Prospective randomized multicenter study comparing prostate cancer detection rates of end-fire and side-fire transrectal ultrasound probe configuration.

Objective: To prospectively test the hypothesis that end-fire transrectal ultrasound prostate biopsy probes have greater cancer detection rates than side-fire probes. Retrospective studies have suggested that such probes might have greater cancer detection rates.

Methods: The present prospective randomized multicenter trial aimed to compare the prostate cancer detection rates of the end-fire versus side-fire probe configuration during transrectal ultrasound-guided 12-core prostate biopsy. Patients were randomized according to age, prostate-specific antigen level and prostate volume. An interim analysis was planned after the inclusion of 300 patients.

Results: At the interim analysis after the inclusion of 297 patients, no differences were found in the mean prostate-specific antigen level (P = .412), mean age (P = .519), mean prostate volume (P = .730), and positive digital rectal examination findings (P = .295). The prostate cancer detection rate did not differ between the end-fire and side-fire probe (34.3% vs 34.4%, P = .972). On multivariate analysis, suspicious digital rectal examination findings (relative risk 8.185, P < .001), prostate-specific antigen level (relative risk 1.051, P = .041), and prostate volume (relative risk 0.973, P < .001), but not probe configuration (relative risk 0.942, P = .831), were independent predictive factors for the detection of prostate cancer. The interim analysis committee suggested that, because no difference of 5 absolute percent was achieved after 300 patients, no additional recruitment was necessary. Therefore, the study was terminated early.

Conclusion: The results of the present study have shown that the transrectal ultrasound probe configuration does not affect the prostate cancer detection rate during transrectal ultrasound-guided prostate biopsy.