MRI-fusion transperineal prostate biopsy

A test that takes small samples of the prostate with a thin needle passed through the skin between the scrotum and the anus, guided by ultrasound and usually by an MRI map, to look for prostate cancer.

Also called TP biopsy, TPB, Transperineal prostate biopsy, MRI fusion biopsy, MRI-targeted prostate biopsy, Fusion biopsy, Targeted biopsy, Template biopsy

Where: Clinic procedure room, or an outpatient surgery center
Anesthesia: Local numbing, sometimes with light sedation; or general anesthesia in an operating room
Time in the room: About 20 to 45 minutes
Hospital stay: Same day
Back to normal: 1 to 2 days
Back to work: Next day for most people

See the steps

ProstatePerineumRectumBladderUrethra

Where it happens. The highlighted part is what this procedure treats.

Overview

A prostate biopsy is the only way to confirm prostate cancer. It removes about 12 to 20 thin cores of tissue, each about as wide as a pencil lead and up to about an inch long, for a pathologist to examine under a microscope.

In a transperineal biopsy, the needle goes through the skin of the perineum, the area between the scrotum and the anus. An ultrasound probe in the rectum makes the pictures, but the needle does not pass through the rectum. Because of this, the risk of serious infection is very low, and many centers give no antibiotics or only a single dose.

Most biopsies today are guided by an MRI done beforehand. Software lays the MRI map of any suspicious area over the live ultrasound picture, which is called fusion, so the needle can aim right at it. Most teams also take samples from the rest of the prostate in a set pattern.

It can be done awake in a clinic with numbing medicine, or asleep in an operating room. Results usually take about 5 to 10 days.

The parts of your body involved

The prostate sits below the bladder and just in front of the rectum. Below it is the perineum, the skin and muscle between the scrotum and anus. From the perineum, a needle can reach every part of the prostate, including the front and the lowest tip, which are harder to reach from the rectum.

Prostate
A walnut-sized gland under the bladder. Cancer most often starts in its back and outer part, but it can grow anywhere in the gland.
Perineum
The area of skin and muscle between the scrotum and the anus, where the needle enters.
Rectum
The last part of the bowel, just behind the prostate. The ultrasound probe sits here to make pictures.
Urethra
The tube that carries urine from the bladder through the middle of the prostate and out through the penis.
MRI target
An area that looked suspicious on MRI, scored from 1 to 5 on a scale called PI-RADS. Higher scores are more likely to be cancer.

Why it’s done

A biopsy is recommended when your PSA, MRI or exam suggests a cancer that matters may be present, or to recheck a known cancer. The transperineal route is chosen for its very low infection risk and good access to all parts of the prostate.

A raised or rising PSA
PSA is a blood test. A high or climbing level can come from cancer, but also from an enlarged prostate or inflammation. A biopsy tells them apart.
A suspicious MRI
A PI-RADS score of 4 or 5 means a significant cancer is likely. A score of 3 is in between, and your urologist weighs it with your PSA, prostate size and other tests.
An abnormal exam
A hard area or lump felt during the finger exam of the prostate.
Checking a known cancer
Men on active surveillance have repeat biopsies to make sure a low-risk cancer has not changed.
Lower infection risk
Because the needle does not cross the rectum, serious infections are rare, which is why European guidelines prefer this route and many U.S. centers now use it.

Other options

Transrectal biopsy
The needle passes through the wall of the rectum instead. It is quick and widely available and finds cancer at similar rates, but carries a higher risk of infection and needs antibiotics.
Repeat PSA and watch
If the PSA rise is small or the MRI looks normal, repeating the PSA in a few months may be reasonable.
Blood or urine marker tests
Additional tests on blood or urine can help estimate the chance of a significant cancer and may help some men avoid a biopsy.
MRI first, then decide
If you have not had an MRI, guidelines support doing one before a first biopsy when available. A normal MRI with low PSA density may mean a biopsy can wait.

Getting ready

Tick items off as you go. Your checklist is saved on this device only.

1 to 2 weeks before

MRI

You usually have a prostate MRI first, so the biopsy can target any suspicious areas.

Blood thinners

Tell your team about any blood thinner. Many men continue low-dose aspirin. Others, such as clopidogrel, warfarin or apixaban, may be paused for a few days. Never stop one on your own.

Urine test

A urine test may be done to make sure you do not have an infection.

Allergies

Tell your team about allergies to numbing medicines, antibiotics or latex.

The day before

Arrange a ride if you will have sedation

If you are having sedation or anesthesia, someone must drive you home and ideally stay with you that evening.

Eating and drinking

For a biopsy with only local numbing, you can usually eat normally. For sedation or anesthesia, follow the fasting instructions you are given.

The morning of

Medicines

Take your usual medicines unless told otherwise, except any blood thinner you were asked to pause.

Antibiotics

Some teams give one dose of antibiotic before the biopsy; many give none for this route.

Wear comfortable clothes

Bring loose underwear and pants. You may want a small pad in your underwear on the way home.

The procedure, step by step

Press play or pick a step. Each drawing shows what your surgeon is doing at that moment. Your team may do some steps differently.

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1. Getting into position

You lie on your back with your legs raised and resting in padded leg holders. The scrotum is gently lifted and taped out of the way, and the skin of the perineum is cleaned with antiseptic. If you are having sedation or general anesthesia, you will be asleep from here on.

More detail

Being in this position in front of a team can feel exposing. Staff keep you covered as much as possible and explain each step before they do it.

You lie on your back with your legs raised and resting in padded leg holders. The scrotum is gently lifted and taped out of the way, and the skin of the perineum is cleaned with antiseptic. If you are having sedation or general anesthesia, you will be asleep from here on.
More detail
Being in this position in front of a team can feel exposing. Staff keep you covered as much as possible and explain each step before they do it.
A lubricated ultrasound probe, about as wide as a thumb, is placed gently into the rectum. It makes live pictures of the prostate. You will feel pressure, like needing to have a bowel movement.
More detail
In a transperineal biopsy, the probe is used only for pictures. No needle passes through the rectal wall.
If you are awake, your urologist numbs the skin of the perineum with a small needle, which stings for a few seconds. Then, watching on ultrasound, more numbing medicine is placed deeper along the path to the prostate and around it. After a few minutes, most people feel pressure more than pain.
More detail
This is a perineal and periprostatic nerve block, usually with lidocaine. Even under general anesthesia, it is often given to reduce soreness afterward.
A needle guide is attached to the probe or placed against the skin. In a clinic, it is often a small device that lets every sample pass through one or two tiny skin openings on each side. In an operating room, a grid with rows of holes, like a small checkerboard, may be used to space samples evenly.
More detail
Office guides that use only a few skin punctures have made awake transperineal biopsy practical. Grid (template) biopsies can take many more samples and are sometimes used for repeat biopsies or detailed mapping.
Software lines up your MRI with the live ultrasound. The suspicious area from the MRI shows as a colored outline on the screen and moves as the probe moves. This lets your urologist aim at a spot that ultrasound alone often cannot see.
More detail
This is MRI-ultrasound fusion. Some urologists instead study the MRI closely and aim by eye, called cognitive fusion. A large trial named PRECISION found that MRI-targeted biopsy found more significant cancers and fewer harmless ones than random samples alone.
The biopsy needle is passed along the planned path into the target. When it fires, it makes a loud click and you may feel a quick, deep pinch. Usually 2 to 5 samples are taken from each target.
More detail
The spring-loaded needle has a notched inner part and an outer sleeve that snap forward in a fraction of a second, cutting a core about 1 to 2 centimeters long. Each core goes into its own labeled container so the lab can report exactly where any cancer was found.
Most teams also take about 10 to 12 samples spread across both sides of the prostate in a set pattern, which can find cancer the MRI missed. Then the probe is removed, firm pressure is held on the skin for a minute or two, and a small dressing goes on.
More detail
The exact pattern varies. Some men with a clearly abnormal MRI have targeted samples plus a few around the target, and some men with a normal MRI have only the systematic pattern. Your urologist chooses based on your MRI and history.

After the procedure

Right afterward

A short rest
You rest for 15 to 30 minutes, or longer after sedation, while the team makes sure you feel well.
Passing urine
Many teams ask you to pass urine before you leave. Some blood in it is normal.
Going home
Most people go home within an hour. If you had sedation, someone must drive you.
Pain
Most men need only acetaminophen (Tylenol). The perineum may feel bruised for a few days.

At home

Blood in the urine
Pink or light red urine is common for a few days and can come and go for up to 2 weeks. Drink extra fluids for the first day or two.
Blood in the semen
Semen may look red, rusty or brown for 4 to 6 weeks, sometimes longer. It is harmless to you and to a partner.
Soreness
A sore, bruised feeling where the needle went in is common. Sitting on a cushion and a cold pack wrapped in a cloth for 15 to 20 minutes at a time help.
The skin spots
Keep the dressing on for a day. You can shower the next day. The tiny needle marks heal within a few days.
Activity
Avoid heavy lifting, bicycle riding and hard exercise for about 2 to 3 days. Walking is fine.
Sex
You can resume sex when comfortable, usually after a few days. Expect blood in the semen.
Blood thinners
Restart any paused blood thinner as your team instructed, often within 1 to 2 days.
Work
Most people go back to work the next day, or the same day for desk work after local numbing alone.

Recovery timeline

Day 0
Biopsy day
The biopsy takes about 20 to 45 minutes. You go home the same day, a bit sore, with some blood in your urine.
Days 1 to 3
Settling down
Soreness eases. Urine gradually clears. Most people are back to normal routines.
Days 5 to 10
Results
The pathology report is usually ready. Your urologist goes over it with you, often at a clinic visit.
Week 2
Urine clear
Blood in the urine has usually stopped. Bruising has faded.
Weeks 4 to 6
Semen clears
Blood in the semen usually fades by now, though it can last longer.
After results
Next steps
Depending on the result, the plan may be repeat PSA tests, active surveillance, staging scans, or a talk about treatment options.

What it feels like

Most men dread the biopsy more than it deserves. The numbing stings, the clicks are startling, and the days after are a bit sore, but the hardest part for many is the wait for results.

Before the biopsy
Worry about pain, embarrassment about the position, and fear of what the results will show, often all at once.
What helpsAsk your urologist to walk you through the steps beforehand. Ask whether sedation is an option if you are very anxious. Bring someone with you.
The numbing
A sharp sting in the skin, then a deeper pressure or ache as medicine goes in around the prostate.
What helpsSlow breathing helps. Tell the team if you feel sharp pain later; more numbing can be given.
The clicks
Each sample comes with a loud snap and a quick pinch or deep thud. Many men flinch at the first one even when it does not hurt much.
What helpsAsk the team to count down before each one. Knowing roughly how many samples to expect makes it easier to get through.
Right after
Relief that it is over, a bruised feeling between the legs, and some blood in the first urine.
What helpsRest, drink water, and take acetaminophen if needed. A cushion makes sitting more comfortable.
The first ejaculation
Seeing red or brown semen can be alarming, even when you were told about it.
What helpsIt is expected and harmless, and it fades over weeks.
Waiting for results
The days of waiting can feel long. Many men replay every number and search online.
What helpsAsk when and how you will get results, and book the results visit before you leave. Bring someone to that visit to listen and take notes.

How well it works

The pathology report tells whether cancer is present and, if it is, how aggressive it looks and how much there is. Your urologist puts this together with your PSA and MRI to plan next steps.

Grade group (Gleason score)
Cancer is graded from grade group 1 (least aggressive, Gleason 6) to grade group 5 (most aggressive). Grade group 1 cancers usually do not need treatment and are often watched with active surveillance.
How much cancer
The report lists how many cores contain cancer and how much of each core is involved. More cancer, especially of higher grade, usually means treatment is advised.
Matching the MRI
Your urologist checks whether the targeted cores explain the MRI finding. If they do not, a repeat biopsy or closer follow-up may be advised.
Benign or uncertain findings
Many biopsies show no cancer, or show inflammation or unusual cells that are not cancer. Depending on your risk, the next step may be PSA checks, a repeat MRI, or sometimes another biopsy.

Risks

Every operation has risks. These are the ones people ask about most, with honest odds where good numbers exist. Your surgeon’s own results matter more than averages.

Common

Blood in the urineCommon

Common for a few days and usually mild.

Blood in the semenCommon

Common for 4 to 6 weeks or longer. Harmless.

Soreness and bruising

The perineum may be sore and bruised for a few days.

Less common

Trouble passing urineAbout 1 to 2 in 100

Swelling of the prostate can block urine for a short time, needing a catheter for a few days. It is more likely with a large prostate, existing urinary problems, or general anesthesia.

Fainting

Some people feel lightheaded or faint during or soon after the biopsy. Lying down for a few minutes helps.

Temporary erection changes

Some men notice weaker erections for a few weeks, often linked to soreness or worry. This usually passes.

Missing a cancer

A biopsy samples only part of the prostate and can miss a cancer. A rising PSA or a changing MRI may lead to a repeat biopsy.

Rare

Serious infectionWell under 1 in 100

Because the needle does not cross the rectum, serious infection is rare after a transperineal biopsy, but fever still needs urgent attention.

Heavy bleeding

Bleeding heavy enough to need a catheter, a hospital stay or a transfusion is rare.

Allergic reaction

A reaction to the numbing medicine, antiseptic or latex is rare.

Call your care team or go to the emergency room if

Fever of 101°F (38.3°C) or higher, or shaking chills.
You cannot pass urine, or only dribbles, with a full, painful lower belly.
Thick blood or clots in the urine, or bleeding that gets heavier instead of lighter.
Bleeding from the perineum that does not stop with 10 minutes of firm pressure.
Severe or worsening pain between the legs or in the lower belly.
Feeling faint, dizzy, or very unwell.

Questions to ask your surgeon

What did my MRI show, and how many targets will you sample?
Will you also take samples from the rest of the prostate?
Will I be awake with numbing, or asleep?
Do I need an antibiotic for this biopsy?
Should I stop any of my medicines or blood thinners?
How long will the blood in my urine and semen last?
When and how will I get my results?
What happens next if the biopsy shows cancer, and what if it does not?

Words you may hear

PSA: Prostate-specific antigen, a protein made by the prostate and measured with a blood test.
PI-RADS: A 1 to 5 score for how likely an area on prostate MRI is to be a significant cancer.
Perineum: The area of skin and muscle between the scrotum and the anus.
Transperineal: Going through the perineum, rather than through the rectum.
MRI-ultrasound fusion: Software that lays the MRI map over the live ultrasound picture so a needle can aim at an MRI target.
Core: A thin cylinder of tissue removed by the biopsy needle.
Targeted biopsy: Samples aimed at a specific suspicious area seen on MRI.
Systematic biopsy: Samples taken in a set pattern across the whole prostate.
Grade group: A 1 to 5 scale of how aggressive cancer cells look; 1 is the least aggressive.
Active surveillance: Watching a low-risk cancer closely with PSA tests, MRI and biopsies, and treating only if it changes.
Hematospermia: Blood in the semen.

Common questions

Does it hurt?

Most men feel a sting from the numbing, then pressure and a pinch with each sample. Under sedation or general anesthesia you feel nothing during the biopsy. Soreness afterward is usually mild.

Do I need antibiotics?

Often not. Because the needle does not cross the rectum, infections are rare, and many centers give no antibiotic or a single dose.

Why do I still need a probe in my rectum?

The prostate sits right in front of the rectum, so an ultrasound probe there gives the clearest live pictures to guide the needle. It is used only for imaging.

Can a biopsy spread the cancer?

There is no good evidence that a prostate biopsy spreads cancer in any way that matters for your health.

What if the biopsy is negative but my PSA stays high?

Your urologist may repeat the PSA, repeat the MRI, use another blood or urine test, or suggest another biopsy, depending on your risk.

Will this affect my erections?

A biopsy does not cause lasting erection problems for most men. Some notice a short-term change while sore.

Sources this page draws on

American Urological Association and Society of Urologic Oncology, Early Detection of Prostate Cancer: AUA/SUO Guideline (2023)
European Association of Urology, EAU-EANM-ESTRO-ESUR-ISUP-SIOG Guidelines on Prostate Cancer
New England Journal of Medicine, PRECISION trial: MRI-targeted or standard biopsy for prostate-cancer diagnosis (2018)
American Cancer Society, Tests to Diagnose and Stage Prostate Cancer

Written November 2026. This page explains what usually happens. It is not medical advice and does not replace a conversation with your own surgeon, whose plan for you comes first.