Frequently Asked Questions
The Gamma Knife Perfexion is not actually a knife at all. It is a stereotactic radiosurgery device or cyberknife that uses up to 192 beams of cobalt-60 radiation to treat a variety of brain diseases and abnormalities in a single (one day) patient visit. Gamma Knife radiosurgery treatment provides non-invasive, extremely precise “surgical or knife-like” treatment with no incisions or general anesthesia.
Utilizing advanced diagnostic imaging and three-dimensional treatment planning software, Gamma Knife delivers up to 192 precisely focused beams of gamma radiation to small targets inside the brain and surrounding structures. The individual beams are weak, and pass through healthy tissue leaving it unharmed. Radiation treatment is only delivered at a single, finely focused point where all 192 beams converge to treat the diseased tissue, while nearby healthy tissue is spared. Click here to learn more about how gamma knife perfexion works.
Gamma Knife Perfexion radiosurgery has many benefits. It’s bloodless, painless, requires no hair removal or head shaving, and has a rapid return to pre-treatment activities with no or very little need for rehabilitative services. This single (one) session outpatient procedure does not require the use of general anesthesia, and is usually covered by most major health insurance companies, including Medicare. Gamma Knife surgery has excellent, long-term well-documented clinical outcomes for a variety of conditions, and has treated over 700,000 patients worldwide.
Gamma Knife radiosurgery treatment is often used in conjunction with surgery, other forms of radiation therapy, and chemotherapy, or it can be used as a primary form of treatment. Patients who cannot or do not wish to undergo surgical procedures may be candidates for Gamma Knife. Gamma Knife treatment can also be used when other treatment methods have failed to control a disease, if there is recurrent disease, or for inoperable disease. Learn more about gamma knife perfexion treatment with our treatment guide.
Malignant Brain Tumors:
- Single and multiple brain metastases (cancer spread to the brain)
- Malignant Glial Tumors (Grade III & IV)
- Nasopharyngeal Carinoma
- Other malignant tumors
Benign Brain Tumors:
- Acoustic Neuroma (Vestibular Schwannoma)
- Trigeminal Schwannoma
- Other Schwannoma tumors
- Benign Glial Tumors (Grade I & II)
- Pituitary Adenoma (Secreting and Non-secreting)
- Pineal Region Tumors
- Glomus Tumor
- Other benign tumors
- Trigeminal Neuralgia (Tic Douloureux / Facial Pain)
- Essential Tremor
- Pain secondary to cancer
- Arteriovenous Malformations (AVMs)
- Cavernous Malformations
- Uveal Melanoma
Current Research Indications:
- Parkinson’s Disease
- Obsessive Compulsive Disorder (OCD)
The Gamma Knife Perfexion can also treat head and neck diseases located in the:
- Nasal cavity
- Lip, mouth, or salivary glands
- Throat, pharynx, or larynx
Most patients are referred to the Gamma Knife program by their doctors. However, some make self-referrals. The Gamma Knife team reviews each patient’s records to determine if Gamma Knife radiosurgery treatment would be appropriate and advantageous. Learn how to prepare for your gamma knife perfexion procedure by clicking here.
Our multidisciplinary Gamma Knife team will review each patient’s:
- Medical and Surgical History
- Clinical Examination information
- Imaging studies, such as MRI, CT and/or PET scans
The Gamma Knife’s success rate is impressive. Supported by more than forty years of clinical research, this radiosurgery tool has met with unprecedented results. Clinical applications continue to grow, and its many benefits as a non-invasive treatment modality continue to make it the treatment of choice for certain clinical conditions. Over 700,000 patients have been treated worldwide. On average, over 60,000 patients receive Gamma Knife treatment each year.
The Gamma Knife or cyberknife allows non-invasive brain ‘surgery’ to be performed with extreme precision while sparing healthy tissues surrounding the targeted treatment area. Also, because neither a surgical incision nor general anesthesia is required, the risks usually involved with open brain surgery, such as hemorrhage or infection, are reduced. Overnight hospitalization may be required and recovery time is minimal. While individual patient outcomes may vary, patients may resume their normal pre-treatment lifestyle within a few days.
Gamma Knife radiosurgery is especially valuable for patients whose neurological disorders require a difficult surgical approach or may be impossible to treat using conventional neurosurgical techniques. Patients of advanced age or in poor medical condition can be at an unacceptably high risk for anesthesia and conventional surgery, making Gamma Knife treatment an ideal solution. Gamma Knife technology also is highly beneficial for patients whose lesions are situated in an inaccessible or functionally critical area within the brain. In addition, the treatment can be used as an adjunct to the care of a patient who has undergone conventional brain surgery, interventional neuroradiology, conventional radiation therapy or chemotherapy.
First, a lightweight stereotactic frame is attached to the patient’s head. Local anesthesia, with conscious sedation controlled by an anesthesiologist, is used before the frame is secured in place. The frame allows for the extremely high level of accuracy during the treatment procedure. The patient then has an MRI imaging study or, in the case of an arteriovenous malformation, angiography may be needed in order to precisely locate the diseased area. Data from the imaging study is transferred into the treatment planning computer. While the patient rests, the treatment team (a neurosurgeon, radiation oncologist and physicist) uses advanced software to determine the treatment plan. This may take up to an hour to complete, depending on the complexity and location of the disease. When the individual treatment plan is completed, the patient is placed on the Gamma Knife couch and precisely positioned. The patient is then moved automatically, head first into the machine, and treatment begins. Treatment typically lasts from 15 minutes to an hour, during which time the patient feels nothing unusual. Following treatment, the patient is automatically moved out of the machine, and the head frame is removed.
Patients do not see or feel the radiation during the actual treatment step of the procedure.
Patients may feel a slight discomfort from the local anesthetic used prior to head frame placement, and have reported feeling pressure for a short time while the pins are inserted to fixate the head frame, but no pain.
Patients remain awake and conscious throughout the entire procedure, and may communicate with the treatment team through the audio and video system in the Gamma Knife Radiosurgery suite.
No, the head is not shaved for Gamma Knife treatment. In rare cases, the treatment may cause some localized hair loss, if the area treated is superficial. Patients should not use any hair or skin products on the day of treatment.
When the treatment is finished, the head frame will be removed. Sometimes there is a little bleeding from where the pins were attached to the head. In this case, gauze and pressure will be applied to stop the bleeding and keep the area clean. A temporary head dressing is placed to keep the pin sites clean. Patients are observed for a short period of time and usually released to go home. Depending on the type of condition treated, some patients may require an overnight hospital stay. Follow up procedures will be discussed with each patient prior to release. It is recommended that the patient take it easy over the next 12 to 24 hours. Pre-Gamma Knife activities can be resumed within a few days.
The effects of Gamma Knife radiosurgery occur over several months to several years, depending on the type of medical condition treated. The treatment goal of radiosurgery with the Gamma Knife Perfexion is control. For tumors, radiation alters the DNA of the tissue being treated so that the cells no longer reproduce, eventually rendering the lesion static. Some abnormalities may shrink, while others simply exhibit no further growth. For vascular disease, the goal of treatment is total obliteration (or occlusion) of the blood flow through the abnormal vessels until they are no longer visible on imaging. The radiation treatment causes the abnormal vessels to swell, eventually cutting off blood flow through them over time. For functional disorders such as trigeminal neuralgia facial pain, the goal of treatment is reduction of and/or freedom from pain and medications. The effectiveness of the treatment is monitored by MRI scans or other forms of imaging at regular intervals.
Early complications may include:
Common side effects:
- Local pain and swelling in the scalp
- Skin reddening and irritation
Delayed complications may include:
- Local loss of hair in superficial lesions
- Local brain swelling in the treatment site
- Local necrosis in the treatment site
- Visual loss (dependent on diagnosis and areas treated)
- Hearing loss (dependent on diagnosis and areas treated)
- Secondary tremors (dependent on diagnosis and areas treated)
Patients typically return to pretreatment activities within a few days. The only restrictions a patient will have are the same he/she had prior to Gamma Knife radiosurgery treatment.
Gamma Knife radiosurgery is reimbursed by most insurance companies, PPOs, and HMOs, including Medicare.
Cost studies have shown Gamma Knife radiosurgery to be less expensive than conventional neurosurgery (open surgery) because it eliminates lengthy post-surgical hospital stays, expensive medication and potentially months of rehabilitation. Importantly, there are virtually no post-surgical disability and convalescent costs with this procedure.
Treatment with the Gamma Knife Perfexion differs from other forms of radiation therapy in a couple of ways. First, the Gamma Knife Perfexion was designed solely to treat the brain, its surrounding structures, and some head and neck diseases, whereas most radiation therapy devices are designed to treat multiple areas of the body. The Gamma Knife Perfexion is a form of stereotactic radiosurgery which uses up to 192 extremely precise beams of radiation to treat small target areas with a very high dose of radiation while sparing adjacent, normal healthy tissue. Other forms of radiation therapy typically use one radiation beam, provide a less conformal treatment, and do not deliver as high of a treatment dose as the Gamma Knife. Treatment with Gamma Knife is performed in a single (one) day treatment session versus other forms of radiation therapy which may require up to thirty or more treatments over several weeks. Gamma Knife treatment also does not typically impede or interrupt ongoing chemotherapy for a primary cancer and typically does not require patients to hold other medications to receive treatment, whereas other forms of radiation therapy might.
We have provided a list of the gamma knife perfexion facts. In case you have additional questions, please contact us at 914-242-8113.