Gamma Knife therapy is an advanced form of radiation therapy. It is primarily used to treat brain tumors. The treatment is noninvasive, so no incision is necessary. Gamma Knife therapy is a safe and highly precise technique.
Compared to other forms of radiation therapy, Gamma Knife therapy usually requires only a single treatment session, which lasts one day. It can be performed on an outpatient basis.
Here you can find more information and specialists in Gamma Knife therapy.
For which conditions is this treatment suitable?
Gamma Knife therapy is a form of radiation therapy. It is used to treat brain tumors or vascular malformations. The treatment is considered very safe.
Doctors use Gamma Knife therapy when they cannot reach the target area using conventional methods. Gamma Knife therapy is also used when patients are not stable enough to undergo lengthy surgeries.
Specialists in Gamma Knife therapy include radiation oncologists, neuro-oncologists, and radiosurgeons.
Gamma Knife therapy is used to treat the following conditions:
- Brain tumors and brain metastases
Radiosurgical treatment is possible for both benign and malignant tumors. Gamma radiation destroys the DNA (genetic material) in the tumor cells. The goal is not to remove the tumor, but to stop its growth. The tumor’s volume decreases over time following radiation treatment.
- Pineal tumors
The pineal gland is a gland at the base of the brain that plays an important role in hormone regulation. Tumors of the pineal gland lead to metabolic disorders and reduced or increased hormone production. Gamma Knife therapy can shrink such tumors.
- Schwannomas
Schwannomas are benign growths that affect the auditory and vestibular nerves. Pressure on the nerve causes dizziness, hearing loss, or tinnitus. The face or facial muscles may also be affected. With Gamma Knife therapy, doctors can successfully halt the spread of these tumors.
- Cerebral Vascular Malformations
Cerebrovascular diseases are abnormal formations of blood vessels (arteries and veins) in the brain. For example, additional connections between arteries and veins can cause smaller vessels to receive insufficient blood flow. Gamma Knife therapy destroys such vascular connections and restores normal blood flow.
- Neuralgias
Trigeminal neuralgia can affect one or both sides of the face. Those affected suffer from stabbing pains in the forehead, cheeks, or jaw area. Radiation therapy provides patients with relief within a few days to several months.
Radiosurgical treatment with the Gamma Knife is performed on an outpatient basis or during a short inpatient stay @ ATRPhoto /AdobeStock
Treatment Procedure
Before radiation therapy begins, doctors conduct detailed examinations of the tumor or the malformed blood vessels. Only then can they plan the radiosurgical treatment.
- For the preliminary examinations, doctors rely on computed tomography (CT) or magnetic resonance imaging (MRI). If doctors use a contrast agent during the examination, they inject it through a venous catheter.
- Based on the available test results, radiation oncologists can calculate the necessary radiation dose. They determine the area of the brain to be treated and the alignment of the individual beams.
- These steps are computer-controlled. The doctor transmits the data directly to the radiation therapy unit. The patient lies down during radiation therapy. They are moved into the radiation therapy machine on a treatment table or in a bed. The head frame is then secured to the machine.
- To stabilize the head during treatment and precisely focus the individual beams, the oncologist attaches a lightweight stereotactic frame. Doctors secure this frame with four pins under local anesthesia. General anesthesia is not usually necessary for patients undergoing this treatment. However, patients are given a mild sedative if they wish.
The treatment lasts between one and five hours. If the treatment takes longer, the doctor administers IV fluids to the patient to stabilize their circulation.
During radiation therapy, the patient can communicate with the doctors via a microphone. The treatment is silent and painless.
Doctors painlessly attach a lightweight frame to the skull under local anesthesia @ Monkey Business /AdobeStock
Side Effects and Risks of Gamma Knife Therapy
Since Gamma Knife therapy is a non-invasive treatment method, the risks are lower than with open brain surgery.
Side effects that occur immediately after treatment are usually short-lived and disappear after a few days to weeks.
If headaches, nausea, or vomiting occur immediately after radiation, the doctor will treat the symptoms with medication.
There may be slight bleeding at the site on the head where the frame was attached. The patient can eat and drink immediately after treatment.
Common side effects include:
- Nausea or vomiting
- Headaches
- Fatigue
- An itchy sensation on the scalp
- Swelling of the irradiated brain tissue
- Swelling or redness of the scalp
- Mild hair loss in the irradiated areas
- In very rare cases, neurological symptoms have been reported as a long-term effect.
Prognosis for Gamma Knife therapy
The prognosis for Gamma Knife radiation therapy depends on the underlying condition and the patient’s overall health.
Doctors generally achieve good results with Gamma Knife therapy:
- The volume of benign tumors shrinks within one to two years.
- Malignant tumors often shrink rapidly.
- The closure of abnormal brain vessels also takes up to two years or longer.
- Pain management for neuralgia shows results within a few months.
Conclusion
Gamma Knife therapy is a safe and precise method of radiation therapy. Doctors currently use it to treat brain tumors. Compared to open brain surgery, the risks are low.
The radiation itself is controlled by a computer. The latest devices are called CyberKnife and are based on robotic technology. Doctors use them to treat tumors throughout the body. There are now more than ten of these devices in oncology centers across Germany.
It is important for the patient to attend regular follow-up appointments so that the doctor can monitor the success of the treatment and the progression of the disease.
