MR-HIFU therapy of desmoid tumors

Desmoid tumors are tumors that form on the sheaths of muscles. Due to the fact that they tend to infiltrate and grow into the surrounding tissue, these generally benign tumors cause severe pain and movement restrictions and often cannot be completely removed surgically or tend to grow back. In addition to surgical removal, HIFU therapy is therefore available at the University Hospital of Cologne as a non-invasive treatment method.

If you are interested in undergoing MR-HIFU therapy to treat your desmoid tumor or have been referred to us by your treating physician, you can find out more about this treatment method below.

If you would like more information or have a specific treatment request, please contact us at mr-hifu.therapie@uk-koeln.de.

Why is MR-HIFU therapy suitable for desmoid tumors?

HIFU (high-intensity focused ultrasound) is a non-invasive treatment method and offers an effective alternative to surgery and/or drug therapy. Similar to focusing the sun's rays on a spot with a magnifying glass, the HIFU procedure focuses a large number of ultrasound waves non-invasively through the skin and the underlying tissue onto the desmoid tumor. This heats the tissue to temperatures above 60 ˚C and burns the cells of the desmoid tumor. The surrounding tissue and skin are spared, as the heat only develops in the focal point. HIFU treatment is performed in a magnetic resonance imaging (MRI) scanner, which allows the doctor to obtain MRI images of the desmoid tumor and surrounding tissue to guide and monitor the therapy.

What are the benefits of MR-HIFU therapy?

One of the biggest advantages of MR-HIFU treatment is that the procedure is completely non-invasive, i.e. it does not require any (surgical) intervention and has few side effects. There is no surgery, so some patients prefer HIFU therapy to surgery for cosmetic reasons. In addition, desmoid tumors tend to grow again in the area of an operation. In a large number of cases, a complete regression of the desmoid tumor or an interruption of growth has been observed.

Who is eligible for MR-HIFU therapy of desmoid tumors?

In principle, MR-HIFU therapy is suitable for patients who decide against surgery for symptomatic or progressive tumors or for whom surgery is not possible or has produced only inadequate results. In order to determine whether a patient is eligible for MR-HIFU therapy, it is essential to perform a CT or MRI scan in advance to examine the exact location of the desmoid tumor and thus the accessibility for MR-HIFU.

For whom is MR-HIFU treatment of desmoid tumors not suitable?

Patients should always discuss the extent to which MR-HIFU treatment is possible and appropriate with the responsible radiologist in advance, especially if they have metal parts in their body (surgical staples or screws, pacemakers, dentures, etc.), extreme claustrophobia, pregnancy or allergies to contrast agents. In general, CT or MRI imaging is performed in advance to ensure that MR-HIFU treatment is possible. MRI imaging may also be requested as a follow-up.

How can I prepare for the treatment?

Patients can take a shower the evening before and should shave the area of the body to be treated. It is important not to apply cream or oil to this area of the body afterwards. On the day of treatment, patients should arrive sober. The last meal should be eaten at least 12 hours before the treatment. A small glass of water can be drunk on the morning of the treatment day. Any medication currently being taken should be mentioned during the consultation and the doctor should be consulted.

What exactly happens during the treatment?

As the treatment itself can be painful, it is carried out under anesthesia. The patient is monitored by the radiologists and anesthetists throughout the therapy. MR-HIFU therapy allows the treatment of various localizations of the body such as extremities and pelvis. The HIFU ultrasound transducer is built into the patient table of an MRI scanner. For treatment, the patient is positioned under anesthesia with the area to be treated over the ultrasound transducer. The first step is to obtain images of the desmoid tumor and the surrounding tissue in order to plan the treatment. Using these images, the radiologist can then direct focused ultrasound waves at the desmoid tumor and heat the tissue in a targeted manner, whereby the tissue temperature achieved, including that of the adjacent tissue, is continuously measured and monitored with the aid of the magnetic resonance tomograph (real-time image control). Depending on the location of the tumor, the therapy usually takes between 3 and 5 hours. At the end of the treatment, an MR contrast agent is injected to evaluate the treatment.

What happens after the treatment?

As with the treatment of osteoid osteomas, patients remain in the University Hospital for one night for observation. Just a few days after the treatment, most patients experience pain relief, which leads to an improvement in their quality of life.

• Read more about our equipment here
• Interventional radiology and MR-HIFU as a focus at the institute
• Research in experimental imaging and interventional radiology