Radiation is often an important treatment option for brain metastases. However, there are no uniform guidelines for the best time. A study at the USZ now aims to clarify when the effect is greatest, the risks are low and the treatment has the least impact on patients' quality of life.
Thanks to medical advances and improved therapies, many cancer patients today have a significantly longer life expectancy than just a few years ago. However, the longer the survival time, the greater the likelihood that metastases, offshoots of the original cancer, will develop in other organs or regions of the body. In patients with melanoma(skin cancer), lung cancer, breast cancer and kidney cancer, metastases often form in the brain; around 30 percent of all patients whose cancer leads to metastases are affected by brain metastases. Brain metastases can lead to a wide range of symptoms and severe discomfort and impairment, from headaches and paralysis to personality changes and epileptic seizures. Without treatment, patients have a poor prognosis: their average survival time is only a few weeks.
Radiation is often the only important therapy
The treatment of brain metastases is difficult because the usual therapies are only effective to a limited extent. Surgical removal of brain metastases is only possible in a small number of patients. Traditional chemotherapies are often not very effective, partly because many of the active substances do not penetrate the blood-brain barrier and do not reach the brain. The new immunotherapies often produce good initial results, but the tumor cells can become insensitive after a short time. In many cases, therefore, the only remaining therapy is radiation. High doses of radiation can be applied locally in just a few sessions. Unlike the whole-brain irradiation used in the past, this high-precision irradiation causes significantly less long-term damage.
The best time is not known
If radiation is administered immediately after diagnosis, this increases the long-term risk of side effects in the brain, such as loss of cognitive abilities or neurological deficits, which have a negative impact on quality of life. For this reason, radiotherapy is often only started when other treatment options are not available. However, early radiotherapy could perhaps also bring the brain metastases under better control. This makes it all the more important to use the therapy precisely when the treatment is most effective for the patient and the risk of impairment is lowest. However, the best time for irradiation is not clear even among experts; there is a lack of meaningful data and no standardized guidelines for high-precision irradiation.
“STRIKE” study aims to improve treatment
The STRIKE clinical trial of the Comprehensive Cancer Center Zurich (CCCZ) at the USZ, which is due to start soon, is now investigating various questions relating to the radiotherapy of brain metastases and aims to obtain the missing data and information on the best time to start radiotherapy. Specialists from neurology, neurosurgery, radio-oncology, medical oncology and hematology and the dermatology clinic work together on this research. It is planned that other university hospitals in Switzerland and abroad will also be involved in the study.
One main study and several integrated accompanying studies are investigating whether early radiotherapy together with medication leads to better control of brain metastases. The study should also provide insights into whether brain-damaging side effects depend on the time of irradiation and whether the type of tumor must also be taken into account for the treatment to be most effective. Last but not least, the results can help to establish standardized guidelines for high-precision irradiation.
Accompanying study on quality of life
One of the accompanying studies is also dedicated to the patients’ quality of life. Studies and surveys are intended to provide information on the extent to which cognitive impairment actually occurs as a result of early radiotherapy and how this risk relates to the possible control of metastases and the preservation of cognitive abilities and affects patients’ quality of life.
“Reliable findings on these questions would be a great help for the doctors treating patients,” says Michael Weller, Director of the Department of Neurology and head of the study, summarizing the aim of STRIKE. “Because this enables us to offer our patients the best treatment for them based on the latest research. And the best treatment means the most effective therapy with the best possible quality of life, individually for each patient.”
The study is financed by various benefactors via the USZ Foundation.
