Objectives
The aim of the current report is to provide an update in the imaging interpretation of prostate cancer on multiparametric magnetic resonance imaging (mpMRI), with a special focus on how to ...discriminate pathological tissue from the most common pitfalls that may be encountered during daily clinical practice using the Prostate Imaging Reporting and Data System (PI-RADS) version 2 guidelines.
Methods
All the cases that are shown in this pictorial review comply with the European Society of Urogenital Radiology (ESUR) guidelines for technical mpMRI requirements.
Results
Despite the standardised manner to report mpMRI (PI-RADS v. 2), some para-physiologic appearances of the prostate can mimic cancer. As such, it is crucial to be aware of these pitfalls, in order to avoid the under/overestimation of prostate cancer.
Conclusions
A detailed knowledge of normal and abnormal findings in mpMRI of the prostate is pivotal for an accurate management of the wide spectrum of clinical scenarios that radiologists may encounter during their daily practice.
Teaching Points
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Some para-physiologic appearances of the prostate may mimic cancer.
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Knowledge of normal and abnormal findings in prostate mpMRI is pivotal.
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Any radiologist involved in prostate mpMRI reporting should be aware of pitfalls.
Purpose In men with suspicion of prostate cancer the standard of cancer detection is transrectal ultrasound guided 10 to 12-core systematic biopsy. The targeted biopsy only strategy using magnetic ...resonance imaging-transrectal ultrasound image registration is gaining in popularity. We assessed the noninferiority of targeted vs systematic biopsy. Materials and Methods Between June and October 2014 a total of 108 biopsy naïve patients with prostate specific antigen between 4 and 20 ng/ml, normal rectal examination and a single suspicious image on magnetic resonance imaging were included in study at 7 centers. Patients underwent systematic biopsy by a first operator blinded to magnetic resonance imaging, immediately followed by 3 targeted biopsies within the suspicious image by a second operator. The primary end point was the cancer detection rate. The noninferiority margin was set at −5%. The secondary end points were the detection rate of clinically significant prostate cancer (maximum cancer core length 5 mm or greater for Gleason 6 or any Gleason 7 or greater disease) and procedure duration. Results Systematic and targeted biopsies detected cancer in 66 (61.1%) and 61 patients (56.5%), respectively. The mean difference was −4.5% with a 95% CI lower bound of −11.8%. A total of 13 patients with protocol violations were excluded from the per protocol analysis, which showed a mean difference of −5.2% with a 95% CI lower bound of −13.1%. Clinically significant prostate cancer was detected in 50 (46.2%) and 52 patients (48.1%) with systematic and targeted biopsies, respectively (p = 0.69). The mean ± SD duration of image fusion plus targeted biopsy was 16.7 ± 7 minutes vs 7.4 ± 3 for systematic biopsy (p <0.001). Conclusions Targeted biopsy seemed to be inferior to systematic biopsy for overall cancer detection. Detection of clinically significant prostate cancer did not differ between targeted and systematic biopsies.
This article is a primer on the technical aspects of performing a high-quality dynamic contrast-enhanced MRI (DCE-MRI) examination of the prostate gland.
DCE-MRI is emerging as a useful clinical ...technique as part of a multi-parametric approach for evaluating the extent of primary and recurrent prostate cancer. Performing a high-quality DCE-MRI examination requires a good understanding of the technical aspects and limitations of image acquisition and postprocessing techniques.
•The mean ADC (ADCmean) of Gleason score (GS) 3 + 3 transitional zone prostate cancer (TZ-PCa) is lower than that of peripheral zone prostate cancer (PZ-PCa).•ADCmean of GS 3 + 3 TZ-PCa is similar to ...that of high-grade PCa of any zone.•In patients with GS 3 + 3 PCa, TZ-PCa shows higher glandular density than PZ-PCa.•Poor correlation exists between glandular density (ADCmean) and glandular differentiation (GS).
To compare the mean apparent diffusion coefficient (ADCmean) and glandular density of Gleason score (GS) 3 + 3 transition zone prostate cancers (TZ-PCa) with those of the peripheral zone (PZ-PCa).
Seventy-nine men (mean age: 65 ± 6 SD years; range: 52–81 years) with 37 TZ-PCa (37/79; 53 %) and 42 PZ-PCa (42/79; 47 %) had prostate MRI before radical prostatectomy. Glandular cell density was semi-quantitatively evaluated in all tumors. ADCmean and glandular cell density of GS3 + 3 TZ-PCa were compared to those of PZ-PCa. ADCmean was correlated to GS in each zone.
ADCmean of GS 3 + 3 tumors was significantly lower in the TZ (728 × 10−6±52 SD mm²/s; range: 670−1060mm²/s) than in the PZ (865 × 10−6 ±121 SD mm²/s; range: 670−1120mm²/s) (p = 0.0007), related to a significantly higher glandular density involving more than 50 % of the tumor in 58 % (7/12) of patients in GS3 + 3 TZ-PCa versus 7.6 % (1/13) in PZ-PCa (p = 0.03). ADCmean of GS3 + 3 TZ-PCa was not significantly different from that of GS 3 + 4 (p = 0.14) or GS>3 + 4 Ca (p = 0.9), whatever the zone of origin. In the PZ, ADCmean of GS 3 + 3-PCa was higher than that of Gleason>3 + 4 PZ-PCa (p = 0.02) and similar to that of GS 3 + 4 PZ-PCa (p = 0.24). Correlation between ADCmean and GS was weak for TZ-PCa (ρ = 0.32; p = 0.04) and moderate for PZ-PCa (ρ = 0.45; p = 0.003).
ADCmean of GS 3 + 3 TZ-PCa is significantly lower than that of GS 3 + 3 PZ-PCa, related to a unique dense histological pattern and reaches that of higher-grade PCa, whatever the zone of origin.
Purpose We evaluated the accuracy of prostate magnetic resonance imaging- transrectal ultrasound targeted biopsy for Gleason score determination. Materials and Methods We selected 125 consecutive ...patients treated with radical prostatectomy for a clinically localized prostate cancer diagnosed on magnetic resonance imaging-transrectal ultrasound targeted biopsy and/or systematic biopsy. On multiparametric magnetic resonance imaging each suspicious area was graded according to PI-RADS™ score. A correlation analysis between multiparametric magnetic resonance imaging and pathological findings was performed. Factors associated with determining the accuracy of Gleason score on targeted biopsy were statistically assessed. Results Pathological analysis of radical prostatectomy specimens detected 230 tumor foci. Multiparametric magnetic resonance imaging detected 151 suspicious areas. Of these areas targeted biopsy showed 126 cancer foci in 115 patients, and detected the index lesion in all of them. The primary Gleason grade, secondary Gleason grade and Gleason score of the 126 individual tumors were determined accurately in 114 (90%), 75 (59%) and 85 (67%) cases, respectively. Maximal Gleason score was determined accurately in 80 (70%) patients. Gleason score determination accuracy on targeted biopsy was significantly higher for low Gleason and high PI-RADS score tumors. Conclusions Magnetic resonance imaging-transrectal ultrasound targeted biopsy allowed for an accurate estimation of Gleason score in more than two-thirds of patients. Gleason score misclassification was mostly due to a lack of accuracy in the determination of the secondary Gleason grade.
To compare the diagnostic performance of the magnetic resonance (MR) imaging-based Prostate Imaging Reporting and Data System (PI-RADS) and a Likert scale in the detection of prostate cancer in a ...cohort of patients undergoing initial prostate biopsy.
This institutional review board-approved two-center prospective study included 118 patients with normal digital rectal examination (DRE) results but elevated prostate-specific antigen (PSA) levels (4-20 ng/mL) who were referred for initial prostate biopsies and had one suspicious (Likert scale score, ≥3) focus at prebiopsy 1.5-T multiparametric MR imaging performed with T2-weighted, diffusion-weighted DW, and dynamic contrast material-enhanced imaging. Targeted core biopsies and random systematic core biopsies were performed. The elementary unit for analysis was the core. Relationships were assessed by using the Mann-Whitney U test. Yates corrected and Pearson χ(2) tests were used to evaluate categoric variables. A training set was randomly drawn to construct the receiver operating characteristic curves for the summed PI-RADS scores and for the Likert scale scores. The thresholds to recommend biopsy were obtained from the Youden J statistics and were tested in the remaining validation set in terms of predictive characteristics. Interobserver variability was analyzed by using weighed κ statistics in a random set of 50 patients.
Higher T2-weighted, DW, and dynamic contrast-enhanced imaging PI-RADS scores were observed in areas that yielded cancer-positive cores. The percentage of positive cores increased with the sum of scores aggregated in five classes as follows: For summed PI-RADS scores of 3-5, the percentage of positive cores was 2.3%; for scores of 6-8, it was 5.8%; for scores of 9 or 10, it was 24.7%; for scores of 11 or 12, it was 51.8%; and for scores of 13-15, it was 72.1% (P for trend, <.0001). For the threshold of summed PI-RADS scores of 9 or greater, sensitivity was 86.6%, specificity was 82.4%, the positive predictive value was 52.4%, the negative predictive value was 96.5%, and accuracy was 83.2%. The respective data for Likert scale scores of 3 or greater were 93.8%, 73.6%, 44.3%, 98.1%, and 73.3%. Good interobserver agreement was observed for the Likert scale (κ = 0.80) and the summed PI-RADS (κ = 0.73) scoring systems.
PI-RADS provided the site-specific stratified risk of cancer-positive cores in biopsy-naive men with normal DRE results and elevated PSA levels. There was no significant difference between summed PI-RADS scores of 9 or greater and Likert scale scores of 3 or greater in the detection of cancer in the peripheral zone.
Objectives
To evaluate the diagnostic accuracy (Acc) of full-field optical coherence tomography (FFOCT) for cancer detection on prostate biopsy.
Materials and methods
Thirty-eight consecutive ...patients with elevated PSA and/or suspicious digital rectal examination were prospectively included. For each patient, 1–10 cores were randomly selected and imaged with FFOCT immediately after sampling. The images obtained were de-identified and analyzed by three pathologists blinded to the results of pathological evaluation. The overall average Acc was measured, as well as sensitivity (Se), specificity (Sp), positive and negative predictive values (PPV and NPV). The Acc learning curve was assessed by multivariate logistic regression, and inter-reader concordance was assessed by Kappa index.
Results
One hundred and nineteen cores were imaged. Of them, 40 (33.6 %) were involved with cancer. The overall average Acc of FFOCT for cancer detection was of 70.6 %. Se, Sp, PPV, and NPV were of 63, 74, 55.5, and 80 %, respectively. A substantial agreement was observed among pathologists (
κ
= 0.6,
p
< 0.001). On multivariate analysis, Acc was associated with the number of previously interpreted cases, with a predicted Acc of 82 % at the end of learning curve. The overall average accuracy for high Gleason score (>3 + 3) determination was of 72 %, although results were limited by the small amount of cases.
Conclusions
FFOCT of prostate biopsy cores may provide a diagnostic accuracy greater than 80 %, with a good reliability and a high NPV.
Take home message
“Full-field optical coherence tomography is a novel imaging modality that could have a potential value in real-time diagnosis of prostate cancer during prostate biopsy procedures.”
To show how multiparametric MRI can rule in the presence of significant prostate cancer (PCa), allowing for magnetic resonance-targeted biopsies to detect aggressive tumors eligible for immediate ...treatment and to evaluate if mp-MRI can rule out significant tumor foci to avoid overdiagnosis and overtreatment of PCa.
Diffusion-weighted MRI plays a major role to detect tumor foci and to rule in significant PCa. A low apparent diffusion coefficient (ADC) value indicates that high Gleason grade tumors are present. Conversely, the absence of any suspicious focus or foci with a high apparent diffusion coefficient value indicates either benign tissue or low-grade tumor
mp-MRI Multiparametric MRI is a highly accurate filter to detect aggressive tumors and to avoid detection of insignificant cancer. There is growing evidence that it may be indicated in any man with an elevated Prostatic Specific Antigen level before considering whether an immediate biopsy should be performed or whether a simple follow-up should be the option.
Although prostate cancer is the second leading cause of cancer death in men in the USA, it can be treated successfully if detected early. Disease management has gradually changed to a paradigm that ...relies on close monitoring through active surveillance in select patients, as well as ongoing refinements in treatment interventions, including minimally invasive procedures. This has resulted in a critical need for a more exacting methodology for performing targeted biopsies, assessing risk levels, and devising treatment strategies. Prostate MRI has emerged as the most precise, state-of-the-art imaging modality for prostate cancer diagnosis and management, thereby creating an immediate demand for radiologists to become proficient in its use. Conceived and edited by a leading authority, with contributions from renowned experts in the field, MRI of the Prostate: A Practical Approach is the first book to tackle this important topic. It provides an overview of the fundamentals of prostate MRI acquisition, interpretation, and reporting. Readers will benefit from a wide range of insightful perspectives gleaned from years of hands-on experience. Key Highlights * Prostate Imaging Reporting and Data System (PI-RADS) for prostate MRI interpretation and cancer risk scoring * Clinical pearls on the optimization and application of prostate MRI for risk assessment, disease staging, MRI-targeted biopsy, recurrent disease, and active surveillance * The emerging utilization of PET and PET/MRI for primary prostate cancer evaluation * More than 700 illustrations with one entirely image-based chapter featuring educational case studies Radiologists will learn how to optimally perform and interpret prostate MRI, and referring physicians will learn to integrate it into day-to-day practice. This book is an essential resource for radiologists and radiology residents, as well as urologists, oncologists, MRI technicians, and other medical practitioners who treat patients with genitourinary disorders.
Accuracy of multiparametric MRI has greatly improved the ability of localizing tumor foci of prostate cancer. This property can be used to perform a TRUS-MR image registration, new technological ...advance, which allows for an overlay of an MRI onto a TRUS image to target a prostate biopsy toward a suspicious area Three types of registration have been developed: cognitive-based, sensor-based, and organ-based registration. Cognitive registration consists of aiming a suspicious area during biopsy with the knowledge of the lesion location identified on multiparametric MRI. Sensor-based registration consists of tracking in real time the TRUS probe with a magnetic device, achieving a global positioning system which overlays in real-time prostate image on both modalities. Organ based registration does not aim to track the TRUS probe, but the prostate itself to compute in a 3D acquisition the TRUS prostate shape, allowing for a registration with the corresponding 3D MRI shape. The concept of an MR-US fusion TB strategy only is gaining more and more widespread acceptance. In a TB only strategy, fewer men could be biopsied overall, with a greater proportion of men diagnosed with clinically significant prostate, as well as fewer men"over diagnosed" with clinically insignificant cancer. However, more clinical research is required before this strategy is ready for widespread adoption.
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