Faculty Bibliography

CONTEXT/BACKGROUND:- In Gleason score GS (7) prostate cancers, the quantity of Gleason pattern 4 (GP 4) is an important prognostic factor and influences treatment decisions. Magnetic resonance imaging (MRI)-targeted biopsy has been increasingly used in clinical practice. OBJECTIVE:- To investigate whether MRI-targeted biopsy may detect GS 7 prostate cancer with greater GP 4 quantity, and whether it improves biopsy/radical prostatectomy GS concordance. DESIGN/METHODS:- A total of 243 paired standard and MRI-targeted biopsies with cancer in either standard or targeted or both were studied, 65 of which had subsequent radical prostatectomy. The biopsy findings, including GS and tumor volume, were correlated with the radical prostatectomy findings. RESULTS:- More prostate cancers detected by MRI-targeted biopsy were GS 7 or higher. Mean GP 4 percentage in GS 7 cancers was 31.0% ± 29.3% by MRI-targeted biopsy versus 25.1% ± 29.5% by standard biopsy. A total of 122 of 218 (56.0%) and 96 of 217 (44.2%) prostate cancers diagnosed on targeted biopsy and standard biopsy, respectively, had a GP 4 of 10% or greater ( P = .01). Gleason upgrading was seen in 12 of 59 cases (20.3%) from MRI-targeted biopsy and in 24 of 57 cases (42.1%) from standard biopsy ( P = .01). Gleason upgrading correlated with the biopsy cancer volume inversely and GP 4 of 30% or less in standard biopsy. Such correlation was not found in MRI-targeted biopsy. CONCLUSIONS:- Magnetic resonance imaging-targeted biopsy may detect more aggressive prostate cancers and reduce the risk of Gleason upgrading in radical prostatectomy. This study supports a potential role for MRI-targeted biopsy in the workup of prostate cancer and inclusion of percentage of GP 4 in the prostate biopsy reports.

PURPOSE/OBJECTIVE:While MRI-Ultrasound Fusion-targeted biopsy (MRF-TB) allows for improved detection of clinically significant prostate cancer (csPCa), concerning numbers of clinically significant disease are still missed. We hypothesize that a number of these are due to the learning curve associated with MRF-TB. We report results of repeat MRF-TB in men with continued suspicion for cancer and the institutional learning curve in detection of csPCa over time. MATERIALS AND METHODS/METHODS:Analysis of 1813 prostate biopsies in a prospectively acquired cohort of men presenting for prostate biopsy over a 4-year period. All men were offered pre-biopsy MRI and assigned a maximum Prostate Imaging - Reporting and Data System version 2 (PI-RADS) score. Biopsy outcomes of men with suspicious region of interest (ROI) were compared. The relationship between time and csPCa detection was analyzed. RESULTS:csPCa detection rate increased 26% over time in men with PI-RADS 4 and 5 (4/5) ROI. On repeat MRF-TB in men with continued suspicion for cancer, 53% of men with PI-RADS 4/5 ROI demonstrated clinically significant discordance from initial MRF-TB, compared to only 23% of men with PI-RADS 1/2 ROI. Significantly less csPCa were missed or under-graded in the most recent biopsies as compared to the earliest biopsies. CONCLUSION/CONCLUSIONS:High upgrade rates on repeat MRF-TB and increasing cancer detection rate over time demonstrate the significant learning curve associated with MRF-TB. Men with low risk or negative biopsies with persistent concerning ROI should be promptly re-biopsied. Improved targeting accuracy with operator experience can help decrease the number of missed csPCa.

BACKGROUND:The number of prostate biopsy cores that need to be taken from each magnetic resonance imaging (MRI) region of interest (ROI) to optimize sampling while minimizing overdetection has not yet been clearly elucidated. OBJECTIVE:To characterize the incremental value of additional MRI-ultrasound (US) fusion targeted biopsy cores in defining the optimal number when planning biopsy and to predict men who might benefit from more than two targeted cores. DESIGN, SETTING, AND PARTICIPANTS/METHODS:This was a retrospective cohort study of MRI-US fusion targeted biopsies between 2015 and 2017. INTERVENTION/METHODS:MRI-US fusion targeted biopsy in which four biopsy cores were directed to each MRI-targeted ROI. OUTCOMES MEASUREMENTS AND STATISTICAL ANALYSIS/UNASSIGNED:The MRI-targeted cores representing the first highest Gleason core (FHGC) and first clinically significant cancer core (FCSC; GS≥3+4) were evaluated. We analyzed the frequency of FHGC and FCSC among cores 1-4 and created a logistic regression model to predict FHGC >2. The number of unnecessary cores avoided and the number of malignancies missed for each Gleason grade were calculated via clinical utility analysis. The level of agreement between biopsy and prostatectomy Gleason scores was evaluated using Cohen's κ. RESULTS AND LIMITATIONS/CONCLUSIONS:A total of 479 patients underwent fusion targeted biopsy with four individual cores, with 615 ROIs biopsied. Among those, FHGC was core 1 in 477 (76.8%), core 2 in 69 (11.6%), core 3 in 48 (7.6%), and core 4 in 24 men (4.0%) with any cancer. Among men with clinically significant cancer, FCSC was core 1 in 191 (77.8%), core 2 in 26 (11.1%), core 3 in 17 (6.2%), and core 4 in 11 samples (4.9%). In comparison to men with a Prostate Imaging-Reporting and Data System (PI-RADS) score of 5, patients were significantly less likely to have FHGS >2 if they had PI-RADS 4 (odds ratio [OR] 0.287; p=0.006), PI-RADS 3 (OR 0.284; p=0.006), or PI-RADS 2 (OR 0.343; p=0.015). Study limitations include a single-institution experience and the retrospective nature. CONCLUSIONS:Cores 1-2 represented FHGC 88.4% and FCSC 88.9% of the time. A PI-RADS score of 5 independently predicted FHGC >2. Although the majority of cancers in our study were appropriately characterized in the first two biopsy cores, there remains a proportion of men who would benefit from additional cores. PATIENT SUMMARY/UNASSIGNED:In men who undergo magnetic resonance imaging-ultrasound fusion targeted biopsy, the first two biopsy cores diagnose the majority of clinically significant cancers. However, there remains a proportion of men who would benefit from additional cores.