High-intensity focused ultrasound (HIFU)

High-intensity focused ultrasound (HIFU) uses focused sound waves to heat and destroy a targeted area of tissue while leaving nearby areas unharmed. It's generally done under the guidance of MRI or ultrasound imaging. HIFU involves no incisions, lasers or radiation.

HIFU treats prostate cancer, uterine fibroids, essential tremor, Parkinson's disease and cancer-related bone pain.

Healthcare professionals also perform cosmetic procedures with HIFU. It may be used in care involving the face and eyes, jawline and neck, stomach, vagina, brain, and skin.

High-intensity focused ultrasound also may be used to deliver chemotherapy medicines for some cancers.

HIFU is given in an outpatient setting. Because HIFU is minimally invasive, you may recover more quickly or with less pain than with surgery.

Types

There are several types of high-intensity focused ultrasound. Each is based on where it is used in the body and what imaging is used to guide it.

• Magnetic resonance-guided focused ultrasound (MRgFUS) uses an MRI scanner for detailed images and real-time temperature monitoring. Because of its high accuracy, it's particularly useful when the targeted area is deep below the skin or close to important tissues in the body. It's commonly used to treat uterine fibroids and bone pain from cancer, as well during certain brain procedures.
• Ultrasound-guided HIFU uses standard ultrasound imaging. It doesn't require an MRI machine, so it may be more widely available. Ultrasound-guided HIFU may be recommended for fibroids, adenomyosis and some soft tissue tumors.
• Prostate HIFU uses a probe placed inside the rectum area to deliver treatment directly to the prostate. It targets small, well-defined areas and is used for prostate cancer that hasn't spread. In some cases, it may be used for benign prostatic hyperplasia (BPH).
• Brain HIFU, also called MR-guided thalamotomy, is a specialized form of MR-guided HIFU. It treats essential tremor by targeting a tiny area in the thalamus deep in the brain that causes tremors. A head frame focuses hundreds of ultrasound beams through the skull.
• Cosmetic HIFU uses ultrasound energy to tighten skin sagging or loose skin.

All types of HIFU work the same way, using focused sound waves to heat and destroy a small area of tissue. But the equipment, treatment position and degree of precision differ depending on the type.

High-intensity focused ultrasound is used for many conditions, including:

• Prostate cancer. HIFU is typically recommended for people with prostate cancer tumors that have not spread, affect only one part of the prostate and are slow growing. It may be given to people whose prostate cancer comes back after radiation.

  Focal HIFU destroys prostate cancer tissue that's in part of the prostate. Whole-gland HIFU destroys cancer tissue in all of the prostate. Focal or whole-gland HIFU may be an alternative to surgery or radiation for some people. Because HIFU is a focused treatment, it can lessen the risk of side effects of prostate treatment, including urine leakage and erectile dysfunction.

• Uterine fibroids. HIFU may be used to shrink uterine fibroids that cause pelvic pressure or heavy menstrual bleeding without removing the uterus. In rare cases, it may be used to treat adenomyosis.
• Essential tremor. When medicine no longer manages essential tremor, HIFU may be used to target a small region deep in the brain that controls movement, called the thalamus. This treatment can reduce shaking in the head and hands.
• Metastatic bone pain. When cancer spreads to the bone, HIFU can target painful areas to reduce discomfort. Cancers that are likely to spread to the bones include breast cancer, kidney cancer, lung cancer, thyroid cancer and prostate cancer. Lymphoma and multiple myeloma are blood cancers that may spread to the bones.
• Cosmetic skin tightening. When used to improve appearance, the sound waves tighten and lift skin by stimulating collagen growth in the face, neck and other parts of the body. Collagen is a protein in skin and other tissues that gives the body shape and strength. To reduce the risk of skin damage, HIFU used for cosmetic procedures involves lower energy than HIFU used for medical treatment.

Researchers are looking at HIFU as a treatment for liver cancer, pancreatic cancer and soft tissue tumors. HIFU also is being studied for health conditions such as endometriosis, ectopic pregnancy and placenta accreta.

High-intensity focused ultrasound has a low to moderate risk in most uses. Risks vary depending on the area treated, your overall health and other factors. Most side effects are mild and temporary.

Possible side effects from prostate cancer treatment include:

• Urinary urgency, leakage or incontinence, frequency, or mild burning.
• Short-term fatigue or pelvic discomfort.
• Blood in urine for a few days.
• Temporary urinary retention.
• Infection or inflammation.
• Erectile dysfunction.
• Ejaculatory dysfunction, also called dry orgasm.
• Rectal injury or fistula, which is rare.

Possible side effects from uterine fibroids treatment include:

• Mild abdominal pain or cramping.
• Temporary vaginal discharge.
• Low-grade fever or a change in skin color over the treated area, most often a shade of red, brown or purple.
• Pain.
• Minor skin burns.
• Bleeding.
• Bruising.
• Bowel or bladder injury, which is rare.

Possible side effects from essential tremor treatment include:

• Headache or nausea.
• Trouble swallowing.
• Slurred speech or trouble speaking.
• Tingling or numbness in the face or fingers.
• Mild balance problems or unsteady walking.

Occasionally, some side effects may linger more than a few weeks. Healthcare professionals don't always know who may be affected. Your care team can talk with you about your overall health and your risk of side effects.

Possible side effects from treatment of cancer-related bone pain include:

• Pain during or after treatment.
• Skin irritation.
• Nerve irritation.
• Minor burns after treatment.

Possible side effects from cosmetic care or skin tightening include:

• A change in skin color, mild swelling or tingling of skin.
• Minor bruising or tenderness.
• Skin irritation or burn.
• Nerve irritation.

Your care team determines whether HIFU is safe and appropriate for you. To do this, the team considers your other health conditions, pregnancy status and any other concerns.

Preparation for HIFU varies depending on the reason for treatment and the area of the body being treated. Your healthcare team gives you specific instructions to follow before the procedure.

Wear loose clothing to your HIFU appointment. It's a good idea to leave valuables at home.

Before the procedure

In most cases, you undergo imaging such as MRI before HIFU treatment to locate the target area and plan treatment. If you are receiving HIFU for a tremor, you may be asked to perform tests of your coordination before treatment.

For some HIFU procedures, your care team may ask you to stop taking certain medicines, such as blood thinners or supplements. You also may be asked to fast, perform a bowel prep, or avoid using lotions or creams on your skin.

Before your HIFU begins, you may be asked to remove any jewelry or hair accessories from the area being examined. You may need to remove or reposition clothing or change into a gown. You may be asked to lie on an exam table.

During the procedure

You are placed in a specific position on a table or chair for optimal treatment. For example:

• For prostate treatment, you are on your side or back.
• For fibroid treatment, you are face down.
• For essential tremor treatment, you wear a special head frame during treatment. The frame is removed after your treatment.

You may be fully conscious, lightly sedated or fully asleep, depending on your reason for treatment. For instance, for prostate treatment you'll receive general anesthesia, which puts you to sleep. If you're undergoing treatment for essential tremor, you'll be fully awake so your care team can monitor your speech and thinking.

During cosmetic procedures, you may feel warmth or tingling on the skin. Fibroid treatment may result in slight discomfort such as mild cramping.

The length of the procedure varies by the part of the body being treated. HIFU treatment can last anywhere from one hour to a few hours.

After the procedure

Following HIFU treatment, you are monitored to make sure you don't have any reactions or complications. Most people can go home the same day. Depending on the procedure and type of anesthesia given, you may need someone to drive you home afterward.

Some treatments require a catheter to be in place for several days after HIFU. The catheter typically remains in place for 5 to 7 days after HIFU for prostate cancer. People who've had treatment for prostate cancer may have urinary symptoms, such as a weak stream or burning during urination. Your care team teaches you how to manage a catheter if you receive one.

Your care team may give you instructions about when to wash your face, bathe and perform other self-care routines.

Some people can do light activity within a day or two of treatment and can resume their regular activities soon after that. But others may need more time to heal. Talk with your healthcare team about any restrictions related to your treatment.

For cosmetic procedures, regular activities can resume immediately. There may be a mild change in skin color or swelling of the skin for a few hours.

Results of HIFU treatment vary depending on the reason for treatment, the seriousness of the condition, your overall health and other factors. Your healthcare team can tell you what outcomes are possible for your situation.

For some conditions, such as prostate cancer and fibroids, you may need more than one treatment. Ask your care team what to expect.