 men diagnosed with prostate adenocarcinoma between 1995 and 2002 who underwent prostatectomy. Prostate cancer-specific mortality (PCSM) was evaluated by stage after adjusting for grade, marital status, race, sex, year of diagnosis, and age.

RESULTS

The median follow-up was 10.5 years. Patients with cT1/T2 but pathologic T3a disease had significantly better 10-year PCSM than men with cT3 disease had (3.0% vs. 9.9%, adjusted hazard ratio [AHR] = 0.420, P<0.001), but they had worse PCSM than men with pathologic T2 disease had (3.0% vs. 0.91%, AHR = 2.53, P<0.001). Of patients with occult T3a disease, those with low-grade/intermediate-grade disease (Gleason score 7 or less) had a slightly higher 10-year PCSM when compared with those with pathologic T2 disease (1.34% vs. 0.91%, AHR = 1.69, P<0.001). Patients with cT1/T2 and pathologic T3b disease had similar PCSM as men presenting with cT3 disease (11.0% vs. 9.86%, AHR = 1.14 [0.862, 1.52], P = 0.353).

CONCLUSIONS

Patients with occult T3a disease had less than half the risk of PCSM as those with cT3 disease, and a subset of those men had similar risk as patients with pathologic T2 disease. Therefore, it is possible that radiation-managed patients with low-grade/intermediate-grade T3a disease by magnetic resonance imaging only might not require long-term ADT. However, patients with occult T3b or high-grade occult T3a disease have similar PCSM as that of those presenting with cT3 disease, so they should be treated as aggressively, including long-course ADT when managed by radiation.

Value of preoperative MRI for prostate cancer staging and continence outcomes prior to prostatectomy: A review of the literature

Pelvic imaging in newly diagnosed prostate cancer is primarily used for staging prior to definitive treatment. Over the past decade use of magnetic resonance imaging (MRI) for pre-surgical planning has increased, as well has he technology and methods for performing prostate MRI. To investigate and define the different MRI technologies available and further assess MRI technology ability to predict pathologic stage. Searching PubMed, we identified current published literature, where the cohort population underwent pre-operative MRI followed by prostatectomy. Keywords used in the PubMed literature search included: MRI, prostate cancer, prostate cancer staging, multiparamentric MRI and incontinence. Papers were included for review if they discussed use of MRI prior to prostatectomy and had corresponding pathologic data, staging, incontinence, and surgical outcomes. Primary information noted was MRI sensitivity, specificity and overall accuracy for detecting extracapsular extension (ECE) and seminal vesicle involvement (SVI). Secondary information derived included assessing the surgical influence of staging information, and identifying predictors of urinary incontinence recovery. Review of the literature showed that in regards to extracapsular extension the reported MRI accuracy ranged from 76%-98%, sensitivity from 20%-90% and specificity from 82%-99%. As for seminal vesicle involvement the reported MRI accuracy ranged from 76%-98%, sensitivity from 20%-90% and specificity from 82%-99%. There is a widely varying sensitivity and specificity for both ECE and SVI and the wide variability in the MRI technology used in the literature supports that use of MRI technology for prostate cancer remains investigational.

Multiparametric MRI for localized prostate cancer: lesion detection and staging

Multiparametric MRI of the prostate combines high-resolution anatomic imaging with functional imaging of alterations in normal tissue caused by neoplastic transformation for the identification and characterization of in situ prostate cancer. Lesion detection relies on a systematic approach to the analysis of both anatomic and functional imaging using established criteria for the delineation of suspicious areas. Staging includes visual and functional analysis of the prostate "capsule" to determine if in situ disease is, in fact, organ-confined, as well as the evaluation of pelvic structures including lymph nodes and bones for the detection of metastasis. Although intertwined, the protocol can be optimized depending on whether lesion detection or staging is of the highest priority.

Progress and controversies: Radiation therapy for prostate cancer

Radiation therapy remains a standard treatment option for men with localized prostate cancer. Alone or in combination with androgen-deprivation therapy, it represents a curative treatment and has been shown to prolong survival in selected populations. In this article, the authors review recent advances in prostate radiation-treatment techniques, photon versus proton radiation, modification of treatment fractionation, and brachytherapy-all focusing on disease control and the impact on morbidity. Also discussed are refinements in the risk stratification of men with prostate cancer and how these are better for matching patients to appropriate treatment, particularly around combined androgen-deprivation therapy. Many of these advances have cost and treatment burden implications, which have significant repercussions given the prevalence of prostate cancer. The discussion includes approaches to improve value and future directions for research.

Preoperative magnetic resonance imaging for detecting uni- and bilateral extraprostatic disease in patients with prostate cancer

Objective

The objective of the study was to evaluate the diagnostic accuracy of preoperative magnetic resonance imaging (MRI) for detecting uni- and bilateral extraprostatic disease (T3) in patients with prostate cancer (PCa).

Materials and methods

This prospective study included 199 patients with biopsy-proven PCa who underwent MRI prior to radical prostatectomy from December 2009 to July 2012. Extraprostatic extension and seminal vesicle invasion represented T3 disease, and was classified as uni- (right or left) or bilateral. MRI detection of T3 disease was assessed by descriptive statistics and odds ratio (OR). Whole-mount histopathology was used as the reference standard.

Results

The overall prevalence of pT3 was 105/199 (53 %), unilateral in 81/105 (77 %) and bilateral in 24/105 (23 %). The sensitivity of MRI for predicting pT3 was 76/105 (72 %), specificity 61/94 (65 %), accuracy 137/199 (69 %), and OR 4.8 (95 % CI 2.7–8.8). A complete match with respect to the laterality of pT3 was found in 52/105 (50 %), and the side-specific accuracy was 113/199 (57 %). When unilateral pT3 was found, MRI falsely suggested contralateral T3 in 4/81 (5 %) and bilateral in 8/81 (10 %). When bilateral pT3 was found, MRI falsely suggested unilateral T3 in 12/24 (50 %).

Conclusion

Magnetic resonance imaging (MRI) detected 72 % of all patients with T3 disease, and the accuracy dropped from 69 to 57 % when considering the laterality of T3. Thus far, the MRI technique is not yet adequate to meet the increasing demands of accurate diagnosis of locally advanced disease, and the contemporary MRI staging should be careful.

Impact of intraoperative MRI/TRUS fusion on dosimetric parameters in cT3a prostate cancer patients treated with high-dose-rate real-time brachytherapy

Purpose

The purpose of this study was to evaluate the impact of intraoperative MRI/TRUS fusion procedure in cT3a prostate cancer patients treated with high-dose-rate (HDR) real-time brachytherapy.

Material and methods

Prostate gland, dominant intraprostatic lesions (DILs), and extracapsular extension (ECE) were delineated in the pre-brachytherapy magnetic resonance images (MRI) of 9 consecutive patients. The pre-implant P-CTV_US (prostate clinical target volume) was defined as the prostate seen in the transrectal ultrasound (TRUS) images. The CTV_MR includedthe prostate with the ECE image (ECE-CTV) as defined on the MRI. Two virtual treatment plans were performed based on the MRI/TRUS fusion images, the first one prescribing 100% of the dose to the P-PTV_US, and the second prescribing to the PTV_MR. The implant parameters and dose-volume histogram (DVH) related parameters of the prostate, OARs, and ECE were compared between both plans.

Results

Mean radial distance of ECE was 3.6 mm (SD: 1.1). No significant differences were found between prostate V₁₀₀, V₁₅₀, V₂₀₀, and OARs DVH-related parameters between the plans. Mean values of ECE V₁₀₀, V₁₅₀, and V₂₀₀ were 85.9% (SD: 15.1), 18.2% (SD: 17.3), and 5.85% (SD: 7) when the doses were prescribed to the PTV_US, whereas ECE V₁₀₀, V₁₅₀, and V₂₀₀ were 99.3% (SD: 1.2), 45.8% (SD: 22.4), and 19.6% (SD: 12.6) when doses were prescribed to PTV_MR (p = 0.028, p = 0.002 and p = 0.004, respectively).

Conclusions

TRUS/MRI fusion provides important information for prostate brachytherapy, allowing for better coverage and higher doses to extracapsular disease in patients with clinical stage T3a.

Role of 3.0 T multiparametric MRI in local staging in prostate cancer and clinical implications for radiation oncology

PURPOSE

To evaluate the accuracy of preoperative 3T multiparametric magnetic resonance imaging (3TmMRI) for local staging of prostate cancer and its influence on the decision to change the clinical target volume (CTV), total dose and hormonal therapy when treating prostate cancer patients with radiotherapy.

METHODS

From 2009 to 2013, 150 patients, who had confirmed prostate cancer and underwent a 3TmMRI before treatment with radical prostatectomy or radical radiation therapy, were included. Radiation therapy treatment (CTV, total dose and hormonal therapy) was initially determined on the basis of the clinical information, and radiation therapy plan was reevaluated after 3TmMRI review. The value of preoperative 3TmMRI in local staging and in the decision of radiotherapy treatment according to NCCN risk classification was analyzed.

RESULTS

3TmMRI performed correct, over- and under staging in 78.7 % (37/47), 6.3 % (3/47), 14.8 % patients (7/47), respectively. 3TmMRI identified 6 cT2a, 7 cT2b, 28 cT2c, 3 cT3a, 3 cT3b tumors. At final pathology, 5 tumors were classified as pT2a, 5 as pT2b, 30 as pT2c, 4 as pT3a, 3 as pT3b. After reviewing the MRI reports, the initial radiotherapy and hormonal therapy plan was changed in 33.9 % patients (35/103).

CONCLUSIONS

In our group of patients, 3TmMRI has been a reliable technique providing an optimal staging for prostate cancer. Its routine use could induce important changes in radiation therapy treatments in a significant number of such patients. However, more additional studies are needed to clarify this issue.

The impact of multiparametric pelvic magnetic resonance imaging on risk stratification in patients with localized prostate cancer

OBJECTIVE

To determine the impact of multiparametric magnetic resonance imaging (MP-MRI) of the prostate on established risk stratification criteria in patients with clinically localized adenocarcinoma of the prostate (ACP).

METHODS

The cohort included 71 patients who underwent MP-MRI of the prostate at a tertiary care referral center as part of their initial workup for ACP. Tumor characteristics comprising traditional risk stratification criteria (prostate-specific antigen, clinical T stage, and biopsy Gleason score) were recorded, and the initial National Comprehensive Cancer Network risk group was calculated. The National Comprehensive Cancer Network risk group was then recalculated incorporating MRI findings. The impact of MRI findings on changes in risk group classification was evaluated using the Stuart-Maxwell test. For patients undergoing radical prostatectomy, MRI findings were correlated with pathologic findings.

RESULTS

The cohort included 11 (15.5%), 39 (54.9%), and 21 patients (29.6%) with low-, intermediate-, and high-risk disease, respectively. MRI findings led to risk group upstaging in 12 cases (16.9%). The highest yield was demonstrated in patients with intermediate-risk disease, in whom MRI led to upstaging in 25.6% of patients. There was a significant difference between pre-MRI and post-MRI risk group classifications (P<.01) for the entire cohort. Compared with radical prostatectomy specimens, the specificity of MRI for T3 disease was 92.9%.

CONCLUSION

In our cohort of patients undergoing MP-MRI for previously untreated, clinically localized ACP, MRI findings led to changes in risk stratification in a substantial proportion of patients. Our findings support the use of MP-MRI in the workup of patients with localized ACP.

Efficacy of using three-tesla magnetic resonance imaging diagnosis of capsule invasion for decision-making about neurovascular bundle preservation in robotic-assisted radical prostatectomy

Purpose

To evaluate the efficacy of using 3-tesla (T) magnetic resonance imaging (MRI) diagnosis of extracapsular extension (ECE) for decision-making about neurovascular bundle (NVB) preservation in robot-assisted radical prostatectomy (RARP) for prostate cancer (PC).

Materials and Methods

We prospectively collected data on PC patients (n=67) who underwent preoperative 3-T MRI before RARP. The choice between nerve sparing or resection was based on 3-T MRI findings of ECE. We compared the MRI findings with the pathological data on surgical margins. Our clinical staging in this study was defined only by MRI.

Results

When the data were divided by prostate lobe (right lobe or left lobe, n=134), 3-T MRI showed 28 positive cases of ECE in 134 prostate lobes, allowing NVB preservation in 42 cases (31.3%). Nerve-sparing surgery was achieved in 38.7% of cases in which clinical T2 staging by MRI was reported. The pathological data revealed that 10 of 134 prostate lobes had positive ECE. The overall sensitivity, specificity, positive predictive value, and negative predictive value for predicting stage T3 (positive ECE) by side were 60.0% (12 of 20 sides), 86.0% (98 of 114 sides), 42.9% (12 of 28 sides), and 92.5% (98 of 106 sides), respectively.

Conclusions

Three-T MRI prior to RARP enables the use of ECE diagnosis to guide decision-making about NVB preservation, with comparatively high specificity and negative predictive value. Further prospective studies are underway to reach more definitive conclusions.