Diagnostic Yield of Incremental Biopsy Cores and Second Lesion Sampling for In-Gantry MRI-Guided Prostate Biopsy

In-gantry MRI-guided biopsy (MRGB) of the prostate has been shown to be more accurate than other targeted prostate biopsy methods. However, the optimal number of cores to obtain during in-gantry MRGB remains undetermined. To assess the diagnostic yield of incremental cores of the primary lesion and of second lesion sampling during in-gantry MRGB of the prostate. This retrospective study included 128 men with a total of 163 prostate lesion who underwent in-gantry MRGB between 2016 and 2019. The men had a total of 163 lesions sampled with ≥2 cores, 121 lesions sampled with ≥3 cores, and 52 lesions sampled with ≥4 cores. A total of 40 men underwent sampling of a second lesion. Upgrade on a given core was defined as a greater International Society of Urologic Pathology Grade Group (ISUP-GG) relative to the previously obtained cores. Clinically significant cancer (csPCa) was defined as ISUP-GG 2 or greater. The frequency of any upgrade was 12.9% (21/163) on core 2, versus 10.7% (13/121) on core 3 (p=.29 relative to core 2) and 1.9% (1/52) on core 4 (p=.03 relative to core 3). The frequency of upgrade to csPCa was 7.4% (12/163) on core 2, versus 4.1% (5/121) on core 3 (p=.13 relative to core 2), and 0.0% (0/52) on core 4 (p=.07 relative to core 3). The frequency of upgrade on core 2 was higher for anterior lesions (p