The Gamma Knife® and its associated computerized treatment planning software enable physicians to locate and irradiate relatively small targets in the head (mostly inside the brain) with extremely high precision. Intense doses of radiation can be given to the targeted area(s) while largely sparing the surrounding tissues. The Gamma Knife® can be used for a wide variety of problems as selected malignant tumors that arise in or spread to the brain (primary brain tumors or metastatic tumors), benign brain tumors (meningiomas, pituitary adenomas, acoustic neuromas), blood vessel defects (arteriovenous malformations) and functional problems (trigeminal neuralgia). The Gamma Knife® utilizes a technique called stereotactic radiosurgery, which uses multiple beams of radiation converging in three dimensions to focus precisely on tumor, permitting intense doses of radiation to be delivered to that volume safely. A multidisciplinary team approach provides patients with the greatest safety.
First of all, Leksell Gamma Knife® is not a knife at all. Your doctor makes no incisions in your head. Instead, Leksell Gamma Knife directs precisely focused beams of radiation at your brain tumor, lesion or other abnormality.
The Head Frame
One of the key components of Leksell Gamma Knife – the tool that allows your doctor to precisely pinpoint your tumor or problem – is the special stereotactic head frame.
This lightweight frame, which is attached to your head with four small screws, ensures that the radiation beams are precisely targeted. The frame also prevents your head from moving during the treatment procedure, which ensures that only the target area in your brain receives radiation.
After your head frame is in place, a number of advanced imaging tests – such as an MRI or CT scan – will be required to precisely locate the size, shape and location of your tumor, lesion or abnormality.
If your physician is treating a blood vessel abnormality, an angiogram may also be required. As you may already know, an angiogram involves the injection of a dye into your bloodstream so that the imaging procedure clearly shows the blood vessels and arteries in the brain.
The coordinate markers on your head frame, which are part of the images taken, will help your physician develop an exact plan for your procedure.
Once your images have been taken, you can sleep, rest or relax while your physician develops your specialized treatment plan. First, your brain images are computerized. Then, using Leksell Gamma Knife 3-D planning software, a treatment protocol is planned.
No two treatment plans are alike; every patient’s plan is specifically designed to address his or her specific medical condition.
Because Leksell Gamma Knife includes a set of unique helmets that have 201 holes for the precise delivery of radiation to your brain, your plan will consist of one or more treatments using these helmets.
Once your treatment plan is complete, you’ll lay down on the treatment table and your head frame will be attached to the helmet for your first treatment. You’ll be awake during the procedure and able to communicate with your Leksell Gamma Knife team through a video and audio connection.
When Gamma Knife® Surgery begins, the treatment table, w
hich is much like the one you were on for your MRI or CT scan, will move into the dome section of the unit.
The team will be monitoring your procedure at all times. There may be several treatments lasting anywhere from two to forty-five minutes during your Leksell Gamma Knife session.
Back to your normal routine
Once your treatment is complete, the head frame will be removed. If you had an angiogram, you might have to lie quietly for several more hours. Some patients experience a mild headache or minor swelling where the head frame was attached, but most report no problems. Your doctor will tell you whether or not he wants you to stay overnight for observation or if you can go home immediately. Either way, you should be able to return to work or your normal routine in another day or so.
The effects of your Leksell Gamma Knife treatment will occur over time. Radiation treatments are designed to stop the growth of tumors or lesions, which means they won’t disappear immediately but over a period of weeks or months. Your physician and Leksell Gamma Knife® team will stay in contact with you to assess your progress, which will include follow-up MRI or CT images in the near future and periodic check-ups.
Leksell Gamma Knife® Perfexion™ – stereotactic radiosurgery system
Perfexion dramatically streamlines workflow and expands the treatable volume through an automated, multi-source collimator.
System benefits include faster set-up and treatment delivery to one or more tumors in a single session.
Perfexion allows treatment of a wider range of targets faster and more efficiently than ever before.
The radiosurgery system’s unique collimator is a permanent device divided into moveable sectors, ensuring superior conformity, accuracy and dosimetry while reducing residual dose to unintended areas. Integrated and intuitive treatment planning software facilitates creation of even the most complex plans (e.g., a donut-shaped dose distribution) by configuring composite shots that avoid overexposure to critical structures. Perfexion is fine-tuned to the task, resulting in fast, efficient treatments.