A prostate biopsy is a medical procedure used to confirm the presence of prostate cancer. The procedure is typically recommended when initial screening tests, such as a Prostate-Specific Antigen (PSA) blood test, show elevated levels, or if a Digital Rectal Exam (DRE) reveals abnormal findings. During the biopsy, a physician takes small tissue samples, or cores, from the prostate gland to be examined under a microscope. This is the only definitive method for diagnosing prostate cancer and determining how aggressive any detected cancer may be.
Preparing for the Biopsy
Patients must temporarily stop taking medications that can increase the risk of bleeding, such as aspirin, warfarin, and non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen. The specific duration for stopping these blood thinners depends on the medication, but it is typically several days and requires clearance from the prescribing physician.
Prophylactic antibiotics are taken shortly before and sometimes after the procedure to minimize the risk of infection. Because one common biopsy method involves passing a needle near the rectum, infection is a potential complication. Patients are also usually instructed to perform a bowel preparation, such as a cleansing enema, at home a few hours before the appointment to clear the rectum.
Understanding the Procedure Methods
Physicians primarily use one of two methods to access the prostate for tissue sampling, both of which use ultrasound imaging for guidance. The traditional approach is the Transrectal Ultrasound-Guided (TRUS) biopsy, where the needle passes through the wall of the rectum to reach the prostate. This method is often performed with local anesthesia in an outpatient setting.
A newer technique, the Transperineal biopsy, involves inserting the needle through the skin of the perineum, the area between the scrotum and the anus. The advantage of the transperineal route is a significantly lower risk of post-biopsy infection, as the needle avoids passing through the bacteria-rich rectal wall. While the TRUS approach has an infection rate that can be a few percent, the transperineal method’s infection rate is often less than one percent.
Both methods often utilize advanced imaging techniques, such as fusing real-time ultrasound images with a Magnetic Resonance Imaging (MRI) scan of the prostate. This MRI-fusion guidance allows the physician to target suspicious areas identified on the scan, which improves the accuracy of the biopsy compared to systematic sampling alone. The choice between TRUS and Transperineal depends on the patient’s individual risk factors, the physician’s expertise, and whether the procedure is performed in an office or a hospital setting.
Step-by-Step Tissue Sampling
The process of tissue sampling begins after the patient is positioned, typically lying on their side with knees drawn toward the chest, and the area is cleaned. A lubricated ultrasound probe is inserted into the rectum to generate real-time images of the prostate. This imaging guides the entire procedure, allowing the physician to visualize the gland and the path of the biopsy needle.
Local anesthesia is injected to numb the tissue around the prostate, minimizing discomfort during the core collection. Once the target areas are identified, the physician uses a spring-loaded biopsy device to rapidly retrieve the tissue samples. This device makes a “click” sound each time it fires a thin, hollow needle into the prostate and snaps back, capturing a cylindrical piece of tissue.
A systematic approach is followed, where the physician collects a standard number of cores, usually between 10 and 12, from different zones of the prostate. If an MRI-fusion technique is being used, additional targeted cores are taken from any suspicious areas. Immediately upon retrieval, each core is placed into separate, labeled containers filled with a preservative solution for the pathology laboratory.
Post-Procedure Care and Core Analysis
Following the procedure, patients are monitored briefly and given instructions for at-home care before being discharged. It is common for men to notice blood in their urine or stool for a few days, and blood in the semen, which appears as a rusty or dark color, can persist for several weeks or even months. Mild discomfort or pain in the biopsy area is normal and usually managed with over-the-counter pain relievers like acetaminophen.
Patients must be alert for signs of infection, which remains the most significant risk, especially with the TRUS method. A fever above 101°F, excessive bright red bleeding, or an inability to urinate are symptoms that require immediate medical attention. The collected cores are sent to a pathology lab where a specialist examines the tissue under a microscope.
The pathologist determines if cancer cells are present, and if so, assigns a grade based on how abnormal the cell patterns appear, which is known as the Gleason Grade. These grades are combined to produce a Gleason Score, typically ranging from 6 to 10, which indicates the aggressiveness of the cancer. The pathology report detailing the score and other findings is used by the urologist to discuss diagnosis and potential treatment options.