Multiparametric Magnetic Resonance Imaging Fusion Research Articles

MRI and RNA-seq fusion for prediction of pathological response to neoadjuvant chemotherapy in breast cancer

Accurate prediction of the pathological complete response (pCR) to neoadjuvant chemotherapy (NAC) is crucial for precise treatment of breast cancer. However, current studies mainly rely on single-modal data, with limited studies focusing on multimodal data. In this study, we developed and validated a deep learning-based multimodal fusion model that predicts the response of breast tumor to NAC by integrating multi-parametric magnetic resonance imaging (MRI) and RNA sequencing (RNA-seq) information related to breast tumor. For comparison, we separately built four single-modal models with either MR images or RNA-seq data. Moreover, our approach has demonstrated better performance in integrating MR images and RNA-seq data. The average accuracy is 90.20% and area under the receiver operating characteristic curve (AUC) is 0.936 for our model. These findings indicate that our proposed approach has achieved higher accuracy in predicting the pathological response to NAC.

Attention mechanism based multi-sequence MRI fusion improves prediction of response to neoadjuvant chemoradiotherapy in locally advanced rectal cancer

BackgroundAccurate prediction of response to neoadjuvant chemoradiotherapy (nCRT) is very important for treatment plan decision in locally advanced rectal cancer (LARC). The aim of this study was to investigate whether self-attention mechanism based multi-sequence fusion strategy applied to multiparametric magnetic resonance imaging (MRI) based deep learning or hand-crafted radiomics model construction can improve prediction of response to nCRT in LARC.MethodsThis retrospective analysis enrolled 422 consecutive patients with LARC who received nCRT before surgery at two hospitals. All patients underwent multiparametric MRI scans with three imaging sequences. Tumor regression grade (TRG) was used to assess the response of nCRT based on the resected specimen. Patients were separated into 2 groups: poor responders (TRG 2, 3) versus good responders (TRG 0, 1). A self-attention mechanism, namely channel attention, was applied to fuse the three sequence information for deep learning and radiomics models construction. For comparison, other two models without channel attention were also constructed. All models were developed in the same hospital and validated in the other hospital.ResultsThe deep learning model with channel attention mechanism achieved area under the curves (AUCs) of 0.898 in the internal validation cohort and 0.873 in the external validation cohort, which was the best performed model in all cohorts. More importantly, both the deep learning and radiomics model that applied channel attention mechanism performed better than those without channel attention mechanism.ConclusionsThe self-attention mechanism based multi-sequence fusion strategy can improve prediction of response to nCRT in LARC.

Peritumoral Radiomics for Identification of Telomerase Reverse Transcriptase Promoter Mutation in Patients With Glioblastoma Based on Preoperative MRI.

Purpose: To evaluate the value of intra- and peritumoral deep learning (DL) features based on multi-parametric magnetic resonance imaging (MRI) for identifying telomerase reverse transcriptase (TERT) promoter mutation in glioblastoma (GBM). Methods: In this study, we included 229 patients with GBM who underwent preoperative MRI in two hospitals between November 2016 and September 2022. We used four 2D Convolutional Neural Networks (GoogLeNet, DenseNet121, VGG16, and MobileNetV3-Large) to extract intra- and peritumoral DL features. The Mann-Whitney U test, Pearson correlation analysis, least absolute shrinkage and selection operator, and logistic regression analysis were used for feature selection and construction of DL radiomics (DLR) signatures in different regions. These multi-parametric and multi-region signatures were combined to identify TERT promoter mutation. The area under the receiver operating characteristic curve (AUC) was used to evaluate the effects of the signatures. Results: The signatures based on the DL features from the peritumoral regions with expansion distances of 2mm, 8mm, and 10mm using the GoogLeNet architecture correlated with the optimal AUC values (test set: .823, .753, and .768) in the T2-weighted, T1-weighted contrast-enhanced, and T1-weighted images. Using the stacking fusion method, DLR with multi-parameter and multi-region fusion achieved the best discrimination with AUC values of .948 and .902 in the training and test sets, respectively. Conclusions: The radiomics model based on the fusion of multi-parameter MRI intra- and peritumoral DLR signatures may help to identify TERT promoter mutation in patients with GBM.

Multi-parametric Magnetic Resonance Imaging Fusion for Automatic Classification of Prostate Cancer.

Computer-aided diagnosis (CAD) of prostate cancer (PCa) using multi-parametric magnetic resonance imaging (mp-MRI) has recently gained great research interest. In this work, a fully automatic CAD pipeline of PCa using mp-MRI data is presented. In order to fully explore the mp-MRI data, we systematically investigate three multi-modal medical image fusion strategies in convolutional neural networks, namely input-level fusion, feature-level fusion, and decision-level fusion. Extensive experiments are conducted on two datasets with different PCa-related diagnostic tasks. We identify a pipeline that works relatively the best for both diagnostic tasks, two important components of which are stacking three adjacent slices as the input and performing decision-level fusion with specific loss weights. Clinical relevance- This work provides a practical method for automated diagnosis of PCa based on multi-parametric MRI.

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.

Transperineal versus transrectal multi-parametric magnetic resonance imaging fusion targeted prostate biopsy.

Objectives:To compare transperineal biopsies (TPBx) with transrectal ultrasound-guided biopsy (TRUSBx) in order to provide evidence, making clinicians able to select the appropriate biopsy approach under different conditions.Methods:A comparative prospective study, conducted in King Khalid University Hospital (KKUH) and King Faisal Specialist Hospital and Research Centre (KFSH&RC), Riyadh, Kingdom of Saudi Arabia, between March 2019 and February 2020. All patients with raised prostate-specific antigen or atypical digital rectal examination findings were subjected to multi-parametric magnetic resonance imaging (MRI). Those with positive findings were referred to targeted fusion- guided biopsy either TPBx or TRUSBx, randomly. Complication rate, cancer detection rate, and procedure time were recorded.Results:Transperineal biopsies and TRUSBx had an equivalent complication rate. However, both case detection rate and clinically significant cancer detection rate were significantly higher in TPBx versus TRUSBx (45.1% versus 29.1%, p=0.003; and 71.8% versus 43.7%, p=0.002; respectively). Transperineal biopsies was a longer procedure than TRUSBx (41.2±0.7 min versus 13±2.3 min, p=0.0001).Conclusion:No difference in complication rate was detected between the 2 procedures; however, TPBx was more effective for cancer detection in general and clinically significant cancer detection in particular.

Prostate Cancer Detection Using 3-D Shear Wave Elasticity Imaging

Transrectal ultrasound (TRUS) B-mode imaging provides insufficient sensitivity and specificity for prostate cancer (PCa) targeting when used for biopsy guidance. Shear wave elasticity imaging (SWEI) is an elasticity imaging technique that has been commercially implemented and is sensitive and specific for PCa. We have developed a SWEI system capable of 3-D data acquisition using a dense acoustic radiation force (ARF) push approach that leads to enhanced shear wave signal-to-noise ratio compared with that of the commercially available SWEI systems and facilitates screening of the entire gland before biopsy. Additionally, we imaged and assessed 36 patients undergoing radical prostatectomy using 3-D SWEI and determined a shear wave speed threshold separating PCa from healthy prostate tissue with sensitivities and specificities akin to those for multiparametric magnetic resonance imaging fusion biopsy. The approach measured the mean shear wave speed in each prostate region to be 4.8 m/s (Young's modulus E = 69.1 kPa) in the peripheral zone, 5.3 m/s (E = 84.3 kPa) in the central gland and 6.0 m/s (E = 108.0 kPa) for PCa with statistically significant (p < 0.0001) differences among all regions. Three-dimensional SWEI receiver operating characteristic analyses identified a threshold of 5.6 m/s (E = 94.1 kPa) to separate PCa from healthy tissue with a sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and area under the curve (AUC) of 81%, 82%, 69%, 89% and 0.84, respectively. Additionally, a shear wave speed ratio was assessed to normalize for tissue compression and patient variability, which yielded a threshold of 1.11 to separate PCa from healthy prostate tissue and was accompanied by a substantial increase in specificity, PPV and AUC, where the sensitivity, specificity, PPV, NPV and AUC were 75%, 90%, 79%, 88% and 0.90, respectively. This work illustrates the feasibility of using 3-D SWEI data to detect and localize PCa and demonstrates the benefits of normalizing for applied compression during data acquisition for use in biopsy targeting studies.

Pain in Men Undergoing Transperineal Free-Hand Multiparametric Magnetic Resonance Imaging Fusion Targeted Biopsies under Local Anesthesia: Outcomes and Predictors from a Multicenter Study of 1,008 Patients.

Several transperineal biopsy series have proven feasibility under local anesthesia. However, there is a lack of large analyses detailing pain outcomes and factors influencing pain. From 2016 to 2019 we performed a multicenter prospective study in men undergoing multiparametric magnetic resonance imaging-transperineal fusion biopsies (target+systematic cores) under local anesthesia. Primary outcomes were 1) pain scores (assessed through a 0 to 10-point numeric rating scale) and 2) identification of factors associated with severe pain. The secondary outcome was to evaluate pain influence on clinically significant prostate cancer target cores detection. We included 1,008 men undergoing transperineal fusion biopsies under local anesthesia. Mean±SD numeric rating scale pain scores were 3.9±2.1 at local anesthesia administration and 3.1±2.3 when performing biopsies. Pain was not associated with lower clinically significant prostate cancer detection on targeted cores (p=0.23 and p=0.47 depending on clinically significant prostate cancer definition). On multivariate analysis age (OR 0.96, 95% CI 0.94-0.99) and severe anxiety (OR 2.99, 95% CI 1.83-4.89) were a protective and risk factor, respectively, for severe biopsy pain. Procedural time was also associated with an increased risk of experiencing severe biopsy pain (OR 1.04, 95% CI 1.00-1.08). If aiming to test the possible effects of anxiety preventive measures on pain, an anxiety cutoff greater than 6 on a numeric rating scale would decrease to 13% the number of patients being treated while identifying 56% of those experiencing severe pain. Transperineal fusion biopsies under local anesthesia result in moderate pain. Pain does not influence clinically significant prostate cancer target detection. Patient anxiety predicts pain. A numeric rating scale based anxiety assessment may be used to identify those at higher risk for experiencing severe pain in men undergoing transperineal fusion biopsies.

Prostate Mapping for Cancer Diagnosis: The Madrid Protocol. Transperineal Prostate Biopsies Using Multiparametric Magnetic Resonance Imaging Fusion and Micro-Ultrasound Guided Biopsies.

We assessed the prostate cancer detection accuracy of transperineal prostate biopsy using multiparametric magnetic resonance imaging/ultrasound fusion targeted biopsy and micro-ultrasound during the same procedure. Micro-ultrasound is a new high-resolution imaging system that allows real-time targeted biopsy. A total of 194 consecutive patients underwent transperineal prostate biopsies using real-time targeted micro-ultrasound (ExactVu™) and ultrasound fusion targeted biopsy (BiopSee®) in the same procedure, from February 2018 to September 2019. Biopsies were performed using a transperineal needle guide attached to the 29 MHz high-resolution micro-ultrasound transducer. The overall positive rate was 56% (108) for prostate cancer and 42% (81) for clinically significant prostate cancer (Gleason Grade Group greater than 1), and adding micro-ultrasound and magnetic resonance imaging detected significantly more clinically significant prostate cancer than systematic biopsy (p <0.001). Micro-ultrasound found 12 of 108 (11%) prostate cancers that were missed by all other techniques and 11 (92%) were clinically significant prostate cancer. PI-RADS® and PRI-MUS™ (Prostate Risk Identification Using Micro-Ultrasound) were strong predictors of clinically significant prostate cancer in a logistic regression model (AUC 0.76). For prostate specific antigen greater than 4 ng/ml, PI-RADS greater than 3, there was an improvement in detection rate between PRI-MUS 4 and PRI-MUS 5 (52% Gleason Grade Group greater than 1 to 92% Gleason Grade Group greater than 1). No fever or clinical infection was observed and 17 (8.7%) patients presented with minor complications (Clavien Dindo I). This is the first study using a transperineal approach for micro-ultrasound guided biopsy and multiparametric magnetic resonance imaging fusion biopsy. The results show a high accuracy for prostate cancer and clinically significant prostate cancer diagnosis, without infectious complications. The proposed method should be validated in large randomized clinical trials.

Use of a trizonal schema to assess targeting accuracy in prostatic fusion biopsy.

To describe the use of a novel 'trizonal' biopsy schema in which 'near-target' biopsies are taken adjacent to the MRI lesion, in addition to target and systematic biopsies, to determine the accuracy of prostate MRI fusion systems. A trizonal biopsy technique was used to evaluate 75 men with small Prostate Imaging Reporting and Data System (PI-RADS) 3-5 MRI lesions (<15mm) identified from a prospective cohort of 290 men undergoing multiparametric magnetic resonance imaging (MRI) for suspected prostate cancer at a single high-volume institution between September 2017 and May 2019. In addition to target and systematic biopsies, near-target biopsies were taken 4mm from the apparent border of the MRI lesion. Comparisons were made between highest International Society of Urological Pathology grade and longest tumour length. Fifty-three men with significant prostate cancer in the same quadrant as the target were included in the final analysis. The percentages of positive cores from target, near-target and MRI-negative zones were 66%, 39% and 17%, respectively. Significant cancer was detected in the near-target zone in 77% of cases when the target zone was positive. A total of 17% of participants were upgraded by a median (range) of 1 (1-3) grades through the addition of near-target cores. Notably, 9% of men were diagnosed with clinically significant prostate cancer solely via the near-target biopsy cores when the target cores were negative. The use of near-target biopsies as part of a trizonal biopsy schema provides a novel methodology to optimize clinically significant prostate cancer detection.

Serial Comparison of Cancer Detection Rate Between Transrectal Ultrasound Sonography Guided Biopsy and Magnetic Resonance Imaging for Repeat Biopsy by a Propensity Score Matching Cohort: A Single Center Experience

Purpose To compare biopsy performance of 2 approaches for multiparametric magnetic resonance imaging (MRI) guided biopsy and transrectal ultrasonography (TRUS)-guided biopsy with 2nd and 3rd repeat biopsy patients in prostate cancer detection. Materials and Methods This retrospective study reviewed 2,868 patients who was performed prostate biopsy between September 2013 to March 2017 at Samsung Medical Center, Seoul, Korea with TRUS-guided random biopsy and MRI fusion, MRI cognitive, and MRI-guided biopsy as 2nd and 3rd repeat biopsy and propensity matching was applied to reduce bias. Detection rate of each study was compared with 1:1 matching. Results Among 265 patients who performed TRUS 2nd biopsy, positivity rate for prostate cancer (PCa) was 18.49% (n=49/265) while 54.72% (n=145/265) for MRI-guided biopsy. In 3rd biopsy, positivity rate for PCa of TRUS biopsy was 17.74% (n=11/62) while 56.45% (n=35/62) for MRI guided biopsy. There was no significant difference in the detection rate for the patient with Gleason score 8 or more. Conclusions MRI-guided biopsy was associated with a higher detection rate of prostate cancer with especially in patients with prior negative biopsy. Key Words: Prostatic neoplasm; Repeat biopsy; Magnetic resonance imaging; Transrectal ultrasonography; Outcome.

A 17-Gene Genomic Prostate Score Assay Provides Independent Information on Adverse Pathology in the Setting of Combined Multiparametric Magnetic Resonance Imaging Fusion Targeted and Systematic Prostate Biopsy

Multiparametric magnetic resonance imaging and biopsy based molecular tests such as the 17-gene Oncotype DX® Genomic Prostate Score™ assay are increasingly performed to improve risk stratification in men with clinically localized prostate cancer. The prostate score assay was previously shown to be a significant independent predictor of adverse pathology findings at radical prostatectomy in men diagnosed by systematic biopsies only. Therefore, we investigated the ability of the prostate score assay to predict adverse pathology findings in the setting of magnetic resonance imaging guided prostate biopsy. We identified men diagnosed with NCCN® (National Comprehensive Cancer Network®) very low, low or intermediate risk prostate cancer who underwent simultaneous multiparametric magnetic resonance imaging fusion targeted and systematic prostate biopsy with subsequent radical prostatectomy within 6 months. Prostate score assay testing was performed on biopsy tissue with the highest Gleason score. The primary outcome of the study was adverse pathology findings, defined as Gleason score 4 + 3 or greater disease and/or pT3+ at radical prostatectomy. Independent predictors of adverse pathology findings were determined in a multivariable model to adjust for clinical parameters. A total of 134 men were eligible for primary analysis. On univariable analysis the UCLA score, magnetic resonance imaging, prostate score assay results and biopsy Gleason score were significant predictors of adverse pathology findings. After multivariable adjustment prostate score assay values remained a significant predictor of adverse pathology results (prostate score assay per 20 U OR 3.28, 95% CI 1.74-6.62, p <0.001). A wide and overlapping distribution of prostate score assay results was seen across PI-RADS® (Prostate Imaging Reporting and Data System) version 2 scores. The prostate score assay result is an independent predictor of adverse pathology findings in patients who were diagnosed with very low, low or intermediate risk prostate cancer in the setting of multiparametric magnetic resonance imaging fusion prostate biopsy. This assay can be useful as an independent technology or an adjunct technology to multiparametric magnetic resonance imaging to individualize risk stratification of low and intermediate risk prostate cancer.

Diagnostic Accuracy of Multiparametric Magnetic Resonance Imaging and Fusion Guided Targeted Biopsy Evaluated by Transperineal Template Saturation Prostate Biopsy for the Detection and Characterization of Prostate Cancer

We evaluated the diagnostic accuracy of multiparametric magnetic resonance imaging and multiparametric magnetic resonance imaging/transrectal ultrasound fusion guided targeted biopsy against that of transperineal template saturation prostate biopsy to detect prostate cancer. We retrospectively analyzed the records of 415 men who consecutively presented for prostate biopsy between November 2014 and September 2016 at our tertiary care center. Multiparametric magnetic resonance imaging was performed using a 3 Tesla device without an endorectal coil, followed by transperineal template saturation prostate biopsy with the BiopSee® fusion system. Additional fusion guided targeted biopsy was done in men with a suspicious lesion on multiparametric magnetic resonance imaging, defined as Likert score 3 to 5. Any Gleason pattern 4 or greater was defined as clinically significant prostate cancer. The detection rates of multiparametric magnetic resonance imaging and fusion guided targeted biopsy were compared with the detection rate of transperineal template saturation prostate biopsy using the McNemar test. We obtained a median of 40 (range 30 to 55) and 3 (range 2 to 4) transperineal template saturation prostate biopsy and fusion guided targeted biopsy cores, respectively. Of the 124 patients (29.9%) without a suspicious lesion on multiparametric magnetic resonance imaging 32 (25.8%) were found to have clinically significant prostate cancer on transperineal template saturation prostate biopsy. Of the 291 patients (70.1%) with a Likert score of 3 to 5 clinically significant prostate cancer was detected in 129 (44.3%) by multiparametric magnetic resonance imaging fusion guided targeted biopsy, in 176 (60.5%) by transperineal template saturation prostate biopsy and in 187 (64.3%) by the combined approach. Overall 58 cases (19.9%) of clinically significant prostate cancer would have been missed if fusion guided targeted biopsy had been performed exclusively. The sensitivity of multiparametric magnetic resonance imaging and fusion guided targeted biopsy for clinically significant prostate cancer was 84.6% and 56.7% with a negative likelihood ratio of 0.35 and 0.46, respectively. Multiparametric magnetic resonance imaging alone should not be performed as a triage test due to a substantial number of false-negative cases with clinically significant prostate cancer. Systematic biopsy outperformed fusion guided targeted biopsy. Therefore, it will remain crucial in the diagnostic pathway of prostate cancer.

Multiparametric Magnetic Resonance Imaging (MRI) and MRI–Transrectal Ultrasound Fusion Biopsy for Index Tumor Detection: Correlation with Radical Prostatectomy Specimen

BackgroundMultiparametric magnetic resonance imaging (mpMRI) and MRI fusion targeted biopsy (FTB) detect significant prostate cancer (sPCa) more accurately than conventional biopsies alone. ObjectiveTo evaluate the detection accuracy of mpMRI and FTB on radical prostatectomy (RP) specimen. Design, setting and participantsFrom a cohort of 755 men who underwent transperineal MRI and transrectal ultrasound fusion biopsy under general anesthesia between 2012 and 2014, we retrospectively analyzed 120 consecutive patients who had subsequent RP. All received saturation biopsy (SB) in addition to FTB of lesions with Prostate Imaging Reporting and Data System (PI-RADS) score ≥2. Outcome measurements and statistical analysisThe index lesion was defined as the lesion with extraprostatic extension, the highest Gleason score (GS), or the largest tumor volume (TV) if GS were the same, in order of priority. GS 3+3 and TV ≥1.3ml or GS ≥3+4 and TV ≥0.55ml were considered sPCa. We assessed the detection accuracy by mpMRI and different biopsy approaches and analyzed lesion agreement between mpMRI and RP specimen. Results and limitationsOverall, 120 index and 71 nonindex lesions were detected. Overall, 107 (89%) index and 51 (72%) nonindex lesions harbored sPCa. MpMRI detected 110 of 120 (92%) index lesions, FTB (two cores per lesion) alone diagnosed 96 of 120 (80%) index lesions, and SB alone diagnosed 110 of 120 (92%) index lesions. Combined SB and FTB detected 115 of 120 (96%) index foci. FTB performed significantly less accurately compared with mpMRI (p=0.02) and the combination for index lesion detection (p=0.002). Combined FTB and SB detected 97% of all sPCa lesions and was superior to mpMRI (85%), FTB (79%), and SB (88%) alone (p<0.001 each). Spearman's rank correlation coefficient for index lesion agreement between mpMRI and RP was 0.87 (p<0.001). Limitations included the retrospective design, multiple operators, and nonblinding of radiologists. ConclusionsMpMRI identified 92% of index lesions compared with RP histopathology. The combination of FTB and SB was superior to both approaches alone, reliably detecting 97% of sPCa lesions. Patient summaryMultiparametric magnetic resonance imaging detects the index lesion accurately in 9 of 10 patients; however, the combined biopsy approach, while missing less significant cancer, comes at the cost of detecting more insignificant cancer.

Multiparametric Magnetic Resonance Imaging Enhances Detection of Significant Tumor in Patients on Active Surveillance for Prostate Cancer

To determine whether multiparametric magnetic resonance imaging (MRI) of the prostate (mpMRI) combined with MRI fusion technology during transrectal ultrasound-guided biopsy can enhance the detection of significant disease in patients with apparent low-risk prostate cancer on active surveillance (AS). We reviewed the charts of 603 patients on AS for localized prostate cancer between January 2006 and September 2013. mpMRI before repeat transrectal ultrasound-guided biopsy was obtained in 111 patients, of whom 69 underwent subsequent fusion biopsy (39 true and 30 cognitive) in addition to standard template biopsy. The results of fusion biopsy were compared with the standard biopsy. The primary endpoint was termination of AS. mpMRI detected 118 suspicious lesions in 70 patients (63%). Of these, 42 patients (60%) had lesions with Prostate imaging, reporting, and data system (PIRADS) score 3, and 28 patients (40%) had PIRADS score 4 or 5 lesions. AS was terminated in 27 (24.3%) of the 111 patients who underwent mpMRI. Seventeen patients stopped AS based on mpMRI findings including 16 for pathologic progression in target biopsies and 1 for lesion size increase, whereas the other 10 stopped AS because of pathologic progression in the standard cores (n = 6) or other reasons (n = 4). Use of mpMRI increased the rate of AS termination (27 vs. 10; P = .002). On multivariate analysis, PIRADS score 4-5 (vs. 3) was the only significant predictor of AS termination (P = .015). These preliminary retrospective findings suggest that mpMRI with subsequent fusion biopsy enhances the identification of AS patients requiring definitive treatment.

Editorial Comment

Multiparametric magnetic resonance imaging (mpMRI) and fusion-guided biopsy have ushered in a new era in the diagnosis and treatment of prostate cancer. As its current role continues to expand, defining its value among various patient populations has become a primary focus. The present study 1 Abdi H. Pourmalek F. Zargar H. et al. Multiparametric magnetic resonance imaging enhances detection of significant tumor in patients on active surveillance for prostate cancer. Urology. 2015; 85: 423-429 Abstract Full Text Full Text PDF PubMed Scopus (41) Google Scholar adds to the growing body of literature supporting the use of imaging in active surveillance (AS) and its direct impact on patient management. Using a heterogeneous AS population, the authors 1 Abdi H. Pourmalek F. Zargar H. et al. Multiparametric magnetic resonance imaging enhances detection of significant tumor in patients on active surveillance for prostate cancer. Urology. 2015; 85: 423-429 Abstract Full Text Full Text PDF PubMed Scopus (41) Google Scholar used a clinically relevant endpoint—the termination of AS—to gauge the impact of mpMRI on treatment decision making. Of 111 patients undergoing mpMRI, 24.3% subsequently sought active treatment, of which 63% were based on imaging findings alone. An important endpoint is also pathologic progression. The subgroup analysis of 97 patients with an initial Gleason score of ≤6 demonstrated progression to a Gleason score ≥7 in 30.6% of patients. This echoes recent findings of the University of Toronto group revealing progression in 26% of patients and established a negative predictive value of 100% for mpMRI in ruling out a Gleason score ≥7 disease. 2 Da Rosa M.R. Milot L. Sugar L. et al. A prospective comparison of MRI-US fused targeted biopsy versus systematic ultrasound-guided biopsy for detecting clinically significant prostate cancer in patients on active surveillance. J Magn Reson Imaging. 2015; 41: 220-225 Crossref PubMed Scopus (78) Google Scholar Multiparametric Magnetic Resonance Imaging Enhances Detection of Significant Tumor in Patients on Active Surveillance for Prostate CancerUrologyVol. 85Issue 2PreviewTo determine whether multiparametric magnetic resonance imaging (MRI) of the prostate (mpMRI) combined with MRI fusion technology during transrectal ultrasound-guided biopsy can enhance the detection of significant disease in patients with apparent low-risk prostate cancer on active surveillance (AS). Full-Text PDF ReplyUrologyVol. 85Issue 2PreviewWe share in the growing enthusiasm for multiparametric magnetic resonance imaging (mpMRI) in the management of patients on active surveillance but recognize also that there are still many obstacles in demonstrating its clinical utility. Ideally, studies like our own will be validated in prospective trials, and the holy grail of mpMRI is to demonstrate that a simple scan can replace biopsies in men on active surveillance. Because the most relevant clinical endpoints (metastasis-free and overall survival) require >10 years to reach, it will be challenging to address this clinical need. Full-Text PDF