Prostate biopsy: a change of approach
DESPITE significant advances in prostate imaging in recent years, notably the emergence of multiparametric magnetic resonance imaging (MRI) and molecular imaging, biopsy remains central to prostate cancer diagnosis. Over 2 million prostate biopsies are performed annually worldwide, and these are performed via the transrectal or transperineal route.
Traditional transrectal ultrasound-guided prostate biopsies (TRUSB) involve an ultrasound probe attached to a biopsy needle being inserted into the rectum. The needle then passes through the rectum to target the prostate, rendering the procedure unsterile. Hence, TRUSB requires broad spectrum antibiotics to reduce the risk of sepsis, which may be life-threatening. Indeed, the rate of TRUSB-related sepsis has been increasing. Nam and colleagues noted rising rates of TRUSB-related sepsis hospitalisations, from 0.6% in 1996 to 3.5% in 2005, in a retrospective study of patients who underwent TRUSB in Canada. TRUSB sepsis rates typically vary between 1% and 5%, but can be as high as 17.5%.
Another issue with TRUSB is the need for broad spectrum antibiotic prophylaxis, which is promoting the emergence of antibiotic-resistant organisms (here, and here). Fluoroquinolones are typically used but there is increasing concern about the association between fluoroquinolones and potentially serious adverse effects such as diarrhoea, vomiting, tendinopathies, myopathies, central nervous system disturbances, retinal detachment and aortic aneurysms. Indeed, the European Association of Urology has recently advised that these antibiotics should no longer be used as prophylaxis in TRUSB.
Not only is fluoroquinolone use in itself a concern, but if broader spectrum antibiotics (eg, carbapenems) are being used instead, then this increases the prevalence of extended-spectrum beta-lactamase and other resistant bacteria. Really, it is only a matter of time before resistance to these last lines of antibiotics emerges.
Fortunately, there is an alternative to transrectal biopsy.
Transperineal prostate biopsies (TPB) also involve inserting an ultrasound probe into the rectum to visualise the prostate, but the biopsy needle instead passes through the skin of the perineum to target the prostate. The perineal skin can be cleaned with topical agents, enabling a sterile procedure. TPB has much lower infection and sepsis rates, even without using antibiotic prophylaxis. Vyas and colleagues and Pepe and colleagues report a 0% sepsis rate in their TPB series of 634 and 3000 patients, respectively. Other studies, such as Baba and colleagues, report a very low sepsis rate of 0.82% in a retrospective series of 495 patients who underwent TPB.
Not only does TPB offer a significantly lower rate of infection, but there is some evidence that it has improved cancer detection rates of tumours in the anterior prostate, compared to TRUSB (here, here, and here). Hence, a move towards TPB is much needed.
Regrettably, there has been resistance towards a move to TPB. In 2017, TRUSB remained the most popular method of prostate biopsy in Australia and New Zealand, with 50% of biopsies being performed via the rectal route. The main deterrent has been that TPB is traditionally performed under general anaesthesia (GA), as it involves multiple needles traversing the perineum. It therefore carries the risks associated with GA is associated with increased cost, and requires access to operating theatres. However, a promising trend has emerged over the last few years; with the proportion of TRUSB decreasing by up to 13%, and the proportion of TPB conversely increasing.
This trend has, in part, been propelled by the development of transperineal access systems (TAS), such as PrecisionPoint (Perineologic, Cumberland, US), which enable free-handed TPB to be performed via two skin punctures under local anaesthetic (LA) in the outpatient setting. Several studies have described feasibility and success in sampling the prostate under LA, and the potential to reduce costs. The ability to perform TPB under LA, using a TAS promises to be the catalyst for “TRexit” – the process of switching from TRUSB to TPB.
Our department at Fiona Stanley Hospital in Perth, Western Australia has successfully completed “TRexit”, wherein transrectal biopsy is no longer performed. Moreover, the majority of our TPB are being performed under LA in the outpatient setting. Only obese patients and those who decline the procedure under LA, undergo GA TPB. “TRexit” at our hospital followed a step-wise implementation process.
Dr Matthew Brown visited Guy’s Hospital in the UK over a 2-week period to undergo training with Dr Rick Popert, a leading urologist senior and author on one of the aforementioned studies assessing the efficacy of LA TPB via the PrecisionPoint TAS. Dr Brown then returned to FSH and performed the first nine TPB cases under GA or spinal anaesthesia, while the next 14 were performed under sedation in order to facilitate familiarity with the technique and LA protocol. Subsequent cases were done under LA. Other consultants in our department were subsequently trained to perform TPB under LA. We are currently auditing our results and patient reported outcomes.
In our view, the next steps in prostate cancer diagnosis in Australia would be to improve access to TPB. More urologists should be trained to perform TPB under LA in the outpatient setting to enable the transition away from TRUSB. Moreover, nurse practitioners could also be trained to perform this procedure, further improving access to the service. Nurse practitioners have been performing TPB in UK centres for many years, with studies demonstrating that these nurses can perform TPB safely and effectively.
We hope that there will be ongoing improvements in the uptake of TPB and the phasing out of TRUSB in the years to come. Men deserve a sterile and safer approach to prostate cancer diagnosis.
Dr Matt Brown is a urological surgeon and Head of Robotic Surgery at Fiona Stanley Hospital and a founding partner in Perth Urology Clinic, Western Australia’s largest private urology practice.
Dr Pravin Viswambaram is a urology registrar at Fiona Stanley Hospital in Perth, and is also affiliated with the University of Western Australia’s School of Medicine and ANZUP.
The statements or opinions expressed in this article reflect the views of the authors and do not represent the official policy of the AMA, the MJA or InSight+ unless so stated.