The transperineal template biopsy (TPB) uses a biplanar ultrasound transducer mounted on a stand with a brachytherapy template grid. This helps to take multiple cores from all areas of the prostate in a systematic manner.
It avoids missing samples from the anterior and transition zones, the areas which contribute from a fourth to a half of all prostate cancer foci (which are also often missed by conventional TRUS biopsies). Nevertheless, this procedure also comes with potential side-effects.
Anesthetic complications and pain in the perineal region
As already mentioned, template biopsy involves multiple biopsy cores taken at the points of the brachytherapy template. This is a relatively painful procedure, and is routinely done under general anesthesia which can create its own risks, including cardiac arrest and respiratory difficulties.
However, the risk is low, and is usually not considered significant in view of the better accuracy of disease detection. In addition, nerve blocks and local anesthesia are also coming into use in the performance of template prostate biopsies.
Younger patients reported a higher incidence of pain in the perineal area after a template biopsy is performed, irrespective of the number of biopsies taken. Pain during the passing of urine is reported to occur in approximately 16% of patients. Moreover, perineal hematomas were observed in 13% of patients after the procedure.
Hematuria and hemospermia
The appearance of blood in urine is the most common side effect following a template biopsy of the prostate, and is reported to occur in about a half of all patients. Major hematuria occurred in only 6% of patients. Frank hematuria or persistent passage of blood during urination should be reported to the doctor promptly.
About 16% of patients observe blood in their semen during ejaculation after the procedure. This complication may persist for up to 6 weeks, but should be reported if it still has not stopped by then.
Retention of urine
As with other prostate biopsies, urinary retention may follow template biopsies of the prostate. They are reported in 6-7% of patients. Prophylactic administration of tamsulosin, an alpha-receptor blocker, may reduce spasm and facilitate reduction of retention rates.
Acute retention of urine may occur due to the bruising of the urethral or bladder wall by accidental needle perforation. This may lead to edema of the site, resulting in obstruction to the flow of urine.
In general, prostate biopsies are associated with a risk of infection of about 5%. However, this risk is significantly reduced, and may even be described as negligible, in transperineal biopsies. This is because it does not involve the passage of the needle through the rectum, avoiding in turn the transference of bacteria from this contaminated region to the prostate. Fever is reported to occur in about 3% of cases.
Learning curve and increased expense
Urologists need to learn the technique of using the template grid to take biopsies at the selected points. This may lead to a longer training period before the biopsy can be taken accurately.
Finally, template biopsies of the prostate require the use of general anesthesia and all the specialized equipment it entails, as well as a brachytherapy grid, and other equipment required to use the biplanar ultrasound imaging device and biopsy devices. This must be balanced against the increasing rates of hospital admission for sepsis-related complications following TRUS prostate biopsy, especially with multi-drug resistant organisms.
Reviewed by: Dr Tomislav Meštrović, MD, PhD