A prostate biopsy is a medical procedure performed to obtain small tissue samples from the prostate gland. These samples are then examined under a microscope to detect the presence of prostate cancer or other abnormal cells. When a healthcare provider suspects prostate cancer based on initial tests, a biopsy becomes a necessary step for an accurate diagnosis. Different approaches exist for performing this biopsy, with two common methods being the transrectal and transperineal techniques.
Transrectal Prostate Biopsy Explained
The transrectal prostate biopsy, often guided by transrectal ultrasound (TRUS), involves inserting an ultrasound probe into the rectum to visualize the prostate gland. Local anesthesia is administered around the prostate to minimize discomfort.
A fine biopsy needle is then guided through the rectal wall and into the prostate gland. The needle collects small tissue samples from various areas of the prostate. The entire procedure usually takes between 15 to 30 minutes.
Transperineal Prostate Biopsy Explained
The transperineal prostate biopsy involves accessing the prostate through the perineum, the skin area between the scrotum and the anus. It typically uses ultrasound guidance, sometimes combined with MRI images, to precisely direct the biopsy needle.
Local anesthesia is injected into the perineum. The biopsy needle is then inserted through the numbed skin of the perineum and into the prostate. This approach allows for tissue samples to be taken from various parts of the prostate, including hard-to-reach regions. The procedure can last between 20 to 45 minutes.
Key Differences in Patient Experience
The patient experience varies between the transrectal and transperineal biopsy methods. Transrectal biopsies are commonly performed with local anesthesia. Patients may feel mild pain or pressure when the needle enters the prostate.
For transperineal biopsies, local anesthesia is also standard, but some patients may opt for sedation or general anesthesia. While the transperineal route avoids passing through the rectal wall, it may be associated with greater initial discomfort during the local anesthetic injection.
Mild discomfort and some bleeding are common following either procedure. With transrectal biopsies, patients may experience rectal bleeding for a few days, and blood in urine or semen for several days to weeks. Recovery from a transrectal biopsy involves resuming normal activities within one or two days.
Transperineal biopsies can result in blood in the urine for a few days and blood in the semen for several weeks. Bruising or discomfort in the scrotum or perineum may also occur. Patients are advised to avoid strenuous activity for 24-48 hours after either biopsy.
Comparing Diagnostic Effectiveness and Safety
The diagnostic effectiveness and safety of transrectal and transperineal prostate biopsies differ. The transperineal approach may offer superior detection of tumors located in the anterior (front) part of the prostate, which are less accessible via the transrectal route. Some studies show a higher overall detection rate for clinically significant prostate cancer with transperineal biopsy. However, other studies suggest similar overall cancer detection rates between the two methods, particularly with MRI-targeted biopsies.
A notable difference in safety lies in the risk of infection. Because the transrectal biopsy needle passes through the rectal wall, it carries a risk of introducing bacteria into the prostate and bloodstream, potentially leading to infections like sepsis. The risk of sepsis following transrectal biopsy is higher compared to transperineal biopsies. In contrast, the transperineal approach, by avoiding the rectum, presents a lower risk of infection.
Other complications, such as bleeding and urinary retention, can occur with both procedures. Blood in the urine and semen are common after both biopsy types, often resolving within days to weeks. Rectal bleeding is primarily associated with the transrectal method. Urinary retention is a less common complication that can occur with both methods.
Factors Guiding Method Selection
The choice between a transrectal and transperineal prostate biopsy is a personalized decision made in consultation with a healthcare provider. Imaging findings, particularly from multiparametric MRI (mpMRI), play a significant role. If an MRI identifies suspicious lesions primarily in the anterior or apical regions of the prostate, a transperineal biopsy may be preferred due to its better access to these areas.
A patient’s medical history is also considered. Individuals with previous negative transrectal biopsies but continued suspicion of cancer, or those on active surveillance requiring repeat biopsies, might be advised to undergo a transperineal procedure. This is relevant if there are concerns about antibiotic resistance from prior transrectal procedures. Patient preference and anxiety levels also factor into the decision, as the transperineal approach can sometimes be performed under deeper sedation or general anesthesia. The urologist’s expertise and available equipment also guide the selection.