Clinical implications of a multiparametric magnetic resonance imaging based nomogram applied to prostate cancer active surveillance

mpMRI Interpretation in Active Surveillance for Prostate Cancer-An overview of the PRECISE score

Active surveillance (AS) is now included in all major guidelines for patients with low-risk PCa and selected patients with intermediate-risk PCa. Several studies have highlighted the potential benefit of multiparametric magnetic resonance imaging (mpMRI) in AS and it has been adopted in some guidelines. However, uncertainty remains about whether serial mpMRI can help to safely reduce the number of required repeat biopsies under AS. In 2017, the European School of Oncology initiated the Prostate Cancer Radiological Estimation of Change in Sequential Evaluation (PRECISE) panel which proposed the PRECISE scoring system to assess the likelihood of radiological tumor progression on serial mpMRI. The PRECISE scoring system remains the only major system evaluated in multiple publications. In this review article, we discuss the current body of literature investigating the application of PRECISE as it is not as yet an established standard in mpMRI reporting. We delineate the strengths of PRECISE and its potential added value. Also, we underline potential weaknesses of the PRECISE scoring system, which might be tackled in future versions to further increase its value in AS.

Gleason Grade Group Concordance between Systematic Template Combining Magnetic Resonance Imaging Fusion Targeted Biopsy and Radical Prostatectomy Specimens: A Comparison of Transperineal and Transrectal Approaches

OBJECTIVE

To evaluate the Gleason grade (GG) discrepancy between biopsy (Bx) techniques (transperineal [TP] /transrectal [TR] approaches or multiparametric magnetic resonance imaging [mpMRI] targeted biopsy [TBx] / standard template biopsies [SBx]) and radical prostatectomy (RP) specimens.

PATIENTS AND METHODS

We identified 310 prostate cancer (PCa) patients who underwent RP following either TP TBx combining SBx (20-core) (n = 105) or TR TBx combining SBx (12-core) (n = 205) from September 2019 to February 2021. The Bx GG was based on the core with the highest GG and clinically significant PCa (csPCa) was defined as grade group 2 or greater prostate adenocarcinoma.

RESULTS

TP combined TBx and SBx (CBx) showed a better GG concordance (63.8% vs 57.1%) than the TR approach, but did not reach a statistical significance. TBx demonstrated a significantly higher csPCa detection than SBx in all patients including both approaches (70.2% vs 63.9%, P < .001). TR TBx showed a significantly higher concordance than TR SBx (52.2% vs 41.5%, P = .0.002) while TP TBx did not differ from TP SBx. TP CBx showed the highest Kappa coefficient (κ =0.48) followed by TR CBx (κ = 0.39). Thirty-eight of 69 (55.1%) cases with a GG1 diagnosis in CBx were upgraded to csPCa in RP. TR approach showed a trend of 2.8-fold risk to upgrade to RP csPCa than TP approach (P = .0.065).

CONCLUSION

The combination of SBx and TBx led to a better pathological concordance and lower upgrading rate for both TP and TR approaches to RP. With more SBx cores, TP CBx showed a better performance than TR CBx.

Prognostic Nomogram of Osteocarcinoma after Surgical Treatment

Purpose

This study aimed to establish a valid prognostic nomogram for osteocarcinoma after surgical management.

Methods

Based on the SEER database, we retrieved the clinical variables of patients confirmed to have osteocarcinoma between 1975 and 2016. Then, we performed univariate and multivariate analyses and constructed a nomogram of overall survival.

Results

Multivariate analysis of the primary cohort revealed that the independent factors for survival were age, grade, pathologic stage, T stage, and surgery performed. All these factors were showed by the nomogram. The correction curve of survival probability showed that the prediction results of nomogram well agreed with the actual observation results. The C index of the nomogram used to predict survival was 0.82; the AUC of 1-year, 3-year, and 5-year survival rates in the training cohort were 0.9, 0.819, and 0.80631, respectively, indicating that the model was accurate and reliable; whether the operation was performed or not; T stage; grade; and age were the main factors affecting the survival of patients. The AUC of the validation cohort for 1 year, 3 years, and 5 years were 0.8, 0.831, and 0.80023, respectively.

Conclusion

The proposed nomogram can more accurately predict the prognosis of patients with osteocarcinoma after surgical management. This could be a potential method that services clinical work.

Role of multi-parametric magnetic resonance imaging fusion biopsy in active surveillance of prostate cancer: a systematic review

Background:

Our goal is to review current literature regarding the role of multi-parametric magnetic resonance imaging (mpMRI) in the active surveillance (AS) of prostate cancer (PCa) and identify trends in rate of reclassification of risk category, performance of fusion biopsy (FB) versus systematic biopsy (SB), and progression-free survival.

Methods:

We performed a comprehensive literature search in PubMed and identified 121 articles. A narrative summary was performed.

Results:

Thirty-two articles were chosen to be featured in this review. SB and FB are complementary in detecting higher-grade disease in follow-up. While FB was more likely than SB to detect clinically significant disease, FB missed 6.4–11% of clinically significant disease. Imaging factors that predicted upgrading include number of lesions on magnetic resonance imaging (MRI), lesion density, and MRI suspicion level.

Conclusion:

Incorporating mpMRI FB in conjunction with SB should be part of contemporary AS protocols. mpMRI should additionally be used routinely for follow-up; however, mpMRI is not currently sensitive enough in detecting disease progression to replace biopsy in the surveillance protocol.

External validation of a prostate cancer nomogram on magnetic resonance/transrectal ultrasound fusion biopsy in men with prior negative systematic biopsy

OBJECTIVE

To observe how the nomogram, which was created by Truong et al, works in an independent patient group by performing external validation.

PATIENTS AND METHODS

One hundred and eighty-one patients who had at least one prior negative 12-core standard systematic biopsy and lesions with PI-RADS scores of 3 or higher that were detected as a result of mpMRI were included in the study. Targeted biopsy with 12-core standard systematic biopsy was performed on all patients. Clinical and pathological features of the patients were recorded. The discrimination, calibration and decision curve analysis were performed to externally validate the nomogram.

RESULTS

A total of 181 patients with previous negative 12-core systematic biopsies were analysed. One hundred and thirty-four patients (74%) had benign pathology. Radiological volume and PI-RADS scores of 4 and 5 were found as independent predictors of benign pathology. The area under the curve (CI 95%) was found to be 0.80 (0.73-0.87), indicating good discrimination. The median residual was calculated as -0.0873, the intercept as -0.0690, the slope as 0.8927 and r² as 0.2586, indicating good calibration. The standardised net benefit of follow-up decisions was found to be 0.54 and 0.36 at the probability threshold of 0.7 and 0.8, respectively.

CONCLUSION

The original model showed good discrimination and calibration with our data. Defining a high probability threshold for clinical use would be appropriate for centres with high benign biopsy rates similar to our centre.

The stanford prostate cancer calculator: Development and external validation of online nomograms incorporating PIRADS scores to predict clinically significant prostate cancer

BACKGROUND

While multiparametric MRI (mpMRI) has high sensitivity for detection of clinically significant prostate cancer (CSC), false positives and negatives remain common. Calculators that combine mpMRI with clinical variables can improve cancer risk assessment, while providing more accurate predictions for individual patients. We sought to create and externally validate nomograms incorporating Prostate Imaging Reporting and Data System (PIRADS) scores and clinical data to predict the presence of CSC in men of all biopsy backgrounds.

METHODS

Data from 2125 men undergoing mpMRI and MR fusion biopsy from 2014 to 2018 at Stanford, Yale, and UAB were prospectively collected. Clinical data included age, race, PSA, biopsy status, PIRADS scores, and prostate volume. A nomogram predicting detection of CSC on targeted or systematic biopsy was created.

RESULTS

Biopsy history, Prostate Specific Antigen (PSA) density, PIRADS score of 4 or 5, Caucasian race, and age were significant independent predictors. Our nomogram-the Stanford Prostate Cancer Calculator (SPCC)-combined these factors in a logistic regression to provide stronger predictive accuracy than PSA density or PIRADS alone. Validation of the SPCC using data from Yale and UAB yielded robust AUC values.

CONCLUSIONS

The SPCC combines pre-biopsy mpMRI with clinical data to more accurately predict the probability of CSC in men of all biopsy backgrounds. The SPCC demonstrates strong external generalizability with successful validation in two separate institutions. The calculator is available as a free web-based tool that can direct real-time clinical decision-making.

The role of multiparametric magnetic resonance imaging in the selection and follow-up of patients undergoing active surveillance for prostate cancer. An European Section of Uro-Technology (ESUT) review

INTRODUCTION

In recent years, active surveillance (AS) has gained popularity as a safe and reasonable option for patients with low-risk, clinically localized prostate cancer.

OBJECTIVE

To summarize the latest information regarding the use of mpMRI in the setting of active surveillance (AS) for the management of prostate cancer (PCa).

EVIDENCE ACQUISITION

A PubMed-based, English literature search was conducted through February 2020. We selected the most relevant original articles, meta-analyses and systematic reviews that could provide important information.

EVIDENCE SYNTHESIS

The great importance of mpMRI of the prostate in the setting of PCa diagnosis is its ability to visualize primarily high-grade cancerous lesions potentially missed on systematic biopsies. In several studies, mpMRI has shown an improved performance over clinically based models for identifying candidates which will benefit the most from AS. Although data on prostate mpMRI during follow-up of men under AS is sparse, it holds the probability to improve significantly AS programs by a more precise selection of optimal candidates, a more accurate identification of disease progression and a reduction in number of biopsies. The goal of reassessment of patients undergoing AS is to find the most effective moment to change attitude to active treatment.

CONCLUSION

The value of mpMRI has been recognized due to its high negative predictive value (NPV) for lesion upgrading in low-risk PCa patients. The improvement in imaging detection, and precise diagnosis with mpMRI could reduce misclassifications at initial diagnosis and during follow-up, reducing the number of biopsies.

Multiparametric MRI in the management of prostate cancer: an update-a narrative review

The growing interest in multiparametric MRI is leading to important changes in the diagnostic process of prostate cancer. MRI-targeted biopsy is likely to become a standard for the diagnosis of prostate cancer in the next years. Despite it is well known that MRI has no role as a staging technique, it is clear that multiparametric MRI may be of help in active surveillance protocols. Noteworthy, MRI in active surveillance is not recommended, but a proper understanding of its potential may be of help in achieving the goals of a delayed treatment strategy. Moreover, the development of minimally invasive techniques, like laparoscopic and robotic surgery, has led to greater expectations as regard to the functional outcomes of radical prostatectomy. Multiparametric MRI may play a role in planning surgical strategies, with the aim to provide the highest oncologic outcome with a minimal impact on the quality of life. We maintain that a proper anatomic knowledge of prostate lesions may allow the surgeon to achieve a better result in planning as well as in performing surgery and help the surgeon and the patient engage in a shared decision in planning a more effective strategy for prostate cancer control and treatment. This review highlights the advantages and the limitations of multiparametric MRI in prostate cancer diagnosis, in active surveillance and in planning surgery.

A novel nomogram to identify candidates for active surveillance amongst patients with International Society of Urological Pathology (ISUP) Grade Group (GG) 1 or ISUP GG2 prostate cancer, according to multiparametric magnetic resonance imaging findings

OBJECTIVES

To develop a novel nomogram to identify candidates for active surveillance (AS) that combines clinical, biopsy and multiparametric magnetic resonance imaging (mpMRI) findings; and to compare its predictive accuracy to, respectively: (i) Prostate Cancer Research International: Active Surveillance (PRIAS) criteria, (ii) Johns Hopkins (JH) criteria, (iii) European Association of Urology (EAU) low-risk classification, and (iv) EAU low-risk or low-volume with International Society of Urological Pathology (ISUP) Grade Group (GG) 2 classification.

PATIENTS AND METHODS

We selected 1837 patients with ISUP GG1 or GG2 prostate cancer (PCa), treated with radical prostatectomy (RP) between 2012 and 2018. The outcome of interest was the presence of unfavourable disease (i.e., clinically significant PCa [csPCa]) at RP, defined as: ISUP GG ≥ 3 and/or pathological T stage (pT) ≥3a and/or pathological N stage (pN) 1. First, logistic regression models including PRIAS, JH, EAU low-risk, and EAU low-risk or low-volume ISUP GG2 binary classifications (not eligible vs eligible) were used. Second, a multivariable logistic regression model including age, prostate-specific antigen density (PSA-D), ISUP GG, and the percentage of positive cores (Model 1) was fitted. Third, Prostate Imaging-Reporting and Data System (PI-RADS) score (Model 2), extracapsular extension (ECE) score (Model 3) and PI-RADS + ECE score (Model 4) were added to Model 1. Only variables associated with higher csPCa rates in Model 4 were retained in the final simplified Model 5. The area under the receiver operating characteristic curve (AUC), calibration plots and decision curve analyses were used.

RESULTS

Of the 1837 patients, 775 (42.2%) had csPCa at RP. Overall, 837 (47.5%), 986 (53.7%), 348 (18.9%), and 209 (11.4%) patients were eligible for AS according to, respectively, the EAU low-risk, EAU low-risk or low-volume ISUP GG2, PRIAS, and JH criteria. The proportion of csPCa amongst the EAU low-risk, EAU low-risk or low-volume ISUP GG2, PRIAS and JH candidates was, respectively 28.5%, 29.3%, 25.6% and 17.2%. Model 4 and Model 5 (in which only PSA-D, ISUP GG, PI-RADS and ECE score were retained) had a greater AUC (0.84), compared to the four proposed AS criteria (all P < 0.001). The adoption of a 25% nomogram threshold increased the proportion of AS-eligible patients from 18.9% (PRIAS) and 11.4% (JH) to 44.4%. Moreover, the same 25% nomogram threshold resulted in significantly lower estimated risks of csPCa (11.3%), compared to PRIAS (Δ: -14.3%), JH (Δ: -5.9%), EAU low-risk (Δ: -17.2%), and EAU low-risk or low-volume ISUP GG2 classifications (Δ: -18.0%).

CONCLUSION

The novel nomogram combining clinical, biopsy and mpMRI findings was able to increase by ~25% and 35% the absolute frequency of patients suitable for AS, compared to, respectively, the PRIAS or JH criteria. Moreover, this nomogram significantly reduced the estimated frequency of csPCa that would be recommended for AS compared to, respectively, the PRIAS, JH, EAU low-risk, and EAU low-risk or low-volume ISUP GG2 classifications.

Interventional therapy in malignant conditions of the prostate

Interventional therapies are emerging modalities for the treatment of localized prostate cancer. Their aim is to reduce the morbidity associated with radical therapies (rT) by minimizing damage to non-cancerous tissue, with priority given to sparing key structures such as the neurovascular bundles, external sphincter, bladder neck, and rectum, while maintaining local cancer control. Interventional ablative technologies deliver energy in different ways to destroy cancer cells. The most widely investigated techniques are brachytherapy, external beam radiotherapy, cryotherapy, and high-intensity focused ultrasound. Although functional outcomes of focal therapies have been encouraging, with generally low rates of urinary incontinence and erectile dysfunction, robust medium- and long-term oncological outcomes are not available for all techniques. To date, major controversies in focal therapy concern appropriate patient selection, efficacy of focal therapies, as well as treatment paradigms based on the dominant index lesion hypothesis. This review articles discusses the current status of interventional therapies and the oncological and functional outcomes.

Magnetic resonance imaging-guided targeted biopsy in risk classification among patients on active surveillance: A diagnostic meta-analysis

BACKGROUND

The aim of this study was to assess the sensitivity and accuracy of magnetic resonance imaging-guided targeted biopsy (MRI-TB) in patients undergoing active surveillance (AS) procedure.

METHODS

We searched databases to identify relevant studies which compared MRI-TB with systemic biopsy for diagnosing prostate cancer in patients on AS. Outcomes included sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), area under the curve (AUC) and publication bias of AS group, confirmatory biopsy group and follow-up biopsy group.

RESULTS

Fourteen articles involving 1693 patients were included. In AS group, the sensitivity was 0.62 (95% confidence interval [CI], 0.57-0.68), specificity was 0.89 (95% CI, 0.87-0.90), NLR was 0.43 (0.31-0.60), PLR was 4.90 (3.50-6.86), DOR was 12.75 (7.22-22.51), and AUC was 0.8645. In confirmatory biopsy group, the sensitivity was 0.67 (0.59-0.74), specificity was 0.89 (0.86-0.91), NLR was 0.42 (0.27-0.65), PLR was 4.94 (3.88-6.30), DOR was 14.54 (9.60-22.02), and AUC was 0.8812. In follow-up biopsy group, the sensitivity was 0.35 (0.22-0.51), specificity was 0.88 (0.82-0.92), NLR was 0.76 (0.52-1.11), PLR was 3.06 (1.71-5.50), DOR was 4.41 (2.15-9.03), and AUC was 0.8367.

CONCLUSION

MRI-TB has a moderate-to-high diagnostic accuracy for diagnosing and reclassifying patients on AS with high specificity and AUC value under the SROC curve.

Contemporary Trends in Magnetic Resonance Imaging at the Time of Prostate Biopsy: Results from a Large Private Insurance Database

BACKGROUND

Magnetic resonance imaging (MRI) of the prostate (MRI-prostate) facilitates better detection of clinically significant prostate cancer (PCa). Yet, the national trends of MRI at the time of prostate biopsy and its ability to increase the detection of PCa in a biopsy-naïve population remain unknown.

OBJECTIVE

To elucidate the contemporary trends of MRI and prostate biopsy, and whether it improved PCa diagnosis among privately insured patients.

DESIGN, SETTING, AND PARTICIPANTS

This was a retrospective cohort study of a large private health insurance database in the USA-the OptumLabs Data Warehouse. We identified all men ≥40 yr of age who underwent index prostate biopsies from 2010 through 2016.

INTERVENTION

MRI-prostate at the time of index biopsy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Utilization of the MRI at the time of biopsy and incident PCa diagnosis constituted the primary outcomes. We enumerated unadjusted and age-specific annual rates of MRI over time to elucidate trends using regression models (trend analysis). Bivariate and multivariable regression analyses identified patient characteristics associated with MRI-prostate, and the association between the use of MRI and PCa diagnosis.

RESULTS AND LIMITATIONS

Overall, 119 202 men underwent index prostate biopsies. Unadjusted annual rates of MRI at the time of biopsy significantly increased from 7 per 1000 biopsies in 2010 to 83 per 1000 biopsies in 2016 (p < 0.001 for trend). Age-specific rates increased across all age groups (40-49, 50-59, 60-65, 66-74, and 75+ yr; all p < 0.001). On multivariable analysis, black patients had a lower likelihood of MRI compared with white patients (odds ratio [OR]: 0.6; p < 0.01). MRI at the time of biopsy was not associated with a higher likelihood of incident PCa compared with traditional systematic biopsy (OR: 1.0; p = 0.7). The retrospective design and the inability to detect clinically significant PCa (Gleason 7+) constitute the limitations of this study.

CONCLUSIONS

While the use of MRI at the time of biopsy rose markedly, it was not associated with a higher detection rate of PCa. Further research is needed to address effective dissemination of MRI and targeted biopsies, and racial disparities.

PATIENT SUMMARY

From 2010 to 2016, our study found a significant rise in the utilization of magnetic resonance imaging of the prostate (MRI-prostate) at the time of index biopsy, although only a minority of patients undergo MRI-prostate. The use of MRI-prostate was not associated with a higher likelihood of diagnosing incident prostate cancer.

Use of multiparametric magnetic resonance imaging in prostate cancer active surveillance

OBJECTIVES

To review the role of multiparametric magnetic resonance imaging (mpMRI) for active surveillance (AS) of prostate cancer.

MATERIALS AND METHODS

We performed a comprehensive search of Medline and Embase databases for relevant articles in the English language. Search terms included 'prostate cancer', 'active surveillance' or 'monitoring', 'expectant management', and 'MRI'. We also reviewed practice guidelines from recognized international associations or societies involved in prostate cancer care. Articles were selected by both authors for relevance to the subject matter.

RESULTS

The ability of mpMRI to visualize primarily high-grade tumours within the prostate may improve risk stratification for men considering AS for prostate cancer. Multiple mostly single-institution studies have found that the addition of mpMRI and a targeted biopsy strategy can improve AS patient selection over standard TRUS biopsy alone. The high negative predictive value of mpMRI may allow men to avoid early repeat biopsy and may offer the possibility to tailor biopsy strategies. The presence of a radiographically positive lesion on mpMRI at baseline is predictive of higher likelihood of radiographic progression over time while on AS.

CONCLUSIONS

MRI has shown promise in both patient selection and monitoring for men who undergo AS for prostate cancer. There are multiple barriers to the widespread use of mpMRI for AS including quality, cost and access to care.

Comparison of Gleason upgrading rates in transrectal ultrasound systematic random biopsies versus US-MRI fusion biopsies for prostate cancer

PURPOSE

Ultrasound-magnetic resonance imaging (US-MRI) fusion biopsy (FB) improves the detection of clinically significant prostate cancer (PCa). We aimed to compare the Gleason upgrading (GU) rates and the concordance of the Gleason scores in the biopsy versus final pathology after surgery in patients who underwent transrectal ultrasound (TRUS) systematic random biopsies (SRB) versus US-MRI FB for PCa.

MATERIALS AND METHODS

A retrospective analysis of data that were collected prospectively from January 2011 to June 2016 from patients who underwent prostate biopsy and subsequent radical prostatectomy. The study cohort was divided into two groups: US-MRI FB (Group A) and TRUS SRB (Group B). US-MRI FB was performed in patients with a previous MRI with a focal lesion with a Likert score ≥3; otherwise, a TRUS SRB was performed.

RESULTS

In total, 73 men underwent US-MRI FB, and 89 underwent TRUS SRB. The GU rate was higher in Group B (31.5% vs. 16.4%; p=0.027). According to the Gleason grade pattern, GU was higher in Group B than in Group A (40.4% vs. 23.3%; p=0.020). Analyses of the Gleason grading patterns showed that Gleason scores 3+4 presented less GU in Group A (24.1% vs. 52.6%; p=0.043). The Bland-Altman plot analysis showed a higher bias in Group B than in Group A (-0.27 [-1.40 to 0.86] vs. -0.01 [-1.42 to 1.39]). In the multivariable logistic regression analysis, the only independent predictor of GU was the use of TRUS SRB (2.64 [1.11 - 6.28]; p=0.024).

CONCLUSIONS

US-MRI FB appears to be related to a decrease in GU rate and an increase in concordance between biopsy and final pathology compared to TRUS SRB, suggesting that performing US-MRI FB leads to greater accuracy of diagnosis and better treatment decisions.

Role of multiparametric magnetic resonance imaging for patients under active surveillance for prostate cancer: a systematic review with diagnostic meta-analysis

BACKGROUND

The use of multiparametric magnetic resonance imaging (mpMRI) in the setting of patients under active surveillance (AS) is promising. In this systematic-review we aimed to analyse the role of mpMRI in patients under AS.

METHODS

A comprehensive literature research for English-language original and review articles, recently published, was carried out using Medline, Scopus and Web of sciences databases until 30 October 2017. The following MeSH terms were used: 'active surveillance', 'prostate cancer', 'multiparametric magnetic resonance imaging'. A diagnostic meta-analysis was performed for 3.0 T mpMRI in predicting disease re-classification.

RESULTS

In total, 226 studies were selected after research and after removal of duplicates. After analysis on inclusion criteria, 43 studies were identified as eligible for this systematic review with a total of 6,605 patients. The timing of MRI during follow-up of AS differed from all studies like criteria for inclusion in the AS protocol. Overall, there was a low risk of bias across all studies. The diagnostic meta-analysis for 1.5 tesla showed a sensitivity of 0.60, negative predictive value (NPV) of 0.75 and a hierarchical summary receiving operating curve (HSROC) of 0.74 while for 3.0 tesla mpMRI a sensitivity of 0.81, a NPV of 0.78 and a HSROC of 0.83.

CONCLUSIONS

Overall, the available evidence suggests that both 1.5 or 3.0 Tesla mpMRI are a valid tool to monitor progression during AS follow-up, showing good accuracy capabilities in detecting PCa re-classification. However, the modality to better define what means 'disease progression' on mpMRI must be further evaluated.

Does the introduction of prostate multiparametric magnetic resonance imaging into the active surveillance protocol for localized prostate cancer improve patient re-classification?

OBJECTIVES

To determine whether replacement of protocol-driven repeat prostate biopsy (PB) with multiparametric magnetic resonance imaging (mpMRI) ± repeat targeted prostate biopsy (TB) when evaluating men on active surveillance (AS) for low-volume, low- to intermediate-risk prostate cancer (PCa) altered the likelihood of or time to treatment, or reduced the number of repeat biopsies required to trigger treatment.

PATIENTS AND METHODS

A total of 445 patients underwent AS in the period 2010-2016 at our institution, with a median (interquartile range [IQR]) follow-up of 2.4 (1.2-3.7) years. Up to 2014, patients followed a 'pre-2014' AS protocol, which incorporated PB, and subsequently, according to the 2014 National Institute for Health and Care Excellence (NICE) guidelines, patients followed a '2014-present' AS protocol that included mpMRI. We identified four groups of patients within the cohort: 'no mpMRI and no PB'; 'PB alone'; 'mpMRI ± TB'; and 'PB and mpMRI ± TB'. Kaplan-Meier plots and log-rank tests were used to compare groups.

RESULTS

Of 445 patients, 132 (30%) discontinued AS and underwent treatment intervention, with a median (IQR) time to treatment of 1.55 (0.71-2.4) years. The commonest trigger for treatment was PCa upgrading after mpMRI and TB (43/132 patients, 29%). No significant difference was observed in the time at which patients receiving a PB alone or receiving mpMRI ± TB discontinued AS to undergo treatment (median 1.9 vs 1.33 years; P = 0.747). Considering only those patients who underwent repeat biopsy, a greater proportion of patients receiving TB after mpMRI discontinued AS compared with those receiving PB alone (29/66 [44%] vs 32/87 [37%]; P = 0.003). On average, a single set of repeat biopsies was needed to trigger treatment regardless of whether this was a PB or TB.

CONCLUSIONS

Replacing a systematic PB with mpMRI ±TB as part of an AS protocol increased the likelihood of re-classifying patients on AS and identifying men with clinically significant disease requiring treatment. mpMRI ±TB as part of AS thereby represents a significant advance in the oncological safety of the AS protocol.

Perceptions of Prostate MRI and Fusion Biopsy of Radiation Oncologists and Urologists for Patients Diagnosed with Prostate Cancer: Results from a National Survey

BACKGROUND

Magnetic resonance imaging (MRI) of the prostate and fusion biopsy have been advanced to improve the detection of clinically significant prostate cancer (PCa). Yet, frequency of their use and contemporary attitudes among radiation oncologists (ROs) and urologists (UROs) remain largely unknown.

OBJECTIVE

We performed a national survey of UROs and ROs to assess the perceived attitudes towards and frequency of prostate MRI and fusion biopsy.

DESIGN, SETTING, AND PARTICIPANTS

We conducted a national survey of 915 ROs and 940 UROs about prostate MRI and fusion biopsy in 2017.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The survey queried respondents about perceptions of prostate MRI and fusion biopsy and inquired about self-reported utilization. Pearson chi-square test and multivariable logistic regression were used to identify physician characteristics associated with survey responses.

RESULTS AND LIMITATIONS

The overall response rate was 37% (n=691). Both UROs and ROs demonstrated similar positive views that MRI with fusion biopsy improves PCa risk stratification (67% vs 71%; p=0.19) and fusion biopsy increases the confidence recommending active surveillance (55% vs 60%; p=0.18). Yet, only a quarter of both specialties reported frequent use of prostate MRI for treatment decisions for low- and intermediate-risk PCa. Compared with respondents practicing in community practices, those in academic practices were more likely to report using prostate MRI for low- (44% vs 19%; adjusted odds ratio [OR]: 3.96; p<0.001) and intermediate-risk PCa (42% vs 24%; adjusted OR: 2.49; p<0.001). Our study was limited by a modestly lower response rate.

CONCLUSIONS

While both specialties have perceived value in favor of prostate MRI and fusion biopsy, only a quarter of respondents report their use in clinical practice. Physicians practicing in academic medical centers had greater self-reported use.

PATIENT SUMMARY

Magnetic resonance imaging of the prostate and targeted biopsies have growing evidence of their use as a superior diagnostic methodology for prostate cancer diagnosis and treatment decisions. Our survey study found that a majority of radiation oncologists and urologists view both favorably in improving prostate cancer detection and treatment decisions. Yet, only a quarter report using it in routine clinical practice for men diagnosed with prostate cancer.

MRI findings guiding selection of active surveillance for prostate cancer: a review of emerging evidence

Active surveillance (AS) for prostate cancer (PCa) is generally considered to be a safe strategy for men with low-risk, localized disease. However, as many as 1 in 4 patients may be incorrectly classified as AS-eligible using traditional inclusion criteria. The use of multiparametric magnetic resonance imaging (mpMRI) may offer improved risk stratification in both the initial diagnostic and disease monitoring setting. We performed a review of recently published studies to evaluate the utility of this imaging modality for this clinical setting. An English literature search was conducted on PubMed for original investigations on localized PCa, AS, and magnetic resonance imaging. Our Boolean criteria included the following terms: PCa, AS, imaging, MRI, mpMRI, prospective, retrospective, and comparative. Our search excluded publication types such as comments, editorials, guidelines, reviews, or interviews. Our literature review identified 71 original investigations. Among these, 52 met our inclusion criteria. Evidence suggests mpMRI improves characterization of clinically significant prostate cancer (csPCa) foci, and the enhanced detection and risk-stratification afforded by this modality may keep men from being inappropriately placed on AS. Use of serial mpMRI may also permit longer intervals between confirmatory biopsies. Multiple studies demonstrate the benefit of MRI-targeted biopsies. The use of mpMRI of the prostate offers improved confidence in risk-stratification for men with clinically low-risk PCa considering AS. While on AS, serial mpMRI and MRI-targeted biopsy aid in the detection of aggressive disease transformation or foci of clinically-significant cancer undetected on prior biopsy sessions.

Multiparametric magnetic resonance imaging: Overview of the technique, clinical applications in prostate biopsy and future directions

Multiparametric magnetic resonance imaging (mpMRI) has managed to change the paradigms on prostate cancer detection and risk classification. The most clear-cut indication of mpMRI in guidelines is the patients with a history of negative biopsy/increasing prostate-specific antigen (PSA), and presence of additional findings supporting its use in non biopsied patients and active surveillance. mpMRI complements standard clinical exam, PSA measurements, and systematic biopsy, and will miss some tumors that lack enough size or change in tissue density. Use of mpMRI is likely to increase, and further developments in the technique will be important for safe adoption of focal therapy concepts. Here we present a brief summary about mpMRI and its use in detection, risk classification and follow-up of prostate cancer.

MR Imaging for Prostate Cancer Screening and Active Surveillance

The current prostate cancer management paradigm has been criticized in recent years for contributing to the overdiagnosis and overtreatment of the disease. Active surveillance is an avenue by which to reduce overtreatment, but patient selection and monitoring remain a challenge. The use of prostate MR imaging has been growing in recent years and has been incorporated into prostate cancer screening and patient selection and monitoring for active surveillance. This review article discusses the current evidence for the use of MR imaging in each of those settings.

Prostate Cancer Imaging and Biomarkers Guiding Safe Selection of Active Surveillance

Background

Active surveillance (AS) is a widely adopted strategy to monitor men with low-risk, localized prostate cancer (PCa). Current AS inclusion criteria may misclassify as many as one in four patients. The advent of multiparametric magnetic resonance imaging (mpMRI) and novel PCa biomarkers may offer improved risk stratification. We performed a review of recently published literature to characterize emerging evidence in support of these novel modalities.

Methods

An English literature search was conducted on PubMed for available original investigations on localized PCa, AS, imaging, and biomarkers published within the past 3 years. Our Boolean criteria included the following terms: PCa, AS, imaging, biomarker, genetic, genomic, prospective, retrospective, and comparative. The bibliographies and diagnostic modalities of the identified studies were used to expand our search.

Results

Our review identified 222 original studies. Our expanded search yielded 244 studies. Among these, 70 met our inclusion criteria. Evidence suggests mpMRI offers improved detection of clinically significant PCa, and MRI-fusion technology enhances the sensitivity of surveillance biopsies. Multiple studies demonstrate the promise of commercially available screening assays for prediction of AS failure, and several novel biomarkers show promise in this setting.

Conclusion

In the era of AS for men with low-risk PCa, improved strategies for proper stratification are needed. mpMRI has dramatically enhanced the detection of clinically significant PCa. The advent of novel biomarkers for prediction of aggressive disease and AS failure has shown some initial promise, but further validation is warranted.

Multi-institutional nomogram predicting benign prostate pathology on magnetic resonance/ultrasound fusion biopsy in men with a prior negative 12-core systematic biopsy

BACKGROUND

Prostate multiparametric magnetic resonance imaging (mpMRI) may be recommended for patients with a prior negative systematic biopsy (SB). However, a proportion of these patients will continue to have no prostate cancer (PCa) identified on magnetic resonance/ultrasound fusion biopsy (FB) despite abnormal mpMRI findings.

METHODS

In this multi-institutional, retrospective study, clinical and mpMRI parameters were assessed for 285 consecutive patients with at least 1 prior negative biopsy who underwent FB for a Prostate Imaging Reporting and Data System (PI-RADS) score of 3 to 5 at the University of Rochester Medical Center from December 2014 to December 2016, or at the University of Alabama at Birmingham from February 2014 to February 2017. Nomograms were generated for predicting benign prostate pathology on both the targeted biopsy and the concurrent SB.

RESULTS

Benign pathology was found in 132 of 285 patients (46.3%). In a multivariate analysis, the predictors of benign prostate pathology on FB were age, prostate-specific antigen, prostate volume, and PI-RADS score. The predicted probabilities were plotted on a receiver operating characteristic curve, and the area under the curve was 0.825. The nomogram demonstrated excellent calibration and a high net benefit in a decision curve analysis. With a theoretical cutoff probability of ≥0.7 used to recommend deferment of FB, 61 of 285 patients (21.4%) would have avoided an unnecessary biopsy, and only 4 of 285 patients (1.4%) with PCa with a Gleason score ≥ 3 + 4 would have been missed.

CONCLUSIONS

False-positive mpMRI examinations may occur in up to 46.3% of patients with a prior negative biopsy. Thus, a multi-institutional nomogram has been developed and validated for predicting benign pathology after FB in patients with a prior negative biopsy, and this may help to reduce the number of unnecessary biopsies in the setting of abnormal mpMRI findings. Cancer 2018;124:278-85. © 2017 American Cancer Society.

An Assessment of Imaging Informatics for Precision Medicine in Cancer

Objectives: Precision medicine requires the measurement, quantification, and cataloging of medical characteristics to identify the most effective medical intervention. However, the amount of available data exceeds our current capacity to extract meaningful information. We examine the informatics needs to achieve precision medicine from the perspective of quantitative imaging and oncology. Methods: The National Cancer Institute (NCI) organized several workshops on the topic of medical imaging and precision medicine. The observations and recommendations are summarized herein. Results: Recommendations include: use of standards in data collection and clinical correlates to promote interoperability; data sharing and validation of imaging tools; clinician's feedback in all phases of research and development; use of open-source architecture to encourage reproducibility and reusability; use of challenges which simulate real-world situations to incentivize innovation; partnership with industry to facilitate commercialization; and education in academic communities regarding the challenges involved with translation of technology from the research domain to clinical utility and the benefits of doing so. Conclusions: This article provides a survey of the role and priorities for imaging informatics to help advance quantitative imaging in the era of precision medicine. While these recommendations were drawn from oncology, they are relevant and applicable to other clinical domains where imaging aids precision medicine.

The role of whole-lesion apparent diffusion coefficient analysis for predicting outcomes of prostate cancer patients on active surveillance

PURPOSE

To explore the role of whole-lesion apparent diffusion coefficient (ADC) analysis for predicting outcomes in prostate cancer patients on active surveillance.

METHODS

This study included 72 prostate cancer patients who underwent MRI-ultrasound fusion-targeted biopsy at the initiation of active surveillance, had a visible MRI lesion in the region of tumor on biopsy, and underwent 3T baseline and follow-up MRI examinations separated by at least one year. Thirty of the patients also underwent an additional MRI-ultrasound fusion-targeted biopsy after the follow-up MRI. Whole-lesion ADC metrics and lesion volumes were computed from 3D whole-lesion volumes-of-interest placed on lesions on the baseline and follow-up ADC maps. The percent change in lesion volume on the ADC map between the serial examinations was computed. Statistical analysis included unpaired t tests, ROC analysis, and Fisher's exact test.

RESULTS

Baseline mean ADC, ADC_{0-10th-percentile}, ADC_{10-25th-percentile}, and ADC_{25-50th-percentile} were all significantly lower in lesions exhibiting ≥50% growth on the ADC map compared with remaining lesions (all P ≤ 0.007), with strongest difference between lesions with and without ≥50% growth observed for ADC_{0-10th-percentile} (585 ± 308 vs. 911 ± 336; P = 0.001). ADC_{0-10th-percentile} achieved highest performance for predicting ≥50% growth (AUC = 0.754). Mean percent change in tumor volume on the ADC map was 62.3% ± 26.9% in patients with GS ≥ 3 + 4 on follow-up biopsy compared with 3.6% ± 64.6% in remaining patients (P = 0.050).

CONCLUSION

Our preliminary results suggest a role for 3D whole-lesion ADC analysis in prostate cancer active surveillance.

Role of prostate magnetic resonance imaging in active surveillance

Active surveillance (AS) has emerged as a beneficial strategy for management of low risk prostate cancer (PCa) and prevention of overtreatment of indolent disease. However, selection of patients for AS using traditional 12-core transrectal prostate biopsy is prone to sampling error and presents a challenge for accurate risk stratification. In fact, around a third of men are upgraded on repeat biopsy which disqualifies them as appropriate AS candidates. This uncertainty affects adoption of AS among patients and physicians, leading to current AS protocols involving repetitive prostate biopsies and unclear triggers for progression to definitive treatment. Prostate magnetic resonance imaging (MRI) has the potential to overcome some of these limitations through localization of significant tumors in the prostate. In conjunction with MRI-targeted prostate biopsy, improved sampling and detection of clinically significant PCa can help streamline the process of selecting suitable men for AS and early exclusion of men who require definitive treatment. MRI can also help minimize the invasive nature of monitoring for disease progression while on AS. Men with stable MRI findings have high negative predictive value for Gleason upgrade on subsequently biopsy, suggesting that men may potentially be monitored by serial MRI examinations with biopsy reserved for significant changes on imaging. Targeted biopsy on AS also allows for specific sampling of concerning lesions, although further data is necessary to evaluate the relative contribution of systematic and targeted biopsy in detecting the 25-30% of men who progress on AS. Further research is also warranted to better understand the nature of clinically significant cancers that are missed on MRI and why certain men have progression of disease that is not visible on prostate MRI. Consensus is also needed over what constitutes progression on MRI, when prostate biopsy can be safely avoided, and how to best utilize this additional information in current AS protocols. Despite these challenges, prostate MRI, either alone or in conjunction with MRI-targeted prostate biopsy, has the potential to significantly improve our current AS paradigm and rates of AS adoption among patients moving forward.

Multi-parametric magnetic resonance imaging as a management decision tool

The ability to image the prostate accurately and better characterize cancerous lesions makes multiparametric magnetic resonance imaging (mpMRI) an invaluable tool to improve management of localized prostate cancer (PCa). Improved risk stratification is warranted given the evidence of significant overtreatment of indolent PCa. mpMRI can more accurately rule out clinically significant PCa in men deciding between surveillance and definitive treatment to reduce overtreatment. mpMRI improves detection of clinically significant PCa, which helps minimize sampling error, a major limitation of the traditional diagnostic paradigm. Aside from helping determine candidacy for initial surveillance vs. treatment, mpMRI is a useful tool for following men on active surveillance (AS) with the potential to reduce the need for serial biopsies. When definitive treatment is warranted, mpMRI can be used to determine the local extent of disease. This provides information that is useful in the treatment decision, counseling about outcomes, and surgical planning. While mpMRI is a significant step forward in PCa management, it is necessary to understand its limitations. mpMRI and MRI-guided fusion biopsy techniques still do not detect all clinically significant tumors. The utility of current mpMRI techniques is limited by the multifocal nature of PCa with poor detection of non-index lesions, inaccurate estimation of tumor size and geometry, and the need for interpretation by specialized radiologists. The role of mpMRI will continue to expand as improvements in technology and experience help overcome these limitations.

Role of Imaging in the Era of Precision Medicine

Precision medicine is an emerging approach for treating medical disorders, which takes into account individual variability in genetic and environmental factors. Preventive or therapeutic interventions can then be directed to those who will benefit most from targeted interventions, thereby maximizing benefits and minimizing costs and complications. Precision medicine is gaining increasing recognition by clinicians, healthcare systems, pharmaceutical companies, patients, and the government. Imaging plays a critical role in precision medicine including screening, early diagnosis, guiding treatment, evaluating response to therapy, and assessing likelihood of disease recurrence. The Association of University Radiologists Radiology Research Alliance Precision Imaging Task Force convened to explore the current and future role of imaging in the era of precision medicine and summarized its finding in this article. We review the increasingly important role of imaging in various oncological and non-oncological disorders. We also highlight the challenges for radiology in the era of precision medicine.

Role of MRI in the Risk Assessment of Primary Prostate Cancer

A successful paradigm shift toward personalized management strategies for patients with prostate cancer (PCa) is heavily dependent on the availability of noninvasive diagnostic tools capable of accurately establishing the true extent of disease at the time of diagnosis and estimating the risk of subsequent disease progression and related mortality. Although there is still considerable scope for improvement in its diagnostic, predictive, and prognostic capabilities, multiparametric prostate magnetic resonance imaging (MRI) is currently regarded as the imaging modality of choice for local staging of PCa. A negative MRI, that is, the absence of any MRI-visible intraprostatic lesion, has a high negative predictive value for the presence of clinically significant PCa and can substantiate the consideration of active surveillance as a preferred initial management approach. MRI-derived quantitative and semi-quantitative parameters can be utilized to noninvasively characterize MRI-visible prostate lesions and identify those patients who are most likely to benefit from radical treatment, and differentiate them from patients with benign or indolent prostate pathology that may also be visible on MRI. This literature review summarizes current strategies how MRI can be used to determine a tailored management strategy for an individual patient.

Integration of multiparametric MRI into active surveillance of prostate cancer

Prostate cancer is the most common noncutaneous cancer in men though many men will not die of this disease and may not require definitive treatment. Active surveillance (AS) is an increasingly utilized potential solution to the issue of overtreatment of prostate cancer. Traditionally, prostate cancer patients have been stratified into risk groups based on clinical stage on digital rectal examination, prostate-specific antigen and biopsy Gleason score, though each of these variables has significant limitations. This review will discuss the potential role for prostate multiparametric MRI and targeted biopsy techniques incorporating MRI in the selection of candidates for AS, monitoring patients on AS and as triggers for definitive treatment.

Predictive models and risk of biopsy progression in active surveillance patients

OBJECTIVE

To analyze the performance of different radical prostatectomy-based prognostic tools in predicting the biopsy progression in our active surveillance cohort.

MATERIALS AND METHODS

We analyzed 326 patients with biopsy Gleason grade≤6,≤2 positive biopsy cores,≤20% tumor present in any core, prostate-specific antigen<15ng/dl, and clinical stages T1-T2a all of whom had at least single surveillance biopsy. Probabilities of pathologically relatively aggressive disease were estimated using Partin and Dinh risk tables and Kattan, Truong, and Kulkarni nomograms for each individual patient. Using these predictions, performance of these tools was quantified regarding discrimination, stratification at different cut-points, calibration, and the clinical net benefit.

RESULTS

Predictions of Partin and Dinh tables were not associated with the biopsy progression. The predictive value of Kattan and Truong nomograms was higher when compared with the other tools, although it was significant only on the first and second surveillance biopsies. Both nomograms were able to identify low- and high-risk subgroups within the cohort. Kattan nomogram demonstrated better correlation with the observed rate of progression over the first 3 biopsies and higher clinical net benefit.

CONCLUSION

Kattan and Truong nomograms demonstrated the best performance in predicting biopsy progression, although their value was largely limited to the first 2 surveillance biopsies. Both tools were able to stratify patients into subgroups with different risks of progression. These nomograms have important differences, which suggest that a more effective predictive model combining the strong sides of both tools and possibly some other variables could be developed.

Primary Gleason pattern upgrading in contemporary patients with D'Amico low-risk prostate cancer: implications for future biomarkers and imaging modalities

OBJECTIVE

To retrospectively assess the rate of high-grade primary Gleason upgrading (HGPGU) to primary Gleason pattern 4 or 5 in a contemporary cohort of patients with D'Amico low-risk prostate cancer including those who fulfilled Prostate Cancer Research International Active Surveillance (PRIAS) criteria, and to develop a tool for HGPGU prediction. HGPGU is a contraindication in most active surveillance (AS) and focal therapy protocols.

PATIENTS AND METHODS

In all, 10 616 patients with localised prostate cancer were treated at a high-volume European tertiary care centre from 2010 to 2015 with radical prostatectomy. Analyses were restricted to 1 819 patients with D'Amico low-risk prostate cancer (17.1%) with prostate-specific antigen (PSA) levels of <10.0 ng/mL, cT1c-cT2a and Gleason score ≤6, and were repeated within 772 of the men (7.3%) who fulfilled the PRIAS criteria for AS (PSA level of ≤10 ng/mL, T1c-T2, Gleason score ≤6, PSA density (PSAD) of <0.2 ng/mL² , ≤2 positive cores). Uni- and multivariable logistic regression models were fitted, testing predictors of HGPGU. The final logistic regression model was based on the most informative variables.

RESULTS

There was HGPGU in 88 (4.8%) patients with D'Amico low-risk prostate cancer and in 32 (4.1%) of the subgroup who were PRIAS eligible. Multivariable analysis predicting HGPGU for the patients with D'Amico low-risk yielded three independent predictors: age, PSAD, and clinical tumour stage (P = 0.008, P = 0.005 and P = 0.021, respectively). Within the same patients, the model using all vs the most informative variables resulted in area under the curves (AUCs) of 69.2% and 68.3%, respectively. Multivariable analysis of those who were PRIAS eligible, yielded age and number of positive cores as independent predictors of HGPGU (P = 0.002 and P = 0.049, respectively; AUC 64.9%).

CONCLUSIONS

The low accuracy (invariably <70%) for HGPGU prediction in both patients with D'Amico low-risk prostate cancer and PRIAS eligibility indicates that these variables have poor predictive ability in contemporary patients. Despite HGPGU being a rare phenomenon, it may have life threatening implications and consequently alternatives such as biomarkers, genetic markers, or imaging modalities at re-biopsy are needed.

Risk stratification of prostate cancer utilizing apparent diffusion coefficient value and lesion volume on multiparametric MRI

PURPOSE

To evaluate the performance of apparent diffusion coefficient (ADC) and lesion volume in potentially risk-stratifying patients with prostate cancer (PCa).

MATERIALS AND METHODS

Men with elevated prostate-specific antigen or abnormal digital rectal exam underwent a 3T multiparametric magnetic resonance imaging (mpMRI) with endorectal coil. ADC maps were calculated using b values of 0, 500, 1000, and 1500; additional images were obtained with b value of 2000. We prospectively enrolled 312 men with lesions suspicious for cancer (suspicion score 2-5) on mpMRI. MRI/ultrasound fusion-guided prostate biopsies were performed. Mean ADC of suspicious lesions were correlated against lesion volume, Gleason and D'Amico risk.

RESULTS

The cancer detection rate of fusion biopsy per lesion was 45.6% (206/452). Cancerous lesions were larger (median volume: 0.40 vs. 0.30 cm³ ; P = 0.016). The median ADC (×10^-6 mm² /sec) for lesions negative and positive for PCa were 984.5 and 666.5, respectively (P < 0.0001). The AUC of ADC in predicting PCa was 0.79. Larger lesions were associated with higher risk PCa (Gleason and D'Amico) and lower ADC (all P < 0.0001).

CONCLUSION

The mean ADC of suspicious lesions on mpMRI was inversely correlated, while lesion volume had a direct correlation with PCa detection. Future follow-up studies are needed to assess longitudinal cancer risks of suspicious mpMRI lesions.

LEVEL OF EVIDENCE

2 J. Magn. Reson. Imaging 2017;45:610-616.

Preoperative Multiparametric Magnetic Resonance Imaging Predicts Biochemical Recurrence in Prostate Cancer after Radical Prostatectomy

Objectives

To evaluate the utility of preoperative multiparametric magnetic resonance imaging (MP-MRI) in predicting biochemical recurrence (BCR) following radical prostatectomy (RP).

Materials/Methods

From March 2007 to January 2015, 421 consecutive patients with prostate cancer (PCa) underwent preoperative MP-MRI and RP. BCR-free survival rates were estimated using the Kaplan-Meier method. Cox proportional hazards models were used to identify clinical and imaging variables predictive of BCR. Logistic regression was performed to generate a nomogram to predict three-year BCR probability.

Results

Of the total cohort, 370 patients met inclusion criteria with 39 (10.5%) patients experiencing BCR. On multivariate analysis, preoperative prostate-specific antigen (PSA) (p = 0.01), biopsy Gleason score (p = 0.0008), MP-MRI suspicion score (p = 0.03), and extracapsular extension on MP-MRI (p = 0.03) were significantly associated with time to BCR. A nomogram integrating these factors to predict BCR at three years after RP demonstrated a c-index of 0.84, outperforming the predictive value of Gleason score and PSA alone (c-index 0.74, p = 0.02).

Conclusion

The addition of MP-MRI to standard clinical factors significantly improves prediction of BCR in a post-prostatectomy PCa cohort. This could serve as a valuable tool to support clinical decision-making in patients with moderate and high-risk cancers.

Multiparametric magnetic resonance imaging: Current role in prostate cancer management

Digital rectal examination, serum prostate-specific antigen screening and transrectal ultrasound-guided biopsy are conventionally used as screening, diagnostic and surveillance tools for prostate cancer. However, they have limited sensitivity and specificity. In recent years, the role of multiparametric magnetic resonance imaging has steadily grown, and is now part of the standard clinical management in many institutions. In multiparametric magnetic resonance imaging, the morphological assessment of T2-weighted imaging is correlated with diffusion-weighted imaging, dynamic contrast-enhanced imaging perfusion and/or magnetic resonance spectroscopic imaging. Multiparametric magnetic resonance imaging is currently regarded as the most sensitive and specific imaging technique for the evaluation of prostate cancer, including detection, staging, localization and aggressiveness evaluation. This article presents an overview of multiparametric magnetic resonance imaging, and discusses the current role of multiparametric magnetic resonance imaging in the different fields of prostate cancer management.

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.

The Efficacy of Multiparametric Magnetic Resonance Imaging and Magnetic Resonance Imaging Targeted Biopsy in Risk Classification for Patients with Prostate Cancer on Active Surveillance

PURPOSE

We determined whether multiparametric magnetic resonance imaging targeted biopsies may replace systematic biopsies to detect higher grade prostate cancer (Gleason score 7 or greater) and whether biopsy may be avoided based on multiparametric magnetic resonance imaging among men with Gleason 3+3 prostate cancer on active surveillance.

MATERIALS AND METHODS

We identified men with previously diagnosed Gleason score 3+3 prostate cancer on active surveillance who underwent multiparametric magnetic resonance imaging and a followup prostate biopsy. Suspicion for higher grade cancer was scored on a standardized 5-point scale. All patients underwent a systematic biopsy. Patients with multiparametric magnetic resonance imaging regions of interest also underwent magnetic resonance imaging targeted biopsy. The detection rate of higher grade cancer was estimated for different multiparametric magnetic resonance imaging scores with the 3 biopsy strategies of systematic, magnetic resonance imaging targeted and combined.

RESULTS

Of 206 consecutive men on active surveillance 135 (66%) had a multiparametric magnetic resonance imaging region of interest. Overall, higher grade cancer was detected in 72 (35%) men. A higher multiparametric magnetic resonance imaging score was associated with an increased probability of detecting higher grade cancer (Wilcoxon-type trend test p <0.0001). Magnetic resonance imaging targeted biopsy detected higher grade cancer in 23% of men. Magnetic resonance imaging targeted biopsy alone missed higher grade cancers in 17%, 12% and 10% of patients with multiparametric magnetic resonance imaging scores of 3, 4 and 5, respectively.

CONCLUSIONS

Magnetic resonance imaging targeted biopsies increased the detection of higher grade cancer among men on active surveillance compared to systematic biopsy alone. However, a clinically relevant proportion of higher grade cancer was detected using only systematic biopsy. Despite the improved detection of disease progression using magnetic resonance imaging targeted biopsy, systematic biopsy cannot be excluded as part of surveillance for men with low risk prostate cancer.

Multiparametric MRI and targeted prostate biopsy: Improvements in cancer detection, localization, and risk assessment

Introduction

Multiparametric-MRI (mp-MRI) is an evolving noninvasive imaging modality that increases the accurate localization of prostate cancer at the time of MRI targeted biopsy, thereby enhancing clinical risk assessment, and improving the ability to appropriately counsel patients regarding therapy.

Material and methods

We used MEDLINE/PubMed to conduct a comprehensive search of the English medical literature. Articles were reviewed, data was extracted, analyzed, and summarized. In this review, we discuss the mp-MRI prostate exam, its role in targeted prostate biopsy, along with clinical applications and outcomes of MRI targeted biopsies.

Results

Mp-MRI, consisting of T2-weighted imaging, diffusion-weighted imaging, dynamic contrast-enhanced imaging, and possibly MR spectroscopy, has demonstrated improved specificity in prostate cancer detection as compared to conventional T2-weighted images alone. An MRI suspicion score has been developed and is depicted using an institutional Likert or, more recently, a standardized reporting scale (PI-RADS). Techniques of MRI-targeted biopsy include in-gantry MRI guided biopsy, TRUS-guided visual estimation biopsy, and software co-registered MRI-US guided biopsy (MRI-US fusion). Among men with no previous biopsy, MRI-US fusion biopsy demonstrates up to a 20% increase in detection of clinically significant cancers compared to systematic biopsy while avoiding a significant portion of low risk disease. These data suggest a potential role in reducing over-detection and, ultimately, over-treatment. Among men with previous negative biopsy, 72–87% of cancers detected by MRI targeted biopsy are clinically significant. Among men with known low risk cancer, repeat biopsy by MR-targeting improves risk stratification in selecting men appropriate for active surveillance secondarily reducing the need for repetitive biopsy during surveillance.

Conclusions

Use of mp-MRI for targeting prostate biopsies has the potential to reduce the sampling error associated with conventional biopsy by providing better disease localization and sampling. MRI-ultrasound fusion-targeted prostate biopsy may improve the identification of clinically significant prostate cancer while limiting detection of indolent disease, ultimately facilitating more accurate risk stratification. Literature supports the clinical applications of MRI-targeted biopsy in men who have never been biopsied before, those with a prior negative biopsy, and those with low risk disease considering active surveillance.

Current role of multiparametric magnetic resonance imaging for prostate cancer

Multiparametric magnetic resonance imaging (mp-MRI) has shown promising results in diagnosis, localization, risk stratification and staging of clinically significant prostate cancer, and targeting or guiding prostate biopsy. mp-MRI consists of T2-weighted imaging (T2WI) combined with several functional sequences including diffusion-weighted imaging (DWI), perfusion or dynamic contrast-enhanced imaging (DCEI) and spectroscopic imaging. Recently, mp-MRI has been used to assess prostate cancer aggressiveness and to identify anteriorly located tumors before and during active surveillance. Moreover, recent studies have reported that mp-MRI is a reliable imaging modality for detecting local recurrence after radical prostatectomy or external beam radiation therapy. Because assessment on mp-MRI can be subjective, use of the newly developed standardized reporting Prostate Imaging and Reporting Archiving Data System (PI-RADS) scoring system and education of specialist radiologists are essential for accurate interpretation. This review focuses on the current place of mp-MRI in prostate cancer and its evolving role in the management of prostate cancer.

Multiparametric magnetic resonance imaging for prostate cancer: A review and update for urologists

Recently, imaging of prostate cancer has greatly advanced since the introduction of multiparametric magnetic resonance imaging (mpMRI). mpMRI consists of T2-weighted sequences combined with several functional sequences including diffusion-weighted imaging, dynamic contrast-enhanced imaging, and/or magnetic resonance spectroscopy imaging. Interest has been growing in mpMRI because no single MRI sequence adequately detects and characterizes prostate cancer. During the last decade, the role of mpMRI has been expanded in prostate cancer detection, staging, and targeting or guiding prostate biopsy. Recently, mpMRI has been used to assess prostate cancer aggressiveness and to identify anteriorly located tumors before and during active surveillance. Moreover, recent studies have reported that mpMRI is a reliable imaging modality for detecting local recurrence after radical prostatectomy or external beam radiation therapy. In this regard, some urologic clinical practice guidelines recommended the use of mpMRI in the diagnosis and management of prostate cancer. Because mpMRI is the evolving reference standard imaging modality for prostate cancer, urologists should acquire cutting-edge knowledge about mpMRI. In this article, we review the literature on the use of mpMRI in urologic practice and provide a brief description of techniques. More specifically, we state the role of mpMRI in prostate biopsy, active surveillance, high-risk prostate cancer, and detection of recurrence after radical prostatectomy.