Can the contralateral systematic prostate biopsy be omitted in men with unilateral index lesion on MRI? A single-center retrospective study.

[PURPOSE] The objective of this study was to evaluate the diagnostic efficacy of combining prostate targeted biopsy (TB) with ipsilateral systematic biopsy (iSB) for men with unilateral index lesion on magnetic resonance imaging (MRI).

[METHODS] This single-center, retrospective study included 654 patients with unilateral index lesion (PI-RADS ≥ 3) on MRI who underwent prostate target biopsy combined with 12-core systematic biopsy (SB) between January 2022 to February 2023. The index lesion was defined as the lesion with the highest PI-RADS score or, in cases of multiple lesions with the same highest score, the one with the largest diameter. Ipsilateral systematic biopsy (iSB) was defined as the hemi-lateral systematic biopsy on the same side as the index lesion on MRI, while contralateral systematic biopsy (cSB) was defined as the hemi-lateral systematic biopsy on the opposite side. Kappa consistency analysis was conducted to compare the csPCa detection rates between TB combined with SB (TB + SB) and TB combined with iSB (TB + iSB). The McNemar test was used to compare the csPCa detection rates between TB + iSB and TB + cSB.

[RESULTS] The csPCa detection rate was higher for TB + iSB than for TB + cSB (44.87% vs. 42.73%, P < 0.01). TB + iSB showed greater consistency with TB + SB than TB + cSB (K = 0.975 vs. 0.932). Stratified analysis revealed similar results across PI-RADS scores, PSA levels (< 20 ng/ml), age, and prostate volumes, except for PSA levels > 20 ng/ml (66.67% vs. 68.9%, P < 0.01).

[CONCLUSION] TB + iSB, which omits half of the SB cores, demonstrates extremely high consistency with TB + SB in detecting csPCa in men with unilateral index lesion on MRI, and has a higher csPCa detection rate compared to TB + cSB, indicating its potential to replace TB + SB.