Targeted Prostate Biopsy: What to Expect During the Procedure

A targeted prostate biopsy uses images from a previous MRI scan to guide a needle directly into suspicious areas of the prostate, rather than sampling the gland at random. The procedure itself usually takes between 15 and 30 minutes, involves local or sometimes general anesthesia, and is performed either through the rectum or through the skin between the scrotum and anus. Compared with older “blind” biopsy methods, this approach catches more aggressive cancers and flags fewer harmless ones, but the experience for you as a patient still involves preparation steps, real-time imaging, multiple needle passes, and a short recovery window that are worth understanding in advance.

Why an MRI Comes First

Before a targeted biopsy can happen, you need a multiparametric MRI of the prostate. This scan combines several imaging sequences to build a detailed picture of the gland’s anatomy and highlight areas that look abnormal. Over the past decade, multiparametric MRI has become the primary imaging tool for detecting, localizing, and staging prostate cancer.¹ The scan typically includes T2-weighted imaging, diffusion-weighted imaging, and dynamic contrast-enhanced imaging, each contributing different information about tissue density, water movement, and blood flow.²

A radiologist reviews the images and scores each suspicious area on a scale called PI-RADS, which runs from 1 (very unlikely to be cancer) to 5 (very likely to be cancer). That score determines whether a biopsy is recommended and, if so, how aggressively the suspicious spot should be sampled. A PI-RADS 3 lesion sits in a gray zone, while PI-RADS 4 and 5 lesions carry enough suspicion to strongly warrant tissue sampling. Not every MRI finding turns out to be cancer. In one study of patients with PI-RADS 4 and 5 lesions who underwent transperineal biopsy, about 20% came back negative, and on follow-up review, many of those had been overestimated on imaging, particularly when benign nodules in the transition zone mimicked cancerous tissue.³

How the Targeting Actually Works

The word “targeted” can mean a few different things in practice. The common thread is that MRI images taken days or weeks before the biopsy are used to guide the biopsy needle to specific spots rather than sampling the prostate blindly. There are two main approaches.⁴

With cognitive fusion, the urologist mentally maps the MRI findings onto the live ultrasound image during the biopsy. The doctor looks at the MRI on a screen, identifies the suspicious area, then uses their spatial reasoning to aim the needle at the corresponding location on the ultrasound. This relies on the operator’s experience and judgment.

With software fusion, a computer overlays the MRI onto the real-time ultrasound, aligning the two images so the suspicious lesion is highlighted directly on the screen the urologist is watching during the biopsy. This takes some of the guesswork out of spatial matching. A third, less common option is in-bore MRI-guided biopsy, where the entire procedure is done inside the MRI scanner itself, though this is slower and less widely available.

Research comparing these methods shows that no single targeting approach catches everything on its own. In one prospective study, using either cognitive or software fusion alone missed between roughly 12% and 33% of clinically significant cancers that were found when all methods were combined.⁵ This is why many centers now perform targeted biopsy alongside a systematic sampling of the rest of the gland.

Transrectal Versus Transperineal Routes

The biopsy needle can reach your prostate from two directions. The transrectal approach passes the needle through the wall of the rectum, guided by an ultrasound probe inserted into the rectum. This has historically been the more common route and is typically done under local anesthesia in an office or outpatient setting.

The transperineal approach passes the needle through the perineum, the patch of skin between the scrotum and anus. The patient lies in a position with legs supported (similar to a gynecological exam position), and the needle is guided through the skin under ultrasound guidance. This can be done freehand or through a template grid, with various fusion techniques available for targeting MRI-identified lesions.⁶ Transperineal biopsy has traditionally been performed under general anesthesia, though many centers now use local anesthesia to avoid the added cost and recovery time of sedation.

The main practical difference between routes comes down to infection risk. Because the transrectal route pushes a needle through the rectal wall, which is home to bacteria, there is a higher chance of infection, including serious bloodstream infections. Reported sepsis rates after transrectal biopsy range from about 0.4% to nearly 10%, compared with 0% to 1% for the transperineal route.⁷ This safety advantage has driven a noticeable shift toward the transperineal approach in recent years. In a randomized comparison, a combination of fever, antibiotic use, and emergency visits occurred in about 0.9% of transrectal patients versus 0.6% of transperineal patients, and overall fever rates were low in both groups at under 2%.⁸

What Pain Management Looks Like

The procedure involves a spring-loaded biopsy gun firing a thin needle into prostate tissue multiple times. That is not painless, but it is manageable with anesthesia. Local anesthesia has become the standard approach for both routes, offering targeted relief with minimal side effects.⁹

For transrectal biopsies, the most common technique is a periprostatic nerve block, where a local anesthetic is injected around the nerves at the base of the prostate. One study comparing three anesthesia methods found that periprostatic block produced the lowest average pain scores, significantly better than lidocaine gel alone or pudendal block.¹⁰ A large network meta-analysis of 47 trials found that combining a periprostatic nerve block with intravenous sedation was the most effective approach overall, but in an outpatient setting where sedation is impractical, periprostatic block with or without rectal lidocaine works well for most patients.¹¹

For transperineal biopsies, local anesthetic is injected into the perineal skin and surrounding tissue. Some centers still use general anesthesia or sedation for the transperineal route, particularly when a template grid is used and many cores are taken, but the trend is moving toward local-only protocols. You should expect a brief sting from the anesthetic injection, followed by a sensation of pressure or dull discomfort during each core. Most patients describe it as uncomfortable rather than severely painful.

What Happens During the Procedure Itself

Once the anesthesia is in place, the urologist inserts an ultrasound probe, either into the rectum or against the perineum, to visualize the prostate in real time. If software fusion is being used, the pre-biopsy MRI images are loaded into the system and registered to the live ultrasound, creating the overlay that highlights the target.

The doctor then advances the biopsy needle toward the first suspicious area and fires the spring-loaded device. You will hear a click and feel a brief jolt. Each firing extracts a thin core of tissue roughly the size of a short piece of spaghetti. The process repeats for each target. How many cores are taken from each lesion varies by center, but research has examined whether two, three, or four cores per target makes a difference. For the highest-suspicion lesions (PI-RADS 5), the detection rate is similar regardless of whether two, three, or four cores are taken. For moderate-suspicion lesions (PI-RADS 4), taking at least three cores per lesion appears to improve detection compared with just two.¹²

In practice, many urologists take at least four targeted cores per lesion, then perform an additional systematic biopsy of the rest of the gland, typically 12 more cores in a standardized pattern.¹³ That may sound like a lot of needle passes, but the targeted portion focuses tightly on a few spots, and the systematic sampling covers ground the MRI may have missed. The total number of cores across both methods often lands between 14 and 20.

Why Most Centers Still Add Systematic Cores

You might wonder why, if the MRI already identified the suspicious spots, your doctor would also sample areas that looked normal. The answer is that MRI misses some cancers, and targeted biopsy alone leaves gaps. A landmark trial found that MRI-targeted biopsy detected clinically significant cancer in 38% of men, compared with 26% for standard biopsy alone, a meaningful improvement.¹⁴ But the combined approach catches more than either method in isolation. In a large cohort of 960 men who had both, cancer was found in about 68% overall; targeted biopsy alone would have diagnosed about 51%, and systematic biopsy alone about 60%. In the men whose systematic biopsies were negative, targeted biopsy still picked up cancer in an additional 8%.¹⁵

A recent study comparing the two strategies confirmed that the combined approach detects more clinically significant cancer (about 62%) than either targeted (50%) or systematic (49%) biopsy on its own.¹⁶ The tradeoff is a few extra minutes on the table and slightly more cores, but for now, the evidence strongly favors doing both.

What to Expect Afterward

After the biopsy, you will likely be monitored briefly and then allowed to go home the same day. You should expect some blood in your urine for a day or two, and possibly some rectal bleeding if you had a transrectal biopsy. The most surprising aftereffect for many men is blood in the semen. In a prospective study following men after transrectal biopsy, 90% of those who were able to ejaculate experienced bloody semen, and the average duration was about four weeks.¹⁷ This is cosmetically alarming but medically harmless and resolves on its own.

Other common aftereffects include mild soreness at the biopsy site, temporary difficulty urinating, and occasionally some bruising of the perineum if you had a transperineal approach. Serious complications such as heavy bleeding requiring intervention, urinary retention, or infection severe enough to need hospitalization are uncommon but do occur. You should contact your doctor if you develop a fever, cannot urinate, or notice heavy bleeding that does not stop.

Beyond the physical side, it is worth acknowledging that the experience carries genuine psychological weight. Qualitative research with biopsy patients has consistently found that the procedure creates physical, psychological, and social stress, and that patient satisfaction is strongly influenced by trust in the medical team and clear, empathetic communication beforehand.¹⁸ Men who receive both targeted and systematic biopsies report higher anxiety and discomfort than those who receive systematic biopsy alone, likely because the procedure takes longer and involves more cores.¹⁹ If you are feeling anxious, that is entirely normal, and asking your urologist to walk you through each step before and during the procedure can help.

Understanding Your Results

Biopsy results typically come back within one to two weeks. If cancer is found, the pathologist assigns a Grade Group from 1 to 5, based on the microscopic appearance of the tissue. Grade Group 1 represents slow-growing cancer that may never need treatment. Grade Groups 4 and 5 indicate more aggressive disease. The scoring system was updated in 2014 to reduce ambiguity in the older Gleason score, which sometimes grouped very different cancers under the same number.²⁰

One thing to understand about biopsy results is that they are a sample, not a complete picture. The grade assigned on biopsy sometimes differs from the grade found later if the entire prostate is removed surgically. Recent research has highlighted that targeted biopsy alone carries a risk of downgrading at surgery, meaning the cancer may turn out to be slightly less aggressive than the biopsy suggested. This is particularly relevant for men with an initial Grade Group 4 finding. While this has minimal consequences for men facing treatment for high-risk disease, it raises concerns about overtreatment in men on the borderline of qualifying for active surveillance.²¹ This grading discrepancy is another reason combined biopsy remains the recommended approach: the targeted cores and systematic cores together give the pathologist a more complete picture of the tumor’s behavior.

When a Targeted Biopsy Might Be Avoided

Not everyone with an elevated PSA ends up needing a biopsy. In the MRI-first screening pathway being studied in large trials, men with a PSA of 3 or higher undergo an MRI, and only those with suspicious findings proceed to biopsy.²² If the MRI is clean, many men can avoid biopsy altogether, at least for the time being. This represents a significant shift from the older approach, where a PSA above a threshold automatically triggered a biopsy with a dozen or more random needle passes.

There are also men who have had a previous negative biopsy and are being monitored because their PSA remains elevated or is rising. For these men, a targeted biopsy guided by MRI can be especially valuable because it focuses on the specific areas the previous sampling may have missed, rather than repeating the same blind approach that already came back empty.

Cost and Access Realities

Adding MRI to the biopsy pathway means adding an imaging appointment and its associated cost, which raises fair questions about whether the approach is worth the extra expense. Economic analyses have consistently found that the MRI-then-targeted-biopsy strategy is cost-effective compared with jumping straight to standard biopsy. One U.S.-based analysis found it cost-effective across all PSA levels above 2.5, with the cost per quality-adjusted life-year gained ranging from roughly $6,000 to $21,000 depending on the PSA stratum, well under the commonly used willingness-to-pay threshold of $100,000.²³ A systematic review across multiple countries similarly found MRI with targeted biopsy to be cost-effective in both first-time and repeat-biopsy settings.²⁴

The practical barrier is access. Not every urology practice has a software fusion platform, and the quality of the prebiopsy MRI depends heavily on the experience of the radiologist reading it and the machine it was performed on. If you are at a community practice without fusion technology, cognitive fusion (the mental-overlay method) is still a valid option and has been shown to be cost-effective in the initial biopsy setting.²⁴ But it is worth asking your urologist whether they regularly perform targeted biopsies and what fusion method they use, because operator experience matters.

Where AI Fits Into Targeted Biopsy

Artificial intelligence is beginning to enter the targeted biopsy workflow, primarily at the MRI-reading stage. AI software can automatically segment the prostate gland, identify its anatomical zones, and highlight regions suspicious for clinically significant cancer, essentially doing some of the radiologist’s work before the biopsy even begins. One randomized trial tested an AI system that used a cascade of deep-learning models to classify MRI sequences, segment the prostate and its zones, and outline suspicious lesions, then fed that information into the cognitive fusion biopsy process.²⁵

The promise here is twofold. First, AI could help less experienced radiologists achieve readings on par with experts, which would help close the access gap mentioned above. Second, AI-generated prostate maps could make cognitive fusion more precise by giving the urologist a clearer, computer-annotated reference image to work from during the biopsy. This technology is still in early clinical testing, but it represents the direction the field is heading: making targeted biopsy more consistent and less dependent on the specific hospital or doctor you happen to visit.