Staging of prostate cancer using three-dimensional TRUS imaging: A pilot study
Hamdy PC., Fording B., Neal DE., Humphries K.
Introduction: TRUS imaging of the prostate is an established method of diagnosis and staging in prostate cancer. However, the sensitivity of the technique is limited. In an attempt to overcome this limitation, we developed and tested a new three-dimensional (3-D) imaging technique of the prostate using conventional TRUS equipment. Patients and methods: To date, 10 men have been investigated: two patients had benign disease and eight had prostate cancer. Of the latter, one had locally advanced disease and six localized prostate cancer on conventional TRUS and underwent radical prostatectomy. A standard Bruel and Kjaer test rig/holder was used to move a transrectal probe axially in 2.5 mm steps for a total of about 25 positions. At each position, an ultrasonogram was acquired using a PC workstation with an installed videocapture card and associated image-processing package. The 3-D reconstructed image was matched with the pathological staging. Results: The system was tested on the two patients with benign prostates to familiarize the authors with the anatomical appearances on 3-D imaging. Both 2-D and 3-D imaging were equally effective in staging the patient witli locally advanced prostate cancer. Of the seven patients who underwent radical prostatectomy, two had extracapsular disease on pathological staging. In both cases, analysis of the 3-D images, while unaware of origin, allowed the detection of extracapsular disease on several images, which was not apparent on 2-D TRUS. Conclusions: 3-D imaging, using reconstructed transverse scans from conventional TRUS, is able to detect extracapsular disease in prostate cancer that otherwise appears localized on 2-D imaging. The technique requires limited additional equipment and warrants further assessment. © 1997 British Journal of Urology.