Staging of prostate cancer using 3-dimensional transrectal ultrasound images: a pilot study

We used conventional transrectal ultrasound images for 3-dimensional (D) reconstruction of the prostate, and determined its value in staging clinically localized prostate cancer.

A total of 36 patients with newly diagnosed clinically localized prostate cancer were studied. All patients underwent conventional transrectal ultrasonography with 3-D reconstruction. Images were examined and analyzed blindly, and findings were compared to histopathological staging following radical prostatectomy.

Pathological staging of specimens revealed 15 sites of extracapsular extension in 10 patients, of whom 8 had positive margins and 2 had seminal vesicle invasion. The 3-D imaging identified 12 sites of extracapsular extension in 9 patients with 80% sensitivity, 96% specificity and 90% positive predictive value. Of the 2 patients with seminal vesicle invasion 1 was identified correctly on 3-D images. Overall staging accuracy of 3-D imaging was 94%.

The 3-D reconstruction of conventional transrectal ultrasonography imaging is superior to 2-D imaging for staging localized prostate cancer. However, this advantage relies entirely on the visibility of prostate cancer lesions on conventional ultrasonography. Further studies are warranted to evaluate this technology for the management of prostate cancer.