Istituto Scientifico Ospedale San Raffaele - Urology, Milan, Italy.Istituto Scientifico Ospedale San Raffaele - Pathology, Milan, Italy; ABC Medical School - Urology, Santo André, Sao Paulo, Brazil.
Study Type - Diagnostic (exploratory cohort) Level of Evidence 2b.
What's known on the subject? and What does the study add? The influence of transrectal probe system, end-fire and side-fire, has not been studied in detail. Using a sextant biopsy template it has been demonstrated a difference between end-fire and side-fire modes in 4-10 ng/mL PSA interval population. No studies evaluated the results in extended biopsy templates before. This study adds the knowledge that end-fire and side-fire transrectal probe, which are the two probe systems to perform transrectal prostate biopsy, have similar results in terms of prostate cancer detection rate and can be indifferently employed in extended prostate biopsy templates used in daily practice.
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.
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).
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).
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.
Raber M, Scattoni V, Gallina A, Freschi M, De Almeyda EP, Girolamo VD, Montorsi F, Rigatti P. Are you the author?
Reference: BJU Int. 2011 Aug 22. Epub ahead of print.