Relationship Between Prebiopsy Multiparametric Magnetic Resonance Imaging (MRI), Biopsy Indication, and MRI-ultrasound Fusion–targeted Prostate Biopsy Outcomes

Abstract

BACKGROUND Increasing evidence supports the use of MRI-ultrasound fusion-targeted prostate biopsy (MRF-TB) to improve the detection of clinically significant prostate cancer (PCa) while limiting detection of indolent disease compared to systematic 12-core biopsy (SB). OBJECTIVE We report results of MRF-TB and SB and the relationship between biopsy outcomes and pre-biopsy MRI in 601 men presenting to our center. DESIGN/SETTING/PARTICIPANTS Retrospective analysis of a prospectively acquired cohort of men presenting for prostate biopsy over a 26-month period. A total of 601 of 803 consecutively eligible men were included. INTERVENTIONS All men were offered pre-biopsy MRI and assigned a maximum MRI suspicion score (mSS). Men with an MRI abnormality underwent combined MRF-TB and SB. OUTCOMES Detection rate of all PCa and high-grade PCa (Gleason score (GS)≥7) were compared by McNemar's test. RESULTS MRF-TB detected fewer GS6 PCa (75 vs 121, p<0.001) and more GS≥7 PCa (158 vs 117, p<0.001) than SB. Increasing mSS was associated with increasing detection of GS≥7 PCa (p<0.001), but had no relationship to the detection of GS6 PCa. The prediction of GS≥7 disease by mSS varied according to biopsy history. Compared to SB, MRF-TB identified more GS≥7 cancer in men with no prior biopsy (88 vs 72, p=0.012), with prior negative biopsy (28 vs 16, p=0.010), and with prior cancer diagnosis (42 vs 29, p=0.043). MRF-TB detected fewer GS6 cancers in men with no prior biopsy (32 vs 60, p<.001) and prior cancer (30 vs 46, p=0.034). Limitations include retrospective design and potential for selection bias given a referral population. CONCLUSIONS MRI-US fusion-targeted biopsy detects more high-grade cancer than systematic biopsy while limiting detection of GS6 cancer in men presenting for prostate biopsy. These findings suggest that pre-biopsy mpMRI and MRF-TB should be considered in all men undergoing prostate biopsy and, in conjunction with biopsy indication, mSS may ultimately help identify a select group of men at low risk of high-grade cancer in whom prostate biopsy may not be warranted.