Effect of targeted biopsy guided by elastic image fusion of MRI with 3D-TRUS on diagnosis of anterior prostate cancer.

Purpose: To evaluate the effect of targeted biopsy (TB) with elastic fused magnetic resonance imaging (MRI) and 3-dimensional transrectal ultrasound (3D-TRUS) guidance in the diagnosis of anterior prostate cancer (APCa).

Material And Method: A retrospective study was performed on patients who underwent TB with elastic fused MRI/3D-TRUS guidance using a 1.5-T MRI with T2- and diffusion-weighted images. APCa was defined as TB-proven cancer whose MR-imaged center was located anteriorly according to standardized MRI reporting schema. Prostate Imaging Reporting and Data System was used to quantify MRI suspicion. Maximum cancer core length (MCCL), cancer core involvement, primary Gleason grade pattern, and Gleason score (GS) on TB were assessed. A clinically significant cancer on TB was MCCL ≥ 5mm of GS 6 or any cancer with GS ≥ 7. Agreement between TB and radical prostatectomy step sections was assessed for all subjects when possible.

Results: A total of 211 consecutive subjects were included. APCa was found in 81% (170/211). Median (range) of TB per patient, MCCL, and cancer core involvement were 2 (1-5), 10mm (4-23), and 57% (10%-100%), respectively. According to the level of MRI suspicion, positive rate for any cancer vs. clinically significant cancer was 96% (114/119) vs. 86% (102/119) for highly suspicious, 80% (46/57) vs. 68% (39/57) for likely, and 29% (10/35) vs. 20% (7/35) for equivocal, respectively (P = 0.016 and<0.001). Step-section analysis was possible for 70 patients. Concordance of primary Gleason grade pattern and GS between TB and radical prostatectomy was 90% (κ = 0.7) and 77% (κ = 0.64), respectively.

Conclusion: TB with elastic fused MRI/3D-TRUS guidance significantly enhanced accuracy in diagnosing clinically significant APCa.