Gamma Knife Surgery

Introduction

Gamma Knife surgery is a sophisticated and non-invasive medical procedure that uses focused beams of gamma radiation to treat various conditions within the brain. Despite its name, it involves no incisions; instead, it relies on precision technology to deliver targeted radiation that can effectively manage or eliminate problematic tissues.

History and Development

Gamma Knife surgery was developed in 1967 by Swedish neurosurgeon Lars Leksell. Initially conceived as a tool for functional brain surgery, it has since evolved into a versatile instrument for treating a wide range of neurological disorders. Over the decades, advancements in imaging technology and radiation physics have enhanced the precision and effectiveness of Gamma Knife surgery, making it a preferred option for many patients and clinicians around the world.

How Gamma Knife Surgery Works

Gamma Knife surgery utilizes a machine that emits multiple beams of gamma radiation converging at a single point. Each individual beam is relatively weak and harmless to the surrounding tissues, but when all the beams meet at the target, they deliver a potent dose of radiation. This focused approach allows for the precise treatment of small to medium-sized lesions in the brain without affecting adjacent healthy tissues.

Difference between a frame and a frameless Gamma Knife?

There are two types of Gamma Knife systems available:

• Frame: A fitted metal (usually aluminum) band goes around your head. The frame prevents your head from moving and helps guide gamma rays to a specific area of your brain.
• Frameless: A thermoplastic mask rests over your face, or a net fits around your head. The mask secures to an existing frame on the Gamma Knife table, so your head is completely still.

These pieces of the Gamma Knife machine seem the most intimidating. The frame needs to attach to your skull.

Indications

The goal of Gamma Knife surgery is for the radiation to stabilize, shrink or destroy a tumor or lesion. Gamma Knife surgery can treat small brain abnormalities like:

• Brain tumors (cancerous and noncancerous).
• Blood vessel abnormalities.
• Nerve abnormalities.

Common types of tumors Gamma Knife surgery treats include:

• Acoustic neuroma (vestibular schwannomas).
• Brain metastases.
• Chondrosarcomas.
• Chordomas.
• Craniopharyngiomas.
• Gliomas.
• Meningiomas.
• Paragangliomas.
• Pituitary adenomas.

Some of the most common conditions that Gamma Knife surgery treats include:

• Arteriovenous malformations (AVM).
• Epilepsy.
• Essential tremor or Parkinson’s disease symptoms.
• Trigeminal neuralgia.

The Procedure

The procedure typically follows these steps:

• Preparation: The patient’s head is fitted with a lightweight frame to ensure stability and accuracy. Detailed imaging scans, such as MRI or CT, are then performed to identify the exact location of the target lesion.
• Treatment Planning: Using computer software, the medical team creates a personalized treatment plan, determining the exact coordinates and radiation dose required.
• Radiation Delivery: The patient lies on a treatment couch that slides into the Gamma Knife machine. The radiation beams are directed at the target according to the pre-determined plan. The procedure usually lasts a few hours, during which the patient remains awake and comfortable.
• Post-Treatment: After the procedure, the head frame is removed, and the patient is typically able to go home the same day. Follow-up visits are scheduled to monitor progress.

Applications and Benefits

Gamma Knife surgery is used to treat a variety of conditions, including:

• Brain Tumors: Both malignant and benign tumors can be targeted, including metastases, meningiomas, and acoustic neuromas.
• Vascular Disorders: Conditions like arteriovenous malformations (AVMs) can be treated by causing the abnormal blood vessels to close off.
• Functional Disorders: Conditions such as trigeminal neuralgia, a chronic pain condition, can be alleviated by targeting specific nerve fibers.

Advantages

• Non-Invasive: No surgical incisions are required, reducing the risk of infection and complications.
• Precision: The focused radiation minimizes damage to surrounding healthy tissues.
• Outpatient Procedure: Most patients can return home the same day, with minimal recovery time needed.
• High Success Rate: Gamma Knife surgery has proven effective for many conditions, offering symptom relief and improved quality of life.

Risks and Considerations

While Gamma Knife surgery is generally safe, it does carry some risks, including:

• Radiation Side Effects: Swelling, fatigue, and temporary hair loss at the treatment site may occur.
• Delayed Effects: It can take weeks or months for the full effects of the treatment to become apparent.
• Specific Risks: Depending on the condition being treated, there might be specific risks, such as nerve damage or changes in brain function.

Patients should discuss all potential risks and benefits with their healthcare provider to make an informed decision.

Nursing Care of Patient with Gamma Knife Surgery

Preoperative Care

Patient Education

• Explanation of Procedure: Educate the patient about the Gamma Knife procedure, including the steps involved and what to expect before, during, and after surgery.
• Informed Consent: Ensure the patient understands the risks and benefits and obtain informed consent.

Preoperative Assessment

• Medical History: Review the patient’s medical history, including any previous surgeries, allergies, and current medications.
• Physical Examination: Conduct a thorough physical examination to assess the patient’s overall health status.

Postoperative Care

Monitoring and Assessment

• Vital Signs: Monitor vital signs regularly to detect any deviations from the normal range.
• Neurological Assessment: Perform frequent neurological assessments to identify any changes in brain function.

Managing Side Effects

• Radiation Side Effects: Monitor for swelling, fatigue, and hair loss at the treatment site. Provide appropriate interventions to alleviate these symptoms.
• Delayed Effects: Educate the patient that the full effects of the treatment may take weeks or months to become apparent.

Specific Risks

• Nerve Damage: Monitor for signs of nerve damage and provide appropriate interventions.
• Changes in Brain Function: Be alert for changes in cognitive and motor functions, and take prompt action if necessary.

Patient Support

Emotional Support

• Counseling: Offer counseling services to help the patient cope with anxiety and stress related to the procedure.
• Family Involvement: Encourage family involvement in the patient’s care and recovery process.

Discharge Planning

• Home Care Instructions: Provide detailed instructions on medication management, activity restrictions, and when to seek medical attention.
• Follow-Up Appointments: Schedule follow-up appointments to monitor the patient’s progress and address any concerns.

Gamma Knife surgery can significantly improve the quality of life for many patients. By adhering to these nursing care guidelines, healthcare providers can ensure optimal recovery and support for their patients.

REFERENCES

1. Desai R, et al. (2020). Therapeutic role of gamma knife stereotactic radiosurgery in neuro-oncology.
   https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7023953/
2. Han MS, et al. (2017). Is fractionated gamma knife radiosurgery a safe and effective treatment approach for large-volume (>10 cm ³) intracranial meningiomas?
   https://www.sciencedirect.com/science/article/abs/pii/S1878875016313687?via%3Dihub
3. American Association of Neurological Surgeons. Stereotactic Radiosurgery. https://www.aans.org/en/Patients/Neurosurgical-Conditions-and-Treatments/Stereotactic-Radiosurgery. Last reviewed 12/3/2021.
4. DeAngelis LM, Wen PY. Primary and Metastatic Tumors of the Nervous System. In: Jameson J, Fauci AS, Kasper DL et al, eds. Harrison’s Principles of Internal Medicine. 20th ed. McGraw-Hill, 2018.
5. Jang CK, Jung HH, Chang JH, et al. Long-Term Results of Gamma Knife Radiosurgery for Intracranial Meningioma (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4656885/). Brain Tumor Res Treat. 2015 Oct; 3(2):103–107.
6. National Library of Medicine (U.S.). Stereotactic radiosurgery – Gamma Knife. https://medlineplus.gov/ency/article/007577.htm. Last reviewed 7/17/2022.
7. Omay SB, Baehring JM. Common Tumors of the Nervous System. In: Salardini A, Biller J, eds. The Hospital Neurology Book. McGraw-Hill, 2016.
8. Radiologic Society of North America. Gamma Knife. https://www.radiologyinfo.org/en/info/gamma_knife). Last reviewed 8/30/2023.
9. Ramayya AG, Sinha S, Grady M. Neurosurgery. Brunicardi F, Andersen DK, Billiar, et al, eds. Schwartz’s Principles of Surgery. 11th ed. McGraw-Hill, 2019.

Stories are the threads that bind us; through them, we understand each other, grow, and heal.

JOHN NOORD

Connect with “Nurses Lab Editorial Team”

I hope you found this information helpful. Do you have any questions or comments? Kindly write in comments section. Subscribe the Blog with your email so you can stay updated on upcoming events and the latest articles.