According to results recently presented at the annual meeting of the American Society of Therapeutic Radiology and Oncology (ASTRO), the addition of stereotactic radiation (gamma-knife surgery) to whole-brain radiation (WBRT) improves outcomes of patients with cancer spread (metastases) to the brain.
One common site for various types of cancer to spread is the brain. Historically, patients with brain metastasis were often treated with radiation to the entire head (WBRT). However, researchers have developed more precise delivery of radiation to the site(s) of cancer so that more radiation can be delivered to the cancer and healthy, surrounding tissue may be spared from the side effects of radiation. Stereotactic radiation (SRS) involves the precise three-dimensional delivery of radiation directly to the cancer.
Researchers from 34 medical institutions involved in the Radiation Therapy Oncology Group (RTOG) conducted a clinical trial to compare WBRT followed by SRS to WBRT alone in patients with brain metastases. The trial involved 333 patients with one to three sites of cancer in the brain and patients received either WBRT plus SRS or WBRT alone. One year following therapy, local control (control of brain metastases) was achieved in 82% of patients who received WBRT plus SRS, compared to 71% of patients who received WBRT alone. Patients with a solitary metastasis had an improvement in average survival from 4.9 months to 6.5 months and a survival benefit was achieved in patients who were under the age of 50 years with small cell lung cancer and any squamous cell cancer (including non-small cell lung cancer). In addition, SRS was associated with a significant improvement in a patient’s ability to perform daily functions. There was no increase in side effects in patients treated with SRS, compared to those treated with WBRT alone.
These researchers concluded that the addition of SRS to WBRT appears to improve control of brain metastases. Most patients treated with SRS died from cancer that had spread to places in the body other than the brain. Importantly, side effects were not increased with the addition of extra radiation. Patients with brain metastases may wish to speak with their physician about the risks and benefits of SRS or participating in a clinical trial evaluating other novel therapeutic approaches.
Reference: Sperduto P, Scott C, Andrews D. Stereotactic radiosurgery with whole brain radiation therapy improves survival in patients with brain metastases: report of radiation therapy oncology group phase III study 95-08.
International Journal of Radiation Oncology Biology Physics. 2002;54:3. Proceedings of the American Society of Therapeutic Radiation and Oncology (ASTRO 2002).