Focal therapy with HIFU (high-intensity focused ultrasound) - information & specialists

What is high-intensity focused ultrasound (HIFU)?

High-intensity focused ultrasound (HIFU) works with bundled ultrasound waves. These waves meet at one or more points where they generate a temperature of around 90 °C. The treated tissue becomes hot and the tumor cells die. The body then breaks them down.

Ultrasound devices contain a probe that emits the energy and a type of camera. This measures the affected area of the body and displays it as an image. This allows the doctor to direct the ultrasound precisely at the diseased area of the body. Nearby areas (such as the rectum) are spared. Vascular-nerve bundles, which are necessary for an erection, remain intact.

Reasons for treatment: For which diseases is HIFU used?

High-intensity focused ultrasound is mainly used in the treatment of prostate cancer. The advantage of HIFU treatment is that no incisions, implants or radiation are required. If the cancer recurs, further HIFU treatment is possible.

Focal therapy is suitable in connection with prostate cancer:

• For the treatment of localized prostate cancer (type 1/type 2)
• For the treatment of recurrences (new diseases)
• For treatment after brachytherapy or radiotherapy
• If surgery is not desired or not possible

Today, doctors also use HIFU for breast cancer and benign tumors in the uterus(uterine fibroids). HIFU can also be used to treat thyroid nodules. However, the HIFU procedure is not suitable for all types of thyroid tumors, but only for benign nodules.

With HIFU treatment , cancer cells in the prostate can be gently destroyed without affecting the surrounding tissue. @ wangmando / AdobeStock

How does HIFU treatment work?

During treatment, the patient lies on a treatment table for around 1.5 to 2.5 hours. The treatment is usually carried out under partial anesthesia. If the patient so wishes, general anesthesia is also possible.

The doctor plans and controls the treatment procedure using a control panel. Computer control enables precise guidance of the ultrasound probe. This minimizes the risk of side effects and complications. The doctor inserts the probe into the rectum and places it directly next to the prostate. It then generates the high-intensity focused ultrasound. If necessary, hundreds of ultrasound scans can be started. The doctor carries out the treatment until sufficient tumor tissue has been burned away.

The computer enables a three-dimensional representation of the prostate on the screen. This allows the doctor to precisely define the tissue to be treated and to apply ultrasound with millimeter precision. The ultrasound device has safety features that interrupt the treatment immediately if the patient moves.

Types of HIFU treatment

There are several basic treatment strategies for HIFU therapy.

• Full treatment (with or without nerve preservation):

If prostate cancer is detected on both sides, the doctor treats the entire gland. To do this, the doctor must remove prostate tissue with an electric snare via the urethra. Depending on the location and aggressiveness of the tumor, nerve preservation is possible.

• Hemiablation:

If the tumor is on one side, the prostate is treated on one side. In this case, it is not necessary to ablate the prostate.

• Zonal treatment:

The treatment area includes the cancerous focus and the directly adjacent tissue.

• Focal therapy:

If there is a single demarcated tumor, the doctor can sonicate it with a safety margin.

The higher the PSA value, the greater the probability that prostate cancer is present @ angellodeco / AdobeStock

Patient behavior after treatment: aftercare

Patients can usually walk again around five hours after the treatment. Hospitalization after HIFU therapy usually lasts three to seven days.

Follow-up care after HIFU therapy takes place every three months. The PSA value is used as a guide for the success of the treatment. This indicates how much prostate-specific antigen the prostate gland produces. If the cancer has been destroyed, this value drops significantly. If the PSA value rises again, this is referred to as a relapse.

If the situation appears stable, the follow-up intervals are initially extended to six and later to twelve months.

Side effects and risks of HIFU therapy

The following side effects may occur immediately after HIFU treatment:

• Pain and slight burning
• Swelling: The surrounding tissue swells, so a bladder catheter may be necessary in the first few days.
• Blood in the urine: In the first few weeks , the first drops of urine are often bloody. Sometimes the urine contains pieces of tissue. This is normal as the dead tissue is shed in this way.
• Blocked urethra: This happens when too much tissue is shed at the same time. As a result, the initially good urine flow deteriorates again. In this case, it is necessary to aspirate the tissue through the urethra in a second inpatient procedure. Prostate resection prior to HIFU treatment reduces the risk of this complication.
• Inflammation of the urethra, prostate, bladder, testicles and epididymis: Although this occurs only rarely, it is possible, and a prophylactic antibiotic prevents infection symptoms such as frequent urge and burning urination. This is not always successful.
• Dribbling urine when coughing, straining or heavy lifting: because the external sphincter muscle of the bladder is weakened. This occurs in around five percent of patients. This problem can usually be remedied with pelvic floor exercises.
• Impotence: With a complete HIFU treatment (up to the prostate capsule), there is a certain risk of damaging the neurovascular bundle. The result is impotence. In almost 50 % of patients, however, erectile function is completely preserved.
• Fistula formation: In less than one percent of all patients, there is a faulty connection between the bowel and prostate.

Conclusion: good prognosis, no long-term data

Focal HIFU therapy is a minimally invasive treatment method for prostate cancer. It is particularly suitable for patients for whom surgery or radiotherapy is not an option. The procedure offers good chances of cure and improvement. However, no long-term data is available to date.