Does the transrectal ultrasound probe influence prostate cancer detection in patients undergoing an extended prostate biopsy scheme? Results of a large retrospective study.

Objective: • To compare the prostate cancer detection rate and tolerance profile between a transrectal biopsy made with a 'side fire' (SF) and an 'end fire' (EF) ultrasound probe.

Patients And Methods: • We selected patients undergoing first biopsy and re-biopsy of the prostate with a 14- and 18-core template using EF and SF transrectal probes, respectively. • We compared the cancer detection rate between the two probes on first biopsy and re-biopsy and gauged patient tolerance using a visual analogue scale (VAS).

Results: • A total of 1705 patients were included in the first biopsy group, while 487 were in the re-biopsy group. • The overall detection rate of first biopsy was 37.2%; the overall detection rate of re-biopsy was 10.1%. • No significant difference was found between the two probes in the first biopsy and re-biopsy sets (38% vs 36.5%, P= 0.55; 10.8% vs 9.3%, P= 0.7). • The lack of any significant association between the type of probe used and prostate cancer detection was confirmed by univariable and multivariable analyses in both the first biopsy and re-biopsy sets after accounting for prostate-specific antigen values, per cent free prostate-specific antigen, digital rectal examination, and prostate and transition zone volumes. • The patient tolerance profile of the SF group was significantly better than that of the EF group (mean VAS 1.78 ± 2.01 vs 1.45 ± 2.21; P= 0.02).

Conclusion: • The prostate cancer detection rate does not depend on the type of probe used. However, the SF transrectal probe is associated with a better patient tolerance profile.