HIFU for prostate cancer: what it is and what the evidence says

What it is

HIFU (high-intensity focused ultrasound) is a treatment for localised prostate cancer, that is, cancer that has not spread outside the prostate. It focuses ultrasound on one point, like a magnifying glass focusing sunlight. That point heats up to more than 65 °C and the tissue is destroyed. There are no cuts: the energy comes from a probe placed in the rectum.

It can be done in two ways:

• Focal treatment. Only the area of the prostate where the tumour is located is treated, with a safety margin, and the rest is spared. The aim is to control the cancer with fewer effects on continence and erections.
• Whole-gland or extensive treatment. The whole prostate, or a large part of it, is treated when the tumour covers a wide area. Effects on continence and erections are more common than with focal treatment.

It has also been used when the cancer comes back in the prostate after radiotherapy (salvage treatment), in very carefully selected patients.

What studies show

In selected cases, recent studies show cancer control comparable to surgery in the medium term, with fewer effects on continence and erections:

• Compared with surgery. A French study in 46 hospitals, with more than 3,300 men with low- or intermediate-risk cancer, compared HIFU (of the whole prostate or a large part of it) with removal of the prostate. At two and a half years, the need for salvage treatment was no greater with HIFU. At one year, continence worsened in fewer men (29 in 100, compared with 44 in 100 after surgery) and erections were less affected.
• Focal treatment compared with surgery. A British study compared 246 men treated with focal therapy, most of them with HIFU, with another 246 men with similar characteristics who had surgery. At 8 years, the proportion of men who had not needed further treatment was similar: 83 in 100 with focal therapy and 79 in 100 with surgery.
• The largest focal HIFU registry. Among 1,379 men treated in 13 British hospitals, about 7 in 10 had not needed treatment of the whole prostate or other cancer treatments at 7 years.

It is also worth knowing their limits: in these studies patients were not randomly allocated to the treatments (in the French study, the men treated with HIFU were older), and follow-up does not yet reach 10 or 15 years. That is why careful selection of each case and follow-up matter so much.

Who may it be suitable for?

HIFU may be considered mainly in men with:

• Intermediate-risk cancer, confined to the prostate.
• A well-defined tumour area on the MRI, confirmed by a biopsy targeted at that area plus samples from the rest of the prostate. This reduces the risk of leaving another tumour untreated. I explain it on the prostate fusion biopsy page.
• The wish to preserve continence and erections, and willingness to have close follow-up.

It is not the treatment of choice when the prostate cancer is high risk, although it can be considered in selected cases. In low-risk cancer, active surveillance is usually recommended: treating it, with any technique, can be overtreatment.

It is not usually an option either if there are significant tumours in several areas of the prostate, if the cancer has spread outside the prostate or if problems in the rectum prevent the probe from being placed. In large prostates, tumours at the front are harder to reach.

What the treatment involves

This is what the treatment involves in my private practice, at UMI, where I perform it:

1. Planning. The MRI and the biopsy are used to know exactly where the tumour is and to plan the area to be treated.
2. Anaesthesia. It is done under general anaesthetic.
3. The treatment. The probe is placed in the rectum and the equipment applies ultrasound to the planned area, with imaging control throughout. There are no cuts or stitches.
4. Hospital stay. You spend one night in hospital.
5. Catheter. You go home with a urinary catheter, because the prostate swells after the treatment. The catheter stays in for a few days (usually between 2 and 5), depending on the size of the prostate, the area treated and any urinary symptoms you had beforehand.

I will explain at your appointment how many days you are likely to have the catheter.

Side effects and risks

With focal treatment, side effects are usually milder than with whole-prostate treatments:

• The first few weeks. Stinging, urgency and some blood in the urine or semen are common. There may be a urinary infection or difficulty passing urine when the catheter is removed.
• Continence. With focal treatment, most men remain continent.
• Erections and ejaculation. Erections may get worse, especially if the treated area is close to the nerves. The volume of semen usually decreases.
• Narrowing of the urethra. This is uncommon with focal treatment. If it happens, the stream becomes weak and another procedure may be needed.
• Fistula between the urethra and the rectum. This is rare but serious: an abnormal connection that usually needs surgery.

In the largest focal HIFU registry, serious complications occurred in fewer than 1 in 100 men.

With whole-gland treatment, side effects are more common. In the French study, in which the whole prostate or a large part of it was treated, about 10 in 100 men had urinary retention after HIFU; even so, continence and erections were less affected than after surgery.

Follow-up and the possibility of further treatment

After HIFU there is still healthy prostate tissue, so PSA does not fall to zero. That is why follow-up combines several checks: regular PSA tests, an MRI and, often, a biopsy of the treated area. There is no validated PSA value that on its own shows the treatment has worked.

It is wise to allow for the possibility of needing further treatment:

• In the largest focal HIFU registry, almost 1 in 5 men needed a second session of focal treatment.
• In the same registry, by 7 years about 3 in 10 men had needed treatment of the whole prostate or other cancer treatments.
• If needed, surgery or radiotherapy are still possible after HIFU.

Other options for localised prostate cancer

HIFU is not the only option. Depending on the risk of the tumour, your age, your health and your preferences, the following are also considered:

Active surveillance

Regular checks with PSA, MRI and biopsy, without treatment as long as the tumour does not change. This is what is recommended for low-risk cancer.

Surgery

Radical prostatectomy removes the prostate. It can be done with robotic surgery.

Radiotherapy

External beam or brachytherapy (radioactive sources inside the prostate), sometimes combined with hormone treatment.

The decision is shared, with clear information about what we know and what we do not yet know about each option.

Who performs it

Dr. Mario Domínguez Esteban is a urologist and Head of the Uro-Oncology Section at Marqués de Valdecilla University Hospital. In the private sector he performs it as part of his work at Urología Mínimamente Invasiva (UMI).

At Marqués de Valdecilla University Hospital we are taking part in a multicentre study on HIFU.

When to seek help

• Seek urgent medical attention if you cannot pass urine, if you have a fever or chills, if you pass clots in your urine, or if you notice gas or traces of faeces when passing urine, or urine coming from the back passage.
• Book a priority appointment with your doctor if, after a few weeks, the stinging, urgency or leakage does not improve, or if the stream becomes weak.

There is more detail in the warning signs.

Frequently asked questions