Radiation Therapy for Brain Metastases

Understanding external beam radiation therapy for brain metastases

• External beam radiation therapy may involve a series of outpatient treatments to accurately deliver radiation therapy to the whole brain.
• Sometimes the whole brain is given radiation, sometimes only a limited area. When the whole brain needs radiation treatments for brain metastases, treatments are usually given daily Monday through Friday for two to three weeks.
• In some cases, a single high dose radiation treatment called stereotactic radiosurgery can be used so treatment is completed in one day. With stereotactic radiosurgery doctors only target a small part of the brain. Sometimes combining both stereotactic radiosurgery with whole brain radiation therapy can be helpful.
• Before starting radiation, you will undergo a radiation “planning” session where the radiation treatment team creates a way to set your treatments up accurately on a day-to-day basis, generally with a custom fit mesh mask. However, sometimes other devices are used to help with accuracy of daily set up. You then undergo imaging in the treatment position, typically with a CT scan or fluoroscopy. The radiation oncologist then works with his or her treatment team to “prescribe” the radiation treatment.
• Tailoring each of the radiation beams allows doctors to target more of the cancer cells while sparing nearby organs, such as the eyes.