Diagnostic value of MRI-ultrasound fusion-targeted prostate biopsy for non-index lesions combined with the index lesion biopsy.

[PURPOSE] While the clinical value of magnetic resonance imaging (MRI)-ultrasound fusion-targeted prostate biopsy (TB) for index lesions (ILs) has been established, the utility of TB for non-index lesions (nILs) remains unclear. We evaluated the diagnostic benefit of combining TB for nILs (nIL-TB) with TB for ILs (IL-TB) in patients with multiple MRI-identified lesions.

[METHODS] A total of 304 patients with multiple Prostate Imaging-Reporting and Data System (PI-RADS)≥3 lesions who underwent IL-TB, nIL-TB, and systematic biopsy (SB) were included. One or 2 nILs per case, defined as lesions with lower PI-RADS category or smaller size than the IL, were targeted. Detection rates of grade group (GG) ≥2 and GG 1 cancer were compared between different biopsy strategies, and the added values of SB and nIL-TB to IL-TB were assessed. Risk factors for missing GG≥2 cancer in IL-TB and detecting it in nIL-TB were explored using multivariable analysis.

[RESULTS] Detection rates of GG≥2 cancer were 55.9% in IL-TB alone, 70.4% in IL-TB+SB, and 68.8% in IL-TB+nIL-TB, revealing no significant difference in the added value between SB and nIL-TB(14.5% vs.12.8%, p = 0.398). GG 1 cancer was detected more frequently in IL-TB+SB than in IL-TB+nIL-TB(11.5% vs.6.6%, p = 0.004). Small IL volume and IL confined to the transition zone were independent predictors of missing GG≥2 cancer in IL-TB and detecting it in nIL-TB (p = 0.002, odds ratio[OR]=3.07; p = 0.018, OR=2.41).

[CONCLUSION] Combining IL-TB and nIL-TB provides a comparable detection rate of GG≥2 cancer with fewer cores than combined biopsy with IL-TB and SB and avoids the detection of GG 1 cancer. nIL-TB may be an alternative to SB in patients with multiple MRI-identified lesions.