The gamma knife radiosurgery also known as stereotactic radiosurgery is an advance radiation therapy used to treat brain tumors, abnormal blood vessels formations such as arteriovenous malformations, epilepsy, trigeminal, neuralgia, some other neurological problems and brain abnormalities. Gamma knife radiosurgery is a non – invasive surgery that does not involve any knife or incision instead uses beams of high dose of radiation precisely focused on its target with minimal or no effect on surrounding healthy tissues. It is safer and best suitable for the patients who have:
• Complex tumors or lesions which are hard to reach by traditional surgical methods.
• Patients not enough healthy for undergoing conventional surgical treatments.
• Patient who prefer less invasive treatment.
This procedure is not the best option for patient who needs immediate therapy or treatment as it acts slowly over time.
The gamma knife or stereotactic radiosurgery uses multiple beams of radiation covering from all three dimensions to focus on targeted tumor using high doses of radiation delivered to that volume successfully by moving the patients in sub-millimeter increments with the help of advanced robotic technology. The medical team for performing this surgery consists of all specially trained medical physicist, anesthesiologist, radiation therapist, radiation oncologist and neurosurgeon.
Before the gamma knife radiosurgery, patients would need to do possible blood tests, physical health examination and some other diagnostic tests to ensure whether he or she is suitable for the surgery or not. Patient should also notify to the doctor:
• if they are sensitive or allergic to any medications or any anesthetic agents.
• if they are taking any prior or ongoing medicines. • history of bleeding disorder or taking any anti coagulant medicines.
• If the patient already has any implants such as pacemaker, artificial heart valve, eye or ear implants stent etc.
In gamma knife radiosurgery, patient is given a light sedation and local anesthesia to secure a head frame to the patient’s head. The box shaped head frame is placed precisely by fastening it to the patient’s skull with the help of pins specifically designed for this purpose and in order to keep the head from moving during the surgery. Once it is placed patient undergoes an MRI or CT scan in order to locate the lesion inside the patient’s head. A computer system is used to devise a treatment plan while the patient rests which can take 30 to 90 minutes depending on the location of the target. After treatment plan is completed, patient is placed with his/her head precisely positioned on the gamma knife table for the surgery. After being positioned properly, helmet type equipment with hundreds of holes in it is placed over the head frame which directs and focuses the radiation beams on the targeted lesion. The patient is moved automatically into the machine during the surgery. This can take 20 minutes to 2 hours of time depending on the type and area of the tumor or lesion during which patient cannot feel any pain or unusual discomfort.
After the completing the treatment, head frame is removed and small adhesive bandages are applied where it was placed. Mostly one treatment is required and patient can go back or may need to stay for a night at the hospital for observation as per the health condition. In some cases, patients may feel mild headache or discomfort that can be treated with medicines. Patient is refrained from strenuous activity for next 24 hours. He or she can wash hair with mild shampoo without scrubbing the pin sites where the frame was placed to avoid bleeding or any infection. Physician should be informed immediately if the patient is having severe headache, weakness, numbness, blurred vision or seizures.
The results of gamma knife surgery are mostly good with lower complication rates. Some of the advantages are:
1. Minimum risk and damage to the surrounding healthy tissue and structure.
2. Less expensive than conventional neurosurgery.
3. Less pain and discomfort for patients
4. No infection or hemorrhage as no incisions is made.
5. Short hospital stay and patient can resume normal activities.
Apart from the advantages, there can be some side-effects or complications involved in this surgery:
1. Tiredness or fatigue – patient may feel tired for few weeks after the surgery.
2. Swelling – post treatment swelling in the brain. This is visible usually 6 months after the treatment and doctor may prescribe anti-inflammatory medicines to prevent it.
3. Scalp problems – itchy and red scalp where the frame was attached. In rare cases, patient may lose a small amount of hair if the treatment done right under the scalp.