Gamma Knife radiosurgery is a type of radiation therapy used to treat tumors and other abnormalities in the brain.
In Gamma Knife radiosurgery, specialized equipment focuses close to 200 tiny beams of radiation on a tumor or other target. Although each beam has very little effect on the brain tissue it passes through, a strong dose of radiation is delivered to the site where all the beams meet.
The precision of Gamma Knife radiosurgery results in minimal damage to healthy tissues surrounding the target. In some cases, Gamma Knife radiosurgery may have a lower risk of side effects compared with other types of radiation therapy. Also, Gamma Knife radiosurgery is often a safer option than is traditional brain surgery.
Gamma Knife radiosurgery is usually a one-time therapy completed in a single day.
Gamma Knife radiosurgery is often an appropriate alternative to standard brain surgery (neurosurgery), which requires incisions in the skull, membranes surrounding the brain and brain tissue. This type of radiation treatment is usually performed when:
Gamma Knife radiosurgery is most commonly used to treat the following conditions:
Brain tumor. Radiosurgery is useful in the management of small noncancerous (benign) and cancerous (malignant) brain tumors.
Radiosurgery damages the genetic material (DNA) in the tumor's cells. The cells lose their ability to reproduce and may die, and the tumor may gradually shrink.
Arteriovenous malformation (AVM). AVMs are abnormal tangles of arteries and veins in your brain. In an AVM, blood flows from your arteries to veins, bypassing smaller blood vessels (capillaries). AVMs may disrupt the normal flow of blood and lead to bleeding.
Radiosurgery destroys the AVM and causes the blood vessels to close off over time.
Trigeminal neuralgia. Trigeminal neuralgia is a disorder of one or both of the trigeminal nerves, which relay sensory information between your brain and areas of your forehead, cheek and lower jaw. This nerve disorder causes disabling facial pain that feels like an electric shock.
After treatment, many people will experience pain relief within a few days to a few months.
Acoustic neuroma. An acoustic neuroma (vestibular schwannoma), is a noncancerous (benign) tumor that develops along the main balance and hearing nerve leading from your inner ear to your brain.
When the tumor puts pressure on the nerve, a person can experience hearing loss, dizziness, loss of balance and ringing in the ear (tinnitus). As the tumor grows, it can also put pressure on the nerves affecting sensations and muscle movement in the face.
Radiosurgery may stop the growth or minimize the size of an acoustic neuroma with little risk of permanent nerve damage.
Pituitary tumors. Tumors of the bean-sized gland at the base of the brain (pituitary gland), can cause a variety of problems. The pituitary gland controls hormones in your body that control various functions, such as your stress response, metabolism and sexual function.
Radiosurgery can be used to shrink the tumor and lessen the disruption of pituitary hormone regulation.
Gamma Knife radiosurgery doesn't involve surgical incisions, so it's generally less risky than traditional neurosurgery. In traditional neurosurgery, you may have risks of complications with anesthesia, bleeding and infection.
Early complications or side effects are usually temporary. They may include:
Don't eat or drink anything after midnight the night before the procedure.
Talk to your doctor about whether you can take your regular medications the night before or morning of the procedure.
Avoid wearing the following items during the procedure:
Tell your doctor if you:
Gamma Knife radiosurgery is usually an outpatient procedure, but the entire process will take most of a day. You may be advised to have a family member or friend who can be with you during the day and who can take you home. In some cases, an overnight stay in the hospital may be necessary.
You'll have an intravenous (IV) line, a tube that delivers fluids to your bloodstream to keep you hydrated during the day. A needle at the end of the IV is placed in a vein, most likely in your arm.
Before the procedure begins, you'll have a lightweight frame attached to your head with four pins. This frame will stabilize your head during the radiation treatment and serve as a point of reference for focusing the beams of radiation. During this process:
You'll receive numbing shots in the four places on your scalp where the pins will be inserted — two points on your forehead and two at the back of your head After the head frame is attached, you'll undergo imaging scans of your brain that show the location of the tumor or other abnormality in relation to the head frame. The type of scan used depends on the condition being treated:
The results of the brain scans are fed into a computerized planning system that enables the radiosurgery team to plan the appropriate areas to treat, dosages of radiation and how to focus the radiation beams to treat the areas. This planning process may take an hour or two. During that time, you can relax in another room, but the frame must remain attached to your head.
Children are often anesthetized for the imaging tests and during the radiosurgery. Adults are usually awake, but you may be given a mild sedative to help you relax.
You'll lie on a bed that slides into the Gamma Knife machine, and your head frame will be attached securely to a helmet inside the machine. The procedure may take less than an hour to about four hours, depending on the size and shape of the target. During the procedure:
After the procedure, you can expect the following:
The treatment effect of Gamma Knife radiosurgery occurs gradually, depending on the condition being treated:
The new TrueBeam™ System is an advanced radiotherapy technology for treating cancer.
Opening up treatment options for people with cancer, it targets tumors with accuracy measured in millimeters. With its power and flexibility, clinicians can develop treatments that are best suited for patients' individual circumstances.
The TrueBeam system brings leading edge cancer care to communities by positioning clinics at the forefront in the fight against cancer. Designed from the ground up to treat moving targets with advanced speed and accuracy, the TrueBeam platform is a fully-integrated system for image-guided radiotherapy and radiosurgery. TrueBeam treats cancer anywhere in the body where radiation treatment is indicated, including lung, breast, prostate and head and neck.
The number of physicians adopting advanced treatments like Stereotactic Body Radiation Therapy (SBRT) is rising. Technologies such as motion management, integrated imaging and high dose rates are some of the tools that are required for the delivery of advanced treatments like stereotactic body radiation therapy. TrueBeam channels innovative, intelligent, and intuitive thinking to provide technology built with the customer in mind. The system offers clinicians intelligent tools for a wide spectrum of advanced treatment options including SBRT. From fast imaging to accurate dose delivery, TrueBeam is designed to help clinicians navigate the complexities of cancer care with confidence.
The carefully guided, automated workflow on the TrueBeam system uses intuitive visual cues to enhance safety and reduce operation times so patient throughput can be optimized. Streamlined imaging and patient positioning tools enable more flexibility to treat clinical cases throughout the body. Having the power to not only treat quickly, but to deliver high, accurate dose rates are hallmarks of the TrueBeam system. Because TrueBeam is driven by reliability and has a clear technology roadmap, it is a secure long term investment for clinics as they continue to grow and evolve. With a track record of technology upgrades from Advanced IGRT, PerfectPitch, and Edge technology options, clinics worldwide have already adopted TrueBeam to help advance the way cancer is treated.
TrueBeam combines imaging, beam delivery and sophisticated motion management to accurately and precisely target tumors with speed.
Here are some quick facts:
TrueBeam rotates around the patient to deliver a prescribed radiation dose from nearly any angle.
An accessory called a multileaf collimator (or MLC) is what shapes the beam. It has 120 computer-controlled "leaves" or "fingers" that create apertures of different shapes and sizes. The leaves sculpt the beam to match the 3-D shape of the tumor. These can move and change during treatment to target the tumor and minimize dose to the surrounding healthy tissue.
TrueBeam's additional functionality provides for the acquisition of a cone-beam CT, a form of CT, using 25% less X-ray dose than compared with earlier Varian image-guided technologies. This means patients can be exposed to less X-rays/radiation.
Real-time imaging tools allow clinicians to "see" the tumor they are about to treat. This gives them confidence, and they can target tumors with accuracy measured in millimeters.
The system includes a new "gated" option for synchronizing beam delivery with respiration. This helps maintain accuracy as the system changes its targeting whenever tumor motion is an issue, for example during lung cancer treatments.
TrueBeam can be used for many forms of advanced treatment techniques including image-guided radiotherapy (IGRT), intensity-modulated radiotherapy (IMRT) and RapidArc ® radiotherapy technology. Because of this, patients can receive the treatment that is best suited for their specific clinical circumstances.