Standards for Prostate Biopsy
Prostate cancer is the most commonly diagnosed cancer amongst men. It is estimated that over 2 million biopsies are performed annually.1 Because the prostate’s anatomical location lends itself well to the transrectal pathway, it has remained the favoured route for decades.1 Typically, an abnormal digital rectal exam and/or elevated PSA level is a one way ticket to a systematic transrectal biopsy. Guided by ultrasound imaging, 10-12 random samples are taken using a hollow needle. Since the appearance of cancer on ultrasound imaging is pretty ambiguous, this method is considered “blind” as doctors try to sample the prostate in a systematic way.2 Currently the 10-12 core systematic transrectal biopsy is the standard for detecting prostate cancer (PCa), despite the fact that this method underestimates PCa incidence with a high false negative rate of up to 49%.3 Magnetic resonance imaging (MRI) offers an alternative diagnostic pathway in men with a clinical suspicion of cancer. Due to its superiority in differentiating between cancerous and normal tissue, the use of MRI as a triage test can not only improve detection rates of clinically significant cancer, but also prevent unnecessary biopsies.2 Whether systematic or MRI-targeted, biopsies may be performed via transrectal or transperineal approaches.1
The Transrectal Approach
The transrectal approach is favoured amongst doctors for its convenience, short learning curve and low cost. A systematic freehand transrectal biopsy (Fig 1.) may be performed in-office in as little as 10 minutes. Because the procedure is often done under local anaesthesia, this eliminates the need for specialized staff, a dedicated operating room and specialized equipment.1 Transrectal biopsies are considered a “dirty” procedure because the needle passes through the rectal wall, where each pass poses a risk to inoculate the prostate with rectal bacteria. To prevent infection, an enema and prophylactics, typically fluoroquinolonesFluoroquinolones are a type of carbapenem which is a highly effective class of antibiotics typically used to treat resistant bacterial strains.4, are administered prior to biopsy.1 However, fluoroquinolones have a major drawback in that its routine use may be developing the growth of antibiotic resistant bacteria and therefore making prophylactics less effective.1 Advances in MRI-targeted biopsy have addressed the issue of inaccuracy and a high false negative rate, but there is still concern for potential complications like rectal bleeding, fever, sepsis, hematuria and acute urinary retention.3
The Transperineal Approach
“The rate of sepsis post-transperineal biopsy is nearly 0%, which is 40 to 70 times less than that of transrectal.”5
The Fusion Bx: A Transrectal and Transperineal Solution
Focal Healthcare’s Fusion Bx is a simple prostate biopsy solution that supports both transrectal and transperineal approaches. The semi-robotic arm offers unrestricted freedom of motion, while our patented counterbalance technology keeps the probe steady in any position. The stepper unit features a removable cradle which can be changed to accommodate transrectal end-fire, side-fire and bi-plane (or linear) probes from various manufacturers. The simplified 4-step workflow can be easily advanced through using buttons on the stepper, which enables physicians to perform most of the procedure without having to take their hands off the probe. The software also provides a motion compensation feature that automatically adjusts for patient movement, which maintains MRI-US coupling, so the procedure may continue uninterrupted. In combination with the arm, stepper and software, physicians can seamlessly transition between either approach since the setup and workflow are the same in both cases. Using a system such as the Fusion Bx, reduces the need for a stabilizer and stepper, as these functions are already incorporated into its semi-robotic arm. This eliminates the inconvenience of not only purchasing the specialized software and hardware, but also time spent setting up or taking down the equipment for transperineal biopsies. Until transperineal is standard, clinics and hospitals can use the Fusion Bx for MRI-US fusion transrectal biopsies today and make the switch later on at no additional cost. For more information download our brochure or contact us at firstname.lastname@example.org.
1 Grummet, J., Pepdjonovic, L., Huang, S., Anderson, E., & Hadaschik, B. (2017). Transperineal vs. transrectal biopsy in MRI targeting. Translational Andrology and Urology, 6(3), 368–375. doi: 10.21037/tau.2017.03.58
2 Kasivisvanathan, Veeru, et al. MRI-Targeted or Standard Biopsy for Prostate-Cancer Diagnosis. New England Journal of Medicine. 2018; 378(19):1767–77. doi:10.1056/nejmoa1801993.
3 Xiang, J., Yan, H., Li, J., Wang, X., Chen, H., & Zheng, X. (2019). Transperineal versus transrectal prostate biopsy in the diagnosis of prostate cancer: a systematic review and meta-analysis. World Journal of Surgical Oncology, 17(1). doi: 10.1186/s12957-019-1573-0
4 Zowawi, H. M., Harris, P. N. A., Roberts, M. J., Tambyah, P. A., Schembri, M. A., Pezzani, M. D., … Paterson, D. L. (2015). The emerging threat of multidrug-resistant Gram-negative bacteria in urology. Nature Reviews Urology, 12(10), 570–584. doi: 10.1038/nrurol.2015.199
5 Grummet, J. P., Weerakoon, M., Huang, S., Lawrentschuk, N., Frydenberg, M., Moon, D. A., … Murphy, D. (2014). Sepsis and ‘superbugs’: should we favour the transperineal over the transrectal approach for prostate biopsy?. BJU International, 114(3). doi: 10.1111/bju.12536
6 Patel, P. (2020, February). The case for transperineal prostate biopsy vs. the transrectal approach. Urology Times, 48(2), 16–17.