Related Experiment Video
Updated: Jun 30, 2026
A Cognitive Fusion-guided Prostate Biopsy Using Multiparametric Magnetic Resonance Imaging and Transrectal Ultrasound
Published on: March 21, 2025
Ipsilateral sampling maintains clinically significant cancer detection and reduces overdiagnosis in PI-RADS 4-5
Cassandra Jeavons1, Kevin An2, Yilin Zhang1
1Department of Radiology, University of British Columbia, Vancouver General Hospital, Vancouver, British Columbia, Canada.
Background:
Men with unilateral PI-RADS 4-5 lesions routinely undergo targeted and systematic biopsy, increasing detection of clinically insignificant cancer (ciPCa). Whether contralateral systematic cores add meaningful clinically significant cancer (csPCa) yield remains uncertain.
Purpose:
To determine whether contralateral systematic biopsy (SB) can be omitted in men with unilateral PI-RADS 4-5 lesions by comparing targeted biopsy (TB), TB+ipsilateral SB (iSB), and TB+full SB for csPCa detection.
Methods:
We retrospectively reviewed 834 men undergoing MRI-ultrasound fusion biopsy from May 2020-February 2023. Three hundred had a single unilateral PI-RADS 4 (n = 206) or PI-RADS 5 (n = 94) lesion. Detection rates for csPCa and ciPCa were compared across TB, TB+iSB, and TB+SB. Sensitivity for csPCa used TB+SB as reference. Adverse pathological features and diagnostic trade-offs were assessed.
Results:
Adding iSB to TB significantly increased csPCa detection (47.7% vs. 42.0%, P < 0.001), with no further gain from TB+SB (49.0%, P = 0.130). Systematic sampling markedly increased ciPCa (22.0% (TB) vs. 49.3% (TB+iSB) vs. 62.7% (TB+SB), P < 0.001). Sensitivity improved from 85.7% (TB) to 97.3% (TB+iSB) (P < 0.001), again without benefit from TB+SB. iSB also improved identification of adverse features, including cribriform architecture (23.1% vs. 36.7%, P < 0.001). Incremental analysis showed iSB captured nearly all diagnostic gains while limiting overdiagnosis; 75 contralateral cores were required to detect one additional csPCa at the cost of 7.5 ciPCa.
Conclusion:
TB+iSB improves csPCa detection while avoiding the marginal yield and substantial ciPCa overdiagnosis associated with contralateral sampling. Extending to TB+SB yields only ∼1.3 additional MRI-invisible csPCa but 13.3 additional ciPCa per 100 men.
