Faculty Bibliography

Background: Traditional pathology reports of prostate biopsy mainly focus on presence of carcinoma but ignore other pathologic findings such as inflammation or hyperplasia. In the era of MRI-ultrasound fusion-targeted prostate biopsy (MRF-TB), where specific MRI regions of interest (ROI) are targeted for biopsy, these benign findings should be reported as they may guide decisions on when to repeat imaging or prostate biopsy. In this study, we reviewed MRF-TB prostate biopsies reported as negative for carcinoma to identify pathologic correlates to visible ROI on prostate MRI. Design: From 2012 to2016, 1595 men underwent a total of 1813 prebiopsy prostate MRI, followed by MRF-TB at our institution. We rereviewed the prostate biopsy cores for all patients with PI-RADS 4 or 5 (PI-RADS 4/5) ROI but had no cancer detected on MRF-TB. Pathologic findings were separated into two groups: significant pathologic findings (SPF, such as inflammation, hyperplasia, ASAP/HGPIN) and no significant pathologic findings (NSPF) with or without cancer in same/adjacent site on systematic biopsy (SB). Patients with repeat MRI and follow-up MRF-TB evaluation. Results: 497 men had PI-RADS 4/5 lesions out of 1595 initial biopsies. Of these 497 men, 101 (20%) had MRF-TB negative for carcinoma. Upon review, 54 had SPF and 47 had NSPF on MRF-TB. Of 54 men with SPF on initial MRF-TB, 31 had repeat MRI, 23 of 31 men downgraded in which 16 had repeat MRF-TB with 1 had cancer detect. The other 8 of 31 men had persistent PI-RADS 4/5 lesions, 3 were detected cancer on repeat MRF-TB. Of 47 men with NSPF on initial MRF-TB, 19 had PCa in the same/ adjacent site on SB and were considered as missed on MRF-TB; of the other 28, 13 underwent repeat MRI. 8 of 13 downgraded with 0 had PCa in the repeat MRF-TB and 5 of 13 men with persistent PI-RADS 4/5 lesions, 3 had PCa detect on repeat MRF-TB. Altogether, 22/47 (47%) of the cases with NSPF in the initial MRF-TB were missed cancer. Conclusions: 1/5 of the target biopsy cases on PI-RADS 4/5 ROI had negative cancer detection. Inflammation, nodular hyperplasia and HGPIN can account for some of the cases, and those were downgraded in followup MRI usually had a negative repeat biopsy. Cases with NSPF on MRF-TB for PI-RADS 4/5 lesions are likely (47%) missed PCa, high likelihood of persistent PI-RADS 4/5 ROI on repeat MRI and PCa detection on repeat biopsy. We suggest pathology findings beside cancer should be reported on MRF-TB biopsy as they can guide decisions on repeat imagine and biopsy

OBJECTIVE: To develop nomograms that predict the probability of overall PCa and clinically significant PCa (Gleason >/=7) on MRI targeted, and combined MRI-targeted and systematic, prostate biopsy. MATERIALS AND METHODS: From June 2012 to August 2014, MR-US fusion targeted prostate biopsy was performed on 464 men with suspicious regions identified on pre-biopsy 3T MRI along with systematic 12 core biopsy. Logistic regression modeling was used to evaluate predictors of overall and clinically significant PCa, and corresponding nomograms were generated for men who were not previously biopsied or had one or more prior negative biopsies. Models were created with 70% of a randomly selected training sample and bias-corrected using bootstrap resampling. The models were then validated with the remaining 30% testing sample pool. RESULTS: A total of 459 patients were included for analysis (median age 66 years, PSA 5.2 ng/ml, prostate volume 49 cc). Independent predictors of PCa on targeted and systematic prostate biopsy were PSA density, age, and MRI suspicion score. PCa probability nomograms were generated for each cohort using the predictors. Bias-corrected areas under the receiver-operating characteristic curves for overall and clinically significant PCa detection were 0.82 (0.78) and 0.91 (0.84) for men without prior biopsy and 0.76 (0.65) and 0.86 (0.87) for men with a prior negative biopsy in the training (testing) samples. CONCLUSION: PSA density, age, and MRI suspicion score predict prostate cancer on combined MRI-targeted and systematic biopsy. Our generated nomograms demonstrate high diagnostic accuracy and may further aid in the decision to perform biopsy in men with clinical suspicion of PCa.

PURPOSE: This study aimed to assess variability in imaging facilities' adherence to the minimum technical standards for prostate magnetic resonance imaging acquisition established by Prostate Imaging-Reporting and Data System (PI-RADS) version 2 (v2). METHODS: A total of 107 prostate magnetic resonance imaging examinations performed at 107 unique imaging facilities after the release of PI-RADS v2 and that were referred to a tertiary care center for secondary interpretation were included. Image sets, DICOM headers, and outside reports were reviewed to assess adherence to 21 selected PI-RADS v2 minimum technical standards. RESULTS: Hardware arrangements were 23.1%, 1.5T without endorectal coil; 7.7%, 1.5T with endorectal coil; 63.5%, 3T without endorectal coil; and 5.8%, 3T with endorectal coil. Adherence to minimum standards was lowest on T2 weighted imaging (T2WI) for frequency resolution /=1400 s/mm2) images were included in 58.0% (calculated in 25.9%). Adherence to T2WI phase resolution and DWI inter-slice gap were greater (P < .05) at 3T than at 1.5T. Adherence did not differ (P > .05) for any parameter between examinations performed with and without an endorectal coil. Adherence was greater for examinations performed at teaching facilities for T2WI slice thickness and DCE temporal resolution (P < .05). Adherence was not better for examinations performed in 2016 than in 2015 for any parameter (P > .05). CONCLUSION: Facilities' adherence to PI-RADS v2 minimum technical standards was variable, being particularly poor for T2WI frequency resolution and DCE temporal resolution. The standards warrant greater community education. Certain technical standards may be too stringent, and revisions should be considered.

OBJECTIVE: The purpose of this study was to compare the reproducibility and diagnostic performance of 2D and 3D ROIs for prostate apparent diffusion coefficient (ADC) measurements. MATERIALS AND METHODS: The study included 56 patients with prostate cancer undergoing 3-T MRI including DWI (b = 50 and 1000 s/mm2) before radical prostatectomy. Histologic findings from prostatectomy specimens were reviewed to denote each patient's dominant tumor and a benign region with visually decreased ADC. Three readers independently measured the ADCs of both areas using an ROI placed on a single slice through the lesion (2D) and an ROI encompassing all slices through the lesion (3D). Readers repeated measurements after 3 weeks. Assessment included Bland-Altman analysis (coefficient of repeatability [CR] in which lower values indicated higher reliability) and ROC analysis. RESULTS: For intrareader variability, the CRs across readers for all ROIs were 9.9% for 2D and 9.3% for 3D. For tumor ROIs the CRs were 10.6% for 2D and 9.6% for 3D. For interreader variability, the CRs across readers for all ROIs were 17.1% for 2D and 20.5% for 3D and for tumor ROIs were 17.9% for 2D and 22.2% for 3D. For combined reader data, the AUCs for benign and malignant findings were 0.77 for 2D and 0.78 for 3D (p = 0.146). For differentiating Gleason score (GS) 3 + 3 from GS > 3 + 3 tumors, the AUCs were 0.92 for 2D and 0.92 for 3D ROIs (p = 0.649). For differentiating GS /= 4 + 3 tumors, the AUCs were 0.70 for 2D and 0.67 for 3D ROIs (p = 0.004). CONCLUSION: Use of a 3D ROI did not improve intrareader or interreader reproducibility or diagnostic performance compared with use of a 2D ROI for prostate ADC measurements. Interreader reproducibility of 2D ROIs was suboptimal nonetheless.

OBJECTIVE: The purpose of this study is to compare radiologists' and urologists' opinions regarding prostate MRI reporting. SUBJECTS AND METHODS: Radiologist members of the Society of Abdominal Radiology and urologist members of the Society of Urologic Oncology received an electronic survey regarding prostate MRI reporting. RESULTS: The response rate was 12% (135/1155) for Society of Abdominal Radiology and 8% (54/663) for Society of Urologic Oncology members. Most respondents in both specialties prefer Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) (radiologists, 84%; urologists, 84%), indicate that it is used at their institution (radiologists, 84%; urologists, 78%), understand its implications for patient care (radiologists, 89%; urologists, 71%), and agree that radiologists apply PI-RADSv2 categories correctly (radiologists, 57%; urologists, 61%). Both specialties agreed regarding major barriers to PI-RADSv2 adoption: radiologist inexperience using PI-RADSv2 (radiologists, 51%; urologists, 51%), urologist inexperience using PI-RADSv2 (radiologists, 46%; urologists, 51%), and lack of standardized templates (radiologists, 47%; urologists, 52%). The specialties disagreed (p