A new way to avoid post-biopsy infections

By Russell Rian

Adding another antibiotic to the recommended antibiotic cocktail for prostate biopsies significantly reduced hospitalizations after the procedure and proved cost-effective, a study by UT Southwestern Medical Center urologists shows.

Dr. Yair Lotan
Dr. Yair Lotan

Infections after prostate biopsies, a common procedure performed to determine whether prostate cancer exists, have been rising nationally for several years. UT Southwestern urologists switched tactics to determine whether the additional antibiotic – gentamicin – would help stem the increase. They found it did.

Their two-year clinical investigation, published recently in The Journal of Urology, demonstrated a sixfold drop in post-procedural infection rates. Although limited to a single health care institution, the study addresses an area of significant clinical concern and cost.

“An increase in resistance happens with every antibiotic over time,” said Dr. Yair Lotan, Professor of Urology and senior author of the study. “We noticed that the traditional antibiotics were not working quite as well, and we’d had an increase in infections. Based on that, we changed our practice. We were extremely pleased to see these results.”

Infectious complications generally occur in 1 percent to 6 percent of patients undergoing the procedure, called transrectal ultrasound-guided prostate biopsy (TRUSBx). Symptoms can range from fever and urinary tract infections to more serious complications, such as sepsis.

Nationally, studies had begun tracking the rise in infections due to antibiotic resistance of quinolone, the traditionally recommended antibiotic. In their study, UT Southwestern researchers found that 73 percent of patients admitted with post-biopsy infection who received the standard antibiotic protocol had fluoroquinolone-resistant E. coli urinary infection and/or bacteremia, while only 9 percent had strains resistant to gentamicin.

The study compared results at UT Southwestern’s outpatient clinic in 2010 and 2011 and found that hospitalizations dropped from 3.8 percent to 0.6 percent after physicians added gentamicin to the typical antibiotic standard of care. In addition, the augmented regimen’s low infection rate resulted in an overall cost savings of $145 per patient compared with the standard regimen.

Roughly 1.5 million prostate biopsies are performed annually in the U.S., so the results potentially have large implications, Dr. Lotan noted. When prostate-specific antigen (PSA) or digital rectal exam (DRE) test results are abnormal, biopsies are commonly ordered to find or diagnose prostate cancer. More than 238,000 new cases of prostate cancer are expected to be diagnosed in the U.S. this year, with more than 29,000 deaths, according to the National Cancer Institute. 

Other UT Southwestern researchers participating in the study were lead author Dr. Mehrad Adibi, a Urology resident; Dr. Brad Hornberger, faculty associate in Urology; Deepa Bhat, senior Qi analyst; Dr. Ganesh Raj, Associate Professor of Urology; and Dr. Claus G. Roehrborn, Chair of Urology.

Dr. Lotan holds the Helen J. and Robert S. Strauss Professorship in Urology.

Dr. Roehrborn holds the E.E. Fogelson and Greer Garson Fogelson Distinguished Chair in Urology, and the S.T. Harris Family Chair in Medical Science, in Honor of John D. McConnell, M.D.

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