MR-HIFU therapy of bone tumors and bone metastases

Bone metastases form from cancer cells that spread from the original tumor (e.g. lung, prostate or breast cancer) and lead to metastases in the bone. The growth of these bone tumors leads to pressure on the surrounding periosteum, which causes severe pain and severely impairs the patient's quality of life. In addition to radiotherapy and drug treatment, HIFU therapy is 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 bone tumor or bone metastasis 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 bone tumors and metastases?

MR-HIFU (magnetic resonance-guided high-intensity focused ultrasound) therapy has been used at the University Hospital for several years for various diseases such as prostate cancer, benign uterine tumors and bone tumors. Similar to focusing sunlight on a point with a magnifying glass, the HIFU procedure focuses a large number of ultrasound waves non-invasively through the skin and through the underlying tissue onto the bone. This heats the bone surface and periosteum to temperatures above 60 ˚C, which burns the nerves in the tumor and periosteum and thus interrupts the transmission of pain. 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 bone 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. there is no (surgical) intervention, and has few side effects with usually rapid pain relief. Several studies have shown that MR-HIFU therapy effectively relieves pain and improves quality of life. After HIFU therapy, drug-based pain therapy can often be reduced or is no longer necessary.

Who is eligible for MR-HIFU therapy for bone tumors and metastases?

In principle, MR-HIFU treatment is suitable for patients with painful bone metastases. MR-HIFU therapy is therefore also an alternative to radiotherapy and is also possible if radiotherapy of the metastasis is not (or no longer) an option. In order to determine whether a patient is suitable for MR-HIFU therapy, it is essential to perform a CT or MRI scan in advance to examine the exact location of the bone metastasis and thus the accessibility for MR-HIFU.

For whom is MR-HIFU treatment of bone tumors and metastases not suitable?

Patients should always discuss with the responsible radiologist in advance to what extent MR-HIFU treatment is possible and appropriate, especially if they have metal parts in their body (surgical staples or screws, pacemakers, dentures, etc.), are extremely claustrophobic, are pregnant or are allergic to contrast agents. In general, CT/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?

The evening before, patients can take a shower and should shave the area of the body to be treated. Afterwards, it is important not to apply cream or oil to this area of the body. Patients should have an empty stomach on the day of treatment. 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. If the patient is currently taking medication, this should be mentioned during the consultation and the doctor should be consulted.

What exactly happens during the treatment?

As the treatment can be painful due to the sclerotherapy of the nerves, it is carried out under anesthesia. The patient is monitored by radiologists and anesthetists throughout the treatment. MR-HIFU therapy allows the treatment of a wide variety of bones, such as extremities or pelvic bones. The HIFU ultrasound transducer is built into the patient table of a magnetic resonance tomograph. For treatment, patients are put under anesthesia and positioned with the area to be treated above the ultrasound transducer. The first step is to obtain images of the bone metastasis and the surrounding tissue in order to plan the treatment. Using these images, the radiologist can then direct focused ultrasound waves at the bone metastasis and heat the bone surface in a targeted manner, whereby the tissue temperature achieved in the adjacent tissue is continuously measured and monitored using the magnetic resonance tomograph (real-time image control). Depending on the location of the metastasis, 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