Patient Position for TRUS-Guided Prostate Biopsy
The left lateral decubitus position is the standard recommended position for transrectal ultrasound (TRUS)-guided prostate biopsy. 1
Standard Positioning Protocol
The left lateral decubitus position is explicitly recommended in clinical guidelines for TRUS-guided prostate biopsy procedures. 1 This positioning allows optimal access for the transrectal ultrasound probe and biopsy needle while maintaining patient comfort during the procedure. 1
Evidence Supporting Left Lateral Decubitus Position
Pain and tolerability data favor the lithotomy position over lateral decubitus, though guidelines still recommend lateral positioning. 2, 3 Two comparative studies found:
- Lithotomy position resulted in lower pain scores (median VAS 30 vs 45) and better patient willingness to undergo repeat procedures (96.6% vs 86.7%) compared to left lateral decubitus. 2, 3
- Patients in lithotomy position required less additional analgesia (14.3% vs 37.1%) and experienced less post-biopsy hematuria. 3
- However, despite these findings, the established guideline recommendation remains left lateral decubitus position for standard TRUS-guided biopsy. 1
Alternative Positioning for MRI-Guided Biopsies
For MRI-guided prostate biopsies, the supine position is preferred and technically feasible. 4, 5 This differs from standard TRUS-guided procedures because:
- Supine positioning is more patient-friendly and comfortable during prolonged MRI procedures. 4
- Dedicated MR-compatible biopsy devices allow successful supine positioning without modifying the MRI table. 4
- Positional changes between supine diagnostic MRI and lateral decubitus biopsy can cause prostate translocation ≥5 mm in 20% of patients, potentially affecting targeting accuracy. 6
Clinical Pitfalls to Avoid
Do not assume patient position is irrelevant to procedural outcomes. Position affects both patient comfort and technical accuracy:
- The prostatic base demonstrates the largest positional differences between supine and lateral positions. 6
- Larger bladder volumes can minimize prostate translocation in the latero-lateral direction. 6
- When using MRI/US fusion guidance, be aware that position-related prostate translocation compounds software misregistration errors. 6