Faculty Bibliography

CONTEXT:The diagnostic accuracy of multiparametric magnetic resonance imaging (mpMRI) for prostate cancer (PCa) diagnosis has been extensively explored. Little is known about the prognostic value of mpMRI suspicion scores and other quantitative mpMRI information. OBJECTIVE:To systematically review the current literature assessing the relationship between pretreatment mpMRI and oncological outcomes after primary treatment for PCa to assess the role of mpMRI as a prognostic tool. EVIDENCE ACQUISITION:A computerized bibliographic search of MEDLINE/PubMed, EMBASE, Scopus, and the Cochrane Library CENTRAL databases was performed for all studies assessing the relationship between mpMRI and oncological outcomes after primary treatment for PCa. The review protocol is registered in the PROSPERO database (CRD42020209899). EVIDENCE SYNTHESIS:A total of six studies were included. Reliable evidence is still limited in this field. The Prostate Imaging-Reporting and Data System (PI-RADS) score was an independent predictor of biochemical recurrence (BCR) after radical prostatectomy (RP) in the majority of the studies included. The tumor volume at mpMRI was not significantly associated with BCR after RP for PCa. Data on disease progression and PCa-specific mortality are limited. Heterogeneity among the studies was substantial. CONCLUSIONS:The review shows that PI-RADS scores provide information on the future likelihood of cancer recurrence or progression, at least for men undergoing RP. We are of the view that this information should be taken into account to identify men at higher risk of unfavorable outcomes. PATIENT SUMMARY:A higher Prostate Imaging-Reporting and Data System score for magnetic resonance imaging of the prostate seems to be positively associated with oncological failure in prostate cancer and should be incorporated into future risk models.

Focal therapy is growing as an alternative management options for men with clinically localized prostate cancer. Parallel to the increasing popularity of active surveillance (AS) as a treatment for low-risk disease, there has been an increased interest towards providing focal therapy for patients with intermediate-risk disease. Focal therapy can act as a logical "middle ground" in patients who seek treatment while minimizing potential side effects of definitive whole-gland treatment. The aim of the current review is to define the rationale of focal therapy in patients with intermediate-risk prostate cancer and highlight the importance of patient selection in focal therapy candidacy.

PURPOSE/OBJECTIVE:A benign MRI-targeted prostate biopsy (MRF-TB) in the setting of a PI-RADS 4/5 abnormality presents a clinical dilemma for future management. We evaluated benign histologic features on MRF-TB to determine if they predict the likelihood of missed cancer on subsequent biopsy. MATERIALS AND METHODS/METHODS:Between 6/2012 and 9/2016, 1595 men were enrolled in a prospective study of MRI-targeted and systematic biopsy outcomes. We re-reviewed pathology from benign MRF-TB of PI-RADS 4/5 abnormalities and divided into 5 groups for comparison to outcomes of clinical follow-up: inflammation (38%), stroma/glandular hyperplasia (9%), normal prostate tissue (28%), ASAP/HGPIN (9%), and cancer in adjacent systematic cores (16%). RESULTS:88/497 (18%) men with PI-RADS 4/5 abnormality prior to initial biopsy had no cancer on MRF-TB. In follow-up, 45 men underwent repeat MRI: 12 (27%) had persistent PI-RADS 4/5 abnormalities, 17 (38%) had PI-RADS 2/3, 16 (35%) had PI-RADS 1. On repeat MRF-TB, cancer was found in 62.5% of men with PI-RADS 4/5 and 23% of men with PI-RADS 2/3. Histologic groups on initial MRF-TB were not predictive of the likelihood of PI-RADS downgrade on repeat MRI or cancer detection on repeat biopsy. CONCLUSIONS:Among men with no cancer on MRF-TB performed for PI-RADS abnormality, downgrade of PI-RADS score is noted in 73% on repeat MRI. Persistence of PI-RADS 4/5 predicts a higher risk of missed cancer, warranting prompt re-biopsy. While histologic findings such as inflammation may underlie some PI-RADS 4/5 abnormalities, initial histology is a poor predictor of cancer likelihood on repeat biopsy.

PURPOSE/OBJECTIVE:To demonstrate the generalizability of PRECISION findings and apply the PRECISION biopsy strategy to a contemporary cohort to characterize cancers missed by employing this strategy. MATERIALS AND METHODS/METHODS:629 men biopsied between 2/2015-9/2018 met PRECISION inclusion criteria. Men with PI-RADS 1-2 MRI were only biopsied if high clinical suspicion for cancer. Missed cancers were defined as prostate cancer (PCa) identified uniquely on systematic biopsy (SB) in men with PI-RADS 3-5 MRI, or on either SB or MRI-targeted prostate biopsy (MRI-TB) in men with PI-RADS 1-2 MRI. Outcomes included 1) clinically-significant PCa (csPCa), ≥Gleason grade group (GG) 2, detection rate (CDR), 2) missed csPCa rate upon application of PRECISION biopsy strategy, 3) GG distribution, core size, spatial orientation, and oncologic risk among missed cancers. RESULTS:Application of the PRECISION biopsy strategy to the study cohort resulted in avoidance of biopsy in 28%, similar MRI-TB CDR to PRECISION, reduction of GG1 CDR by 60%, and reduction of csPCa CDR by 19%. Missed csPCa were often <6 mm (54.5%), GG2 (67.3%), and low-risk by clinical nomogram (74.6%). GG1 cancers identified uniquely on SB were often contralateral to MRI target (46.4%), while missed csPCa was predominantly ipsilateral (81%). Limitations include biopsy of only men with high-risk clinical features among PIRADS 1-2 MRI, potentially overestimating the csPCa CDR. CONCLUSIONS:The study cohort demonstrated generalizability of PRECISION findings. Applying the PRECISION biopsy strategy greatly reduces GG1 CDR, while missing a small number of csPCa, typically small volume, low-risk, and GG2. Missed csPCa are predominantly ipsilateral to MRI target, possibly representing targeting error.

Introduction & Objectives: AUA, EAU and NICE now recommend multiparametric (mp)MRI prior to all prostate biopsies, including initial. This creates a massive increase in demand on the limited resource of access to MRI. Biparametric (bp)MRI, without dynamic contrast enhancement (DCE) series, is rapidly gaining interest as a faster, cheaper, less invasive way of performing prostate MRI with the goal of maintaining diagnostic accuracy. Using an online training tool, the global BooMeR Study assesses accuracy and variation in reading of bpMRI.
Material(s) and Method(s): A free bpMRI version of the online mpMRI training program MRI PRO (prostatemristudy.com) was promoted via email, Twitter and LinkedIn from August to October 2019 to target radiologists and urologists around the world. MRI PRO is an interactive program which matches 300 prostate mpMRIs acquired and reported to PIRADS v.2 standard to wholemount radical prostatectomy in positive MRIs and template transperineal biopsy histology for negative MRIs. The bpMRI version matches 50 cases, without any DCE series. We designated true PIRADS 4 or 5 as true positive and true PIRADS 1 or 2 as true negative. True PIRADS 3 (equivocal) cases were excluded from analysis. MRI PRO's proprietary analysis tool was used to compare users' responses.
Result(s): 59 prostate MRI readers registered for the study. 33% were radiologists, 67% were urologists and all respondents were consultants or fellows. 59%, 12%, 9%, 20% were from Europe, Asia-Pacific, North America, or elsewhere, respectively. 33% had previously read over 100 prostate mpMRIs. A total of 1,090 cases were completed, for a mean of 18.4 cases per reader. 15 readers completed all 50 cases. The overall specificity and sensitivity was 78% and 71% respectively. Cohorts of experienced vs inexperienced readers were then compared where readers who had performed more than 4 cases were included. Readers with over 100 previous cases of experience [n=13] had specificity of 77.7% (95% CI 70.9 - 84.4) and sensitivity of 77.2% (95% CI 70.2, 84.2). Readers with less than 100 previous cases of experience [n=18] had a specificity of 53.8%, 95% CI [41.9%, 65.7%] and sensitivity of 64.4%, 95% CI [59.9%, 68.8%]. The difference in sensitivity (p=0.044) and specificity (p=0.003) between the two cohorts were statistically significant). PIRADS 3 reporting was 3.9% vs 8.2% in the experienced vs inexperienced groups.
Conclusion(s): Preliminary BooMeR Study results suggest variation in bpMRI reporting accuracy and likelihood of reporting PIRADS 3 are associated with reader experience. Adequate training and quality assurance in reporting bpMRI is essential.
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