Bone metastases: precision rays thanks to stereotaxy

“Radiotherapy by stereotaxy may restrict bone metastases for good in some patients!”: Philip Poortmans, Head of the Oncology/Radiotherapy Department at Institut Curie, will be exploring the latest indications and strategies on 22 October at the European Society for Medical Oncology‘s annual congress in Munich.

Metastases are secondary tumors that develop away from the primary site, and are difficult to treat. When they develop in bones, they cause pain, muscle weakness, sometimes paresthesia (feelings of numbness, tingling, pins and needles) and fractures. If they occur in the vertebrae, these fractures can cause spinal cord compression and paralysis in the lower body.

Yet several techniques can be used against metastases, in addition to direct anti-tumor approaches such as hormone therapy, chemotherapy and other types of systemic treatment: painkillers and anti-inflammatory medication as well as different types of radiotherapy chosen based on the number and location of the metastases, symptoms caused and the type of primary cancer. A little over a decade ago, stereotactic radiotherapy was added to the list. This treatment involves high-precision action on metastases via precision imaging followed by 3D contouring. Because these techniques ensure experts are able to accurately target the metastasis and at the very most any healthy tissue surrounding it, they are able to use extremely high-dose rays in just a few sessions - sometimes even in a single session. This is called hypofractionated stereotactic radiotherapy. This approach relieves pain and compression and can even “block metastasis progression in localized areas in 85% to 90% of cases when the stereotactic radiotherapy is used correctly, meaning on patients with a small number of (oligometastatic) metastases that can all be treated, and who are not suffering from aggressive forms of cancer that might trigger metastases elsewhere,” according to Prof. Poortmans, who will be explaining this to medical oncologists in Munich.

Fortunately, he adds, “metastases are increasingly being prevented thanks to early cancer diagnoses and effective forms of treatment: surgery and/or radiotherapy on the original tumor and systemic treatment (chemotherapy, hormone therapy and others) to kill off any potentially tumorous cells in the body that may develop into metastases. Just 5% of breast cancer patients in western countries have metastases at the time they are diagnosed. But 25% of them may go on to develop them at a later stage, sometimes many years later...”.