Gamma knife: Radiosurgery Gamma Knife for Arteriovenous Malformation (AVM)
Radiosurgery with Gamma Knife is the most advanced way to treat arteriovenous malformations (AVM). The method implies irradiation of lesions with high doses of radiation from a variety of angles. After the procedure, the abnormal shunts are occluded gradually, resulting in restoration of the normal blood flow in the brain.
As the main method of therapy, Gamma Knife is indicated for AVM less than 3 cm. The treatment effectiveness in such cases is 95%. Complete occlusion of defective blood vessels is developed within 1 to 3 years after the intervention.
For large formations, the Gamma Knife is used in combination with surgery or as the sole method of therapy, if AVMs are located in awkward surgical areas. In the latter case, the vascular tangle is irradiated in parts for several years.
Radiosurgery is performed in a single day. Under local anesthesia, a special frame with a three-dimensional coordinate system is installed on the patient's head. Next, CT and/or MRI are conducted to determine the precise location of malformations. The resulting data are entered into Gamma Knife software, which develops an individual treatment plan.
The patient is placed on the table, and his head is fixed so that the radiation affected the pathological focus precisely. After switching on of the installation, the selected area is exposed to 200 thin beams of gamma rays from different sides. Each beam is harmless to healthy tissue, however, converging in the area of malformation, they create a dose of radiation highly damaging to cell.
Treatment duration ranges from 20 to 60 minutes, depending on the formation size. All this time, the radiation oncologist monitors the patient’s condition continuously. The bilateral audio communication is maintained.
Exposure to the Gamma Knife is painless, so it does not require anesthesia. After treatment completion, the frame is removed from the patient's head, and the dressing is applied. The patient can go home the same day or the next day.
In the future, the intervention effectiveness is monitored by regular examinations using CT or MRI. In the event of insufficient expression of the outcome, the procedure can be repeated.Hide