The Influence of Ultrasound Probe Orientation on Prostate Cancer Detection Rate During Transrectal Ultrasonography-Guided Prostate Biopsy

Abstract

We aim to determine whether end-fire probe orientation (and therefore image orientation and biopsy needle direction) during transrectal ultrasonography-guided prostate biopsy has an effect on the prostate cancer (PCa) detection rate, the number of positive biopsy cores, the proportion of diseased tissue in the samples obtained, and the Gleason score. We compared two different axial image protocols and a sagittal image protocol for PCa yield. We hypothesize that axial probe methods direct more of the biopsy needle through the peripheral zone, the principal site for PCa, and therefore improve PCa yield. A total of 441 patients underwent systematic 12-core biopsy using three different methods by six radiologists at our institution. An axial method using probe angulation, an axial method using probe rotation, and a sagittal method were compared. The axial-angulation method was used in 166 men, the axial-rotation method was used in 125 men, and the sagittal method was used in 150 men. Overall, 58.3% had PCa detected. Axial-rotation techniques showed a 17% greater PCa yield and significantly increased the number of positive biopsy cores relative to the sagittal method (P < 0.001) for all patients and for those with a prostate-specific antigen level <10 ng/mL. Of those with PCa, the number of positive cores, proportion of diseased tissue, and Gleason score were also significantly elevated using this technique (P < 0.05). This study suggests that axial techniques have the potential to increase carcinoma yield and Gleason score, through a greater yield in positive core number and proportion of diseased tissue in the samples obtained.