Faculty Bibliography

PURPOSE OF REVIEW: We review recent literature surrounding the use of prebiopsy prostate MRI and MRI-targeted biopsy in men at risk for prostate cancer. RECENT FINDINGS: Large series have strengthened the case for the use of MRI prior to prostate biopsy to maximize the detection of clinically significant disease, reduce the detection of clinically insignificant disease, and allow for tumor localization during targeted biopsy. Prebiopsy MRI followed by targeted biopsy appears to have the ability to overcome the limitations of the standard 12-core template. Use of MRI and targeted biopsy in the setting of a prior negative biopsy is supported by the literature and a recent consensus statement by the American Urological Association and the Society of Abdominal Radiology Prostate Cancer Disease-Focused Panel but is contingent upon the availability and quality of multiparametric MRI acquisition and interpretation. In men with no previous biopsy, MRI and targeted biopsy appears to increase detection of clinically significant disease compared with systematic biopsy while reducing detection of indolent disease. The addition of prostate cancer biomarkers and predictive nomograms may further enhance prebiopsy risk assessment. SUMMARY: Prostate MRI prior to biopsy may guide counseling regarding prostate cancer risk, allow for accurate tumor localization during targeted biopsy, and increase detection of clinically significant cancer while limiting detection of indolent disease. Its use prior to biopsy, in conjunction with biomarkers and predictive nomograms, may allow deferral of biopsy in select cases.

Purpose To test the impact of existing Prostate Imaging Reporting and Data System (PI-RADS) version 2 (V2) decision rules, as well as of proposed adjustments to these decision rules, on detection of Gleason score (GS) 7 or greater (GS >/=7) prostate cancer. Materials and Methods Two radiologists independently provided PI-RADS V2 scores for the dominant lesion on 343 prostate magnetic resonance (MR) examinations. Diagnostic performance for GS >/=7 tumor was assessed by using MR imaging-ultrasonography fusion-targeted biopsy as the reference. The impact of existing PI-RADS V2 decision rules, as well as a series of exploratory proposed adjustments, on the frequency of GS >/=7 tumor detection, was evaluated. Results A total of 210 lesions were benign, 43 were GS 6, and 90 were GS >/=7. Lesions were GS >/=7 in 0%-4.1% of PI-RADS categories 1 and 2, 11.4%-27.1% of PI-RADS category 3, 44.4%-49.3% of PI-RADS category 4, and 72.1%-73.7% of PI-RADS category 5 lesions. PI-RADS category 4 or greater had sensitivity of 78.9%-87.8% and specificity of 75.5%-79.1 for detecting GS >/=7 tumor. The frequency of GS >/=7 tumor for existing PI-RADS V2 decision rules was 30.0%-33.3% in peripheral zone (PZ) lesions upgraded from category 3 to 4 based on dynamic contrast enhancement (DCE) score of positive; 50.0%-66.7% in transition zone (TZ) lesions upgraded from category 3 to 4 based on diffusion-weighted imaging (DWI) score of 5; and 71.7%-72.7% of lesions in both zones upgraded from category 4 to 5 based on size of 15 mm or greater. The frequency of GS >/=7 tumor for proposed adjustments to the decision rules was 30.0%-60.0% for TZ lesions upgraded from category 3 to 4 based on DWI score of 4; 33.3%-57.1% for TZ lesions upgraded from category 3 to 4 based on DCE score of positive when incorporating new criteria (unencapsulated sheetlike enhancement) for DCE score of positive in TZ; and 56.4%-61.9% for lesions in both zones upgraded from category 4 to 5 based on size of 10-14 mm. Other proposed adjustments yielded GS >/=7 tumor in less than 15% of cases for one or more readers. Conclusion Existing PI-RADS V2 decision rules exhibited reasonable performance in detecting GS >/=7 tumor. Several proposed adjustments to the criteria (in TZ, upgrading category 3 to 4 based on DWI score of 4 or modified DCE score of positive; in PZ or TZ, upgrading category 4 to 5 based on size of 10-14 mm) may also have value for this purpose. (c) RSNA, 2016 Online supplemental material is available for this article.

OBJECTIVE: To determine how ipsilateral (ipsi) and contralateral (contra) systematic biopsies (SB) impacts detection of clinically significant versus insignificant prostate cancer (PCa) in men with unilateral MRI lesion undergoing MRI fusion target biopsy (MRF-TB). MATERIALS AND METHODS: 211 cases with one unilateral MRI lesion were subjected to SB and MRF-TB. Biopsy tissue cores from the MRF-TB, ipsi-SB and contra-SB were analyzed separately. RESULTS: A direct relationship was observed between MRI suspicious score (SS) and detection of any cancer, Gleason 6 PCa and Gleason > 6 PCa. MRF-TB alone, MRF-TB + ipsi-SB and MRF-TB + contra-SB detected 64.1%, 89.1% and 76.1% of all PCa, respectively, 53.5%, 81.4% and 69.8% of Gleason 6 PCa, respectively, and 73.5%, 96.0% and 81.6% of Gleason >6 PCa, respectively. MRF-TB + ipsi-SB detected 96% of clinically significant PCa and avoided detection of 18.6% of clinically insignificant PCa. MRF-TB + contra-SB detected 81.6% of clinically significant PCa and avoided detection of 30.2% of clinically insignificant PCa. CONCLUSION: Our study suggests that ipsi-SB should be added to MRF-TB as detection of clinically significant PCa increases with only a modest increase in clinically insignificant PCa detection. Contra-SB in this setting may be deferred since it primarily detects clinically insignificant PCa.

Improvements in prostate MR imaging techniques and the introduction of MR imaging-targeted biopsies have had central roles in prostate cancer (PCa) management. The role of MR imaging has progressed from largely staging patients with biopsy-proven PCa to detecting, characterizing, and guiding the biopsy of suspected PCa. These diagnostic advances, combined with improved therapeutic interventions, have led to a more sophisticated and individually tailored approach to patients' unique PCa profile. This review discusses the MR imaging, a standardized reporting scheme, and the role of fusion-targeted prostate biopsy.

OBJECTIVE: The purpose of this study is to evaluate the roles of self-directed learning and continual feedback in the learning curve for tumor detection by novice readers of prostate MRI. MATERIALS AND METHODS: A total of 124 prostate MRI examinations classified as positive (n = 52; single Prostate Imaging Reporting and Data System [PI-RADS] category 3 or higher lesion showing Gleason score >/= 7 tumor at MRI-targeted biopsy) or negative (n = 72; PI-RADS category 2 or lower and negative biopsy) for detectable tumor were included. These were divided into four equal-sized batches, each with matching numbers of positive and negative examinations. Six second-year radiology residents reviewed examinations to localize tumors. Three of the six readers received feedback after each examination showing the preceding case's solution. The learning curve, plotting accuracy over time, was assessed by the Akaike information criterion (AIC). Logistic regression and mixed-model ANOVA were performed. RESULTS: For readers with and without feedback, the learning curve exhibited an initial rapid improvement that slowed after 40 examinations (change in AIC > 0.2%). Accuracy improved from 58.1% (batch 1) to 71.0-75.3% (batches 2-4) without feedback and from 58.1% to 72.0-77.4% with feedback (p = 0.027-0.046), without a difference in the extent of improvement (p = 0.800). Specificity improved from 53.7% to 68.5-81.5% without feedback and from 55.6% to 74.1-81.5% with feedback (p = 0.006-0.010), without a difference in the extent of improvement (p = 0.891). Sensitivity improved from 59.0-61.5% (batches 1-2) to 71.8-76.9% (batches 3-4) with feedback (p = 0.052), though did not improve without feedback (p = 0.602). Sensitivity for transition zone tumors exhibited larger changes (p = 0.024) with feedback than without feedback. Sensitivity for peripheral zone tumors did not improve in either group (p > 0.3). Reader confidence increased only with feedback (p < 0.001). CONCLUSION: The learning curve in prostate tumor detection largely reflected self-directed learning. Continual feedback had a lesser effect. Clinical prostate MRI interpretation by novice radiologists warrants caution.

CONTEXT: Prostate biopsy (PB) represents the gold standard method to confirm the presence of cancer. In addition to traditional random or systematic approaches, a magnetic resonance imaging (MRI)-guided technique has been introduced recently. OBJECTIVE: To perform a systematic review of complications after transrectal ultrasound (TRUS)-guided, transperineal, and MRI-guided PB. EVIDENCE ACQUISITION: We performed a systematic literature search of Web of Science, Embase, and Scopus databases up to October 2015, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Complications and mortality following random, systematic, and image-guided PBs were reviewed. Eighty-five references were included. EVIDENCE SYNTHESIS: The most frequent complication after PB was minor and self-limiting bleeding (hematuria and hematospermia), regardless of the biopsy approach. Occurrence of rectal bleeding was comparable for traditional TRUS-guided and image-guided PBs. Almost 25% of patients experienced lower urinary tract symptoms, but only a few had urinary retention, with higher rates after a transperineal approach. Temporary erectile dysfunction was not negligible, with a return to baseline after 1-6 mo. The incidence of infective complications is increasing, with higher rates among men with medical comorbidities and older age. Transperineal and in-bore MRI-targeted biopsy may reduce the risk of severe infectious complications. Mortality after PB is uncommon, regardless of biopsy technique. CONCLUSIONS: Complications after PB are frequent but often self-limiting. The incidence of hospitalization due to severe infections is continuously increasing. The patient's general health status, risk factors, and likelihood of antimicrobial resistance should be carefully appraised before scheduling a PB. PATIENT SUMMARY: We reviewed the variety and incidence of complications after prostate biopsy. Even if frequent, complications seldom represent a problem for the patient. The most troublesome complications are infections. To minimize this risk, the patient's medical condition should be carefully evaluated before biopsy.