Effect of needle size on cancer detection, pain, bleeding and infection in TRUS-guided prostate biopsies: a prospective trial

Abstract

Introduction: Transrectal ultrasound (TRUS)-guided prostate biopsies using 18G calibre needles are widely used; most often 12-core tissue samples of the peripheral zone are obtained. Although the diagnostic yield of prostate biopsies is fair, there is still a potential for false negative results, which necessitates repeat biopsies. In an effort to improve the accuracy of prostate biopsies, different sampling schemes have been developed. One strategy has been to increase the number of core biopsies performed on each patient. Another strategy has been to improve the reliability of prostate biopsies using larger calibre needles, thereby increasing the amount of tissue obtained for each core biopsy. Methods: After approval by our institutional review board, we prospectively compared two biopsy needle sizes (18G vs. 16G) in relation to prostate cancer diagnosis, pain, bleeding and infection rates on 105 patients. Each patient underwent 6 TRUS-guided prostate biopsies with the standard 18G needle and 6 other biopsies with the experimental 16G needle. To evaluate possible complications related to the use of a larger 16G needle in the experimental group, we compared pain, bleeding and infection rates with a control group of 100 patients who underwent 12 biopsies with a single 18G needle (18G group). Pain, bleeding assessment and infection events were evaluated using patient questionnaires and telephone interviews. Results: TRUS-guided prostate biopsies using 16G calibre needles did not increase cancer detection or non-malignant pathology rate, including prostatic intraepithelial neoplasia (PIN) and atypical small acinar proliferatio (ASAP). Pain, bleeding and infectious complications were similar in both groups. Infection was defined as temperature above 38°C occurring within 48 hours after the procedure. We identified 4 patients with post-biopsy fever in the experimental (16/18G) group and 4 other patients in the (18G) control group. The post-biopsy infection rate is higher than reported just a few years ago and indicates that quinolone resistant Escherichia coli seems to be more prevalent in our urban setting than previously suspected. Limitations to our study include small group numbers. Conclusion: Larger 16G needles appear to be safe for TRUS-guided prostate biopsies. Further study in a larger, multi-institutional, prospective, randomized manner with 16G needles is warranted to assess the theoretical benefit of larger core biopsies in prostate cancer detection.

Prevalence of fluoroquinolone‐resistant rectal flora in patients undergoing transrectal ultrasound‐guided prostate needle biopsy: A prospective multicenter study

“…26 Using a smaller needle size also showed no definite advantages in pain, bleeding, and infectious complications. 27 Washing the prostate biopsy needle with povidone-iodine has shown no reduction in infectious complication rates. 28 As previously reported, the most common risk factor of postbiopsy infectious complication is previous antibiotics exposure.…”

“…Rectal cleansing with povidone‐iodine or chlorhexidine has been studied, but the results are currently inconclusive . Using a smaller needle size also showed no definite advantages in pain, bleeding, and infectious complications . Washing the prostate biopsy needle with povidone‐iodine has shown no reduction in infectious complication rates …”

Guidelines for Transrectal Ultrasonography-Guided Prostate Biopsy: Korean Society of Urogenital Radiology Consensus Statement for Patient Preparation, Standard Technique, and Biopsy-Related Pain Management

“…The size of the biopsy needle is usually 18-gauge, and there are studies reporting that an increase in the size of the core to a 16-gauge does not cause any side effects or differences in CDR (32). The length of the core has a great effect on the CDR (32,33), and one study recommended that the length of the core be greater than 11.9 mm (33). Therefore, there could be no significant difference in CDR between the 16-mm and 22-mm biopsy needles.…”

Complications and Prostate Cancer Diagnosis Rate of TRUS Prostate Biopsies Using 16 and 18G Needles by Clavien Scoring

“…McCormack et al (19) conducted a prospective study in which 105 patients were included and assessed two groups in terms of 16G and 18G needles detecting prostate cancer, pain, bleeding, and infection rates and reported that there were no significant differences. Again, in another study that compared the 18G and 20G biopsy needles, no differences were determined in terms of detecting cancer, and the complication rates were lower when a 20G needle was used (20).…”