Xiaosong Meng

Relationship Between Prebiopsy Multiparametric Magnetic Resonance Imaging (MRI), Biopsy Indication, and MRI-ultrasound Fusion–targeted Prostate Biopsy Outcomes

BACKGROUND Increasing evidence supports the use of magnetic resonance imaging (MRI)-ultrasound fusion-targeted prostate biopsy (MRF-TB) to improve the detection of clinically significant prostate cancer (PCa) while limiting detection of indolent disease compared to systematic 12-core biopsy (SB). OBJECTIVE To compare MRF-TB and SB results and investigate the relationship between biopsy outcomes and prebiopsy MRI. DESIGN, SETTING, AND PARTICIPANTS Retrospective analysis of a prospectively acquired cohort of men presenting for prostate biopsy over a 26-mo period. A total of 601 of 803 consecutively eligible men were included. INTERVENTIONS All men were offered prebiopsy MRI and assigned a maximum MRI suspicion score (mSS). Men with an MRI abnormality underwent combined MRF-TB and SB. OUTCOMES Detection rates for all PCa and high-grade PCa (Gleason score [GS] ≥7) were compared using the McNemar test. RESULTS AND LIMITATIONS MRF-TB detected fewer GS 6 PCas (75 vs 121; p<0.001) and more GS ≥7 PCas (158 vs 117; p<0.001) than SB. Higher mSS was associated with higher detection of GS ≥7 PCa (p<0.001) but was not correlated with detection of GS 6 PCa. Prediction of GS ≥7 disease by mSS varied according to biopsy history. Compared to SB, MRF-TB identified more GS ≥7 PCas in men with no prior biopsy (88 vs 72; p=0.012), in men with a prior negative biopsy (28 vs 16; p=0.010), and in men with a prior cancer diagnosis (42 vs 29; p=0.043). MRF-TB detected fewer GS 6 PCas in men with no prior biopsy (32 vs 60; p<0.001) and men with prior cancer (30 vs 46; p=0.034). Limitations include the retrospective design and the potential for selection bias given a referral population. CONCLUSIONS MRF-TB detects more high-grade PCas than SB while limiting detection of GS 6 PCa in men presenting for prostate biopsy. These findings suggest that prebiopsy multiparametric MRI and MRF-TB should be considered for all men undergoing prostate biopsy. In addition, mSS in conjunction with biopsy indications may ultimately help in identifying men at low risk of high-grade cancer for whom prostate biopsy may not be warranted. PATIENT SUMMARY We examined how magnetic resonance imaging (MRI)-targeted prostate biopsy compares to traditional systematic biopsy in detecting prostate cancer among men with suspicion of prostate cancer. We found that MRI-targeted biopsy detected more high-grade cancers than systematic biopsy, and that MRI performed before biopsy can predict the risk of high-grade cancer.

Magnetic Resonance Imaging-Ultrasound Fusion Targeted Prostate Biopsy in a Consecutive Cohort of Men with No Previous Biopsy: Reduction of Over Detection through Improved Risk Stratification.

PURPOSE MRF-TB (magnetic resonance imaging-ultrasound fusion targeted prostate biopsy) may improve the detection of prostate cancer in men presenting for prostate biopsy. We report clinical outcomes of 12-core systematic biopsy and MRF-TB in men who presented for primary biopsy and further describe pathological characteristics of cancers detected by systematic biopsy and not by MRF-TB. MATERIALS AND METHODS Clinical outcomes of 452 consecutive men who underwent prebiopsy multiparametric magnetic resonance imaging followed by MRF-TB and systematic biopsy at our institution between June 2012 and June 2015 were captured in an institutional review board approved database. Clinical characteristics, biopsy results and magnetic resonance imaging suspicion scores were queried from the database. RESULTS Prostate cancer was detected in 207 of 382 men (54.2%) with a mean±SD age of 64±8.5 years and mean±SEM prostate specific antigen 6.8±0.3 ng/ml who met study inclusion criteria. The cancer detection rate of systematic biopsy and MRF-TB was 49.2% and 43.5%, respectively (p=0.006). MRF-TB detected more Gleason score 7 or greater cancers than systematic biopsy (117 of 132 or 88.6% vs 102 of 132 or 77.3%, p=0.037). Of 41 cancers detected by systematic biopsy but not by MRF-TB 34 (82.9%) demonstrated Gleason 6 disease, and 26 (63.4%) and 34 (82.9%) were clinically insignificant by Epstein criteria and a UCSF CAPRA (University of California-San Francisco-Cancer of the Prostate Risk Assessment) score of 2 or less, respectively. CONCLUSIONS In men presenting for primary prostate biopsy MRF-TB detects more high grade cancers than systematic biopsy. Most cancers detected by systematic biopsy and not by MRF-TB are at clinically low risk. Prebiopsy magnetic resonance imaging followed by MRF-TB decreases the detection of low risk cancers while significantly improving the detection and risk stratification of high grade disease.

Predictive value of negative 3T multiparametric magnetic resonance imaging of the prostate on 12-core biopsy results.

To evaluate the cancer detection rates for men undergoing 12‐core systematic prostate biopsy with negative prebiopsy multiparametric magnetic resonance imaging (mpMRI) results.

Likert score 3 prostate lesions: Association between whole-lesion ADC metrics and pathologic findings at MRI/ultrasound fusion targeted biopsy

To assess associations between whole‐lesion apparent diffusion coefficient (ADC) metrics and pathologic findings of Likert score 3 prostate lesions at MRI/ultrasound fusion targeted biopsy.

Risk Stratification by Urinary Prostate Cancer Gene 3 Testing Before Magnetic Resonance Imaging-Ultrasound Fusion-targeted Prostate Biopsy Among Men With No History of Biopsy

OBJECTIVE To determine whether a combination of prostate cancer gene 3 (PCA3) and magnetic resonance imaging (MRI) suspicion score (mSS) could further optimize detection of prostate cancer on MRI fusion-targeted biopsy (MRF-TB) among men with no history of biopsy. MATERIALS AND METHODS We included in this study 187 men presenting to our institution between June 2012 and August 2014 who underwent multiparametric MRI (mpMRI) and PCA3 before MRF-TB. Biopsy results, stratified by biopsy indication and PCA3 score, were recorded. Receiver operating characteristics curves and multivariable logistic regressions were used to model the association of PCA3 and mSS with cancer detection on MRF-TB. RESULTS PCA3 is associated with cancer detection on MRF-TB for men with no prior biopsies (area under the curve: 0.67, 95% confidence interval: 0.59-0.76). Using a cutoff of ≥35, PCA3 was associated with cancer risk among men with mSS 2-3 (P = .004), but not among those with mSS 4-5 (P = .340). The interaction of PCA3 and mSS demonstrated significantly higher discrimination for cancer than mSS alone (area under the curve: 0.83 vs 0.79, P = .0434). CONCLUSION Urinary PCA3 is associated with mSS and the detection of cancer on MRF-TB for men with no prior biopsies. PCA3 notably demonstrates a high negative predictive value among mSS 2-3. However, in the case of high-suspicion mpMRI, PCA3 is not associated with cancer detection on MRF-TB, adding little to cancer diagnosis. Further studies are needed to evaluate the utility of PCA3 in predicting cancer among men with normal mpMRI.

Using multiparametric MRI to 'personalize' biopsy for men.

Purpose of review In recent years, multiparametric magnetic resonance imaging (mpMRI) of the prostate has shown promise as a modality to identify areas of suspicion within the gland which correlate with cancer location and disease extent. However, optimal individualization of prostate biopsy using mpMRI relies on aligning the relative benefits of MRI-targeted approaches with the goals of biopsy. Recent findings For men with prior negative biopsies, mpMRI allows improved detection of occult high-grade cancers missed by repeat systematic biopsy but also has the potential to identify men who will not benefit from repeat biopsy due to a low likelihood of significant disease. For men with prior low-grade cancer diagnosis, the addition of MRI-targeted biopsy may identify those who are poor candidates for active surveillance by detecting high-risk disease without serial biopsies. For men without prior biopsy, mpMRI and targeted biopsy may help improve high-grade cancer diagnosis and significantly limit the detection of low-risk disease. Summary mpMRI of the prostate is a promising tool to address many of the shortcomings of traditional systematic prostate biopsy. Biopsy history plays a critical role in determining how to assess the potential advantages and disadvantages of prostate mpMRI in the context of each patient. Although these benefits have been suggested by published clinical outcomes data, there is a need for prospective validation of mpMRI and MRI-targeted biopsy in comparison with the current approach of systematic biopsy for all men, to define new paradigms for prostate cancer detection and risk stratification.

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.

Discriminative Ability of Commonly Used Indexes to Predict Adverse Outcomes After Radical Cystectomy: Comparison of Demographic Data, American Society of Anesthesiologists, Modified Charlson Comorbidity Index, and Modified Frailty Index.

Micro‐Abstract Given the high rate of adverse events after radical cystectomy, we evaluated the discriminative ability of commonly used comorbidity indexes and demographic factors for perioperative complications in patients undergoing radical cystectomy. We found the predictive ability of these factors to be universally poor, highlighting the need for newer models built to identify patients with a greater risk of adverse events after radical cystectomy. Background: The American Society of Anesthesiologists physical status classification system, modified Charlson Comorbidity Index (mCCI), and modified Frailty Index have been associated with complications after urologic surgery. No study has compared the predictive performance of these indexes for postoperative complications after radical cystectomy (RC) for bladder cancer. Materials and Methods: Data from 1516 patients undergoing elective RC for bladder cancer were extracted from the 2005 to 2011 American College of Surgeons National Surgical Quality Improvement Program for a retrospective review. The perioperative outcome variables assessed were occurrence of minor adverse events, severe adverse events, infectious adverse events, any adverse event, extended length of hospital stay, discharge to a higher level of care, and mortality. Patient comorbidity indexes and demographic data were assessed for their discriminative ability in predicting perioperative adverse outcomes using an area under the curve (AUC) analysis from the receiver operating characteristic curves. Results: The most predictive comorbidity index for any adverse event was the mCCI (AUC, 0.511). The demographic factors were the body mass index (BMI; AUC, 0.519) and sex (AUC, 0.519). However, the overall performance for all predictive indexes was poor for any adverse event (AUC < 0.52). Combining the most predictive demographic factor (BMI) and comorbidity index (mCCI) resulted in incremental improvements in discriminative ability compared with that for the individual outcome variables. Conclusion: For RC, easily obtained patient mCCI, BMI, and sex have overall similar discriminative abilities for perioperative adverse outcomes compared with the tabulated indexes, which are more difficult to implement in clinical practice. However, both the demographic factors and the comorbidity indexes had poor discriminative ability for adverse events.

Discordance between Ureteroscopic Biopsy and Final Pathology for Upper Tract Urothelial Carcinoma

Purpose: We evaluated the discordance between ureteroscopic biopsy and surgical pathology findings for grading and staging upper tract urothelial carcinoma. We also sought to establish preoperative predictors of aggressive tumors. Materials and Methods: We retrospectively reviewed the records of 314 patients who underwent ureteroscopic biopsy followed by surgical management of upper tract urothelial carcinoma from 2000 to 2016 at a total of 3 institutions. Our primary outcomes were muscle invasive (pT2 or greater) disease at surgical pathology and upgrading of clinical low grade tumors to pathological high grade. Results: At biopsy 61% of the patients had clinical high grade tumors and 21% had subepithelial connective tissue invasion (cT1+). On final pathology 79% of the patients had pathological high grade tumors and 45% had stage pT2 or greater. On multivariate analysis advanced patient age, clinical high grade and cT1+ were independently associated with pT2 or greater. The combined presence of clinical high grade and cT1+ had 86% positive predictive value for muscle invasion while the combined absence of clinical high grade and cT1+ had 80% negative predictive value. The likelihood of missing invasion on biopsy in patients with muscle invasive disease was increased when biopsy fragments were limited to 1 mm or less. Of clinical low grade cases on biopsy 51% were upgraded at surgery. The presence of positive urine cytology was associated with an increased risk of upgrading but this was not statistically significant. Conclusions: Clinical high grade, cT1+ on biopsy and advanced patient age are independent risk factors for muscle invasive upper tract urothelial carcinoma. There is a significant risk of upgrading in patients with clinical low grade tumors on biopsy, especially when urine cytology is positive. The predictive value of biopsy can likely be improved by more extensive ureteroscopic sampling.

The Institutional Learning Curve of Magnetic Resonance Imaging-Ultrasound Fusion Targeted Prostate Biopsy: Temporal Improvements in Cancer Detection in 4 Years

Purpose While magnetic resonance imaging‐ultrasound fusion targeted biopsy allows for improved detection of clinically significant prostate cancer, a concerning amount of clinically significant disease is still missed. We hypothesized that a number of these misses are due to the learning curve associated with magnetic resonance imaging‐ultrasound fusion targeted biopsy. We report the results of repeat magnetic resonance imaging‐ultrasound fusion targeted biopsy in men with continued suspicion for cancer and the institutional learning curve in the detection of clinically significant prostate cancer with time. Materials and Methods We analyzed the records of 1,813 prostate biopsies in a prospectively acquired cohort of men who presented for prostate biopsy in a 4‐year period. All men were offered prebiopsy magnetic resonance imaging and were assigned a maximum PI‐RADS™ (Prostate Imaging Reporting and Data System version 2) score. Biopsy outcomes in men with a suspicious region of interest were compared. The relationship between time and clinically significant prostate cancer detection was analyzed. Results The clinically significant prostate cancer detection rate increased 26% with time in men with a PI‐RADS 4/5 region of interest. On repeat magnetic resonance imaging‐ultrasound fusion targeted biopsy in men with continued suspicion for cancer 53% of those with a PI‐RADS 4/5 region of interest demonstrated clinically significant discordance from the initial magnetic resonance imaging‐ultrasound fusion targeted biopsy compared to only 23% with a PI‐RADS 1/2 region of interest. Significantly less clinically significant prostate cancer was missed or under graded in the most recent biopsies compared to the earliest biopsies. Conclusions The high upgrade rate on repeat magnetic resonance imaging‐ultrasound fusion targeted biopsy and the increasing cancer detection rate with time show the significant learning curve associated with magnetic resonance imaging‐ultrasound fusion targeted biopsy. Men with low risk or negative biopsies with a persistent, concerning region of interest should be promptly rebiopsied. Improved targeting accuracy with operator experience can help decrease the number of missed cases of clinically significant prostate cancer.