Prostate biopsy outcome using 29 mm cutting length.

OBJECTIVES

The aim of the study was to compare the prostate biopsy outcome by using either standard or extended cutting length of the needles.

MATERIAL AND METHODS

A total of 74 consecutive prostates from radical prostatectomy were used. Two sextant biopsies were performed ex vivo. We developed a precise simulation of a transrectal biopsy procedure using ultrasound for guiding the needle. In the first set of biopsies an 18-gauge tru cut needle with 19 mm cutting length, powered by a automatic biopsy gun was used. In the second set a single use gun with an 18-gauge end-cutting needle and 29 mm cutting length was used.

RESULTS

In the set of sextant biopsies using 19 mm cutting length 49 (66%) carcinomas were found. In the set of sextant biopsies using 29 mm cutting length 58 (78%) of the tumors were detected. 24 (32%) prostates showed tumor in the transition zones, but there was no transition-zone-only cancer in this study. Nevertheless taking longer cores led to an improvement in prostate cancer detection of 18%.

CONCLUSIONS

In this ex vivo setting the use of 29 mm cutting length for prostate biopsy led to an significant improvement in cancer detection. As we found the end-cutting needle not suitable for use in the patient, these results support the idea to develop a longer tru cut needle and corresponding gun for further clinical investigations.