Dr. Terence Roberts is a radiation oncologist at Banner MD Anderson Cancer Center.
Question: I have heard stereotactic radiosurgery can reduce radiation exposure to the brain. Can you please explain this?
Answer: Stereotactic radiosurgery (SRS) involves a single, precisely directed, high-dose treatment of radiation that tightly conforms to the targeted tumor in the brain. Because a high dose of radiation is used, it is very important that the patient does not move during treatment. The patient’s head is carefully immobilized during the treatment planning process, and a CT scan and MRI are taken in the treatment position.
The CT and MRI images are then transferred to a treatment planning system. This system generates a plan that greatly reduces radiation exposure to the normal brain in comparison to conventional radiation. During treatment, precise imaging is critical to make sure the position of the targeted tumor is the same as during the treatment planning process. Imaging is also performed during treatment to confirm that the patient does not move.
Not all patients are candidates for SRS. The best candidates for SRS are those patients who have benign brain tumors, a few metastatic lesions in the brain, or primary brain tumors that have not responded to initial therapy. Large tumors or tumors associated with a large amount of swelling are better treated with surgery or conventional radiation.