Accuracy is Key: Transrectal Ultrasound Versus Magnetic Resonance Imaging to Determine Prostatic Volume.

Area of Science:

• Urology
• Medical Imaging
• Oncology

Background:

• Accurate prostate sizing is crucial for surgical planning, including prostatectomy.
• Transrectal ultrasound (TRUS) and magnetic resonance imaging (MRI) are primary imaging modalities for the prostate.
• The comparative accuracy of TRUS and MRI for prostate volume estimation requires further clinical validation.

Purpose of the Study:

• To compare the accuracy of transrectal ultrasound (TRUS) and magnetic resonance imaging (MRI) in estimating prostate volume against actual prostate weight.
• To evaluate the clinical significance of imaging modality differences in patients with prostate cancer undergoing robotic-assisted radical prostatectomy.

Main Methods:

• Retrospective analysis of 147 men with prostate cancer who underwent robotic prostatectomy.
• Preoperative prostate size measurements using both transrectal ultrasound (TRUS) and magnetic resonance imaging (MRI).
• Prostate gross specimen weight obtained post-robotic prostatectomy for comparison.

Main Results:

• Both TRUS and MRI significantly underestimated prostate volume compared to actual weight (p < 0.001).
• MRI (mean difference -9.5 mL) was more accurate than TRUS (mean difference -14.4 mL), with a statistically significant difference between modalities (p < 0.001).
• No significant difference in prostate weight or estimated volume was observed between high-grade and non-high-grade cancer groups.

Conclusions:

• Transrectal ultrasound (TRUS) and magnetic resonance imaging (MRI) both underestimate prostate volume.
• While MRI shows slightly higher accuracy, the difference is small, making TRUS an adequate imaging tool for prostate cancer management.
• Prostate cancer grade does not appear to influence the accuracy of imaging-based volume estimations.