Acoustic neuroma, also known as vestibular schwannoma, is a non-cancerous tumor that develops on the vestibular nerve, which connects the inner ear to the brain. While benign, this tumor can cause a range of symptoms due to its proximity to vital structures in the brain, including hearing loss, balance problems, tinnitus (ringing in the ears), and in severe cases, facial numbness or weakness. If left untreated, acoustic neuromas can grow, pressing on nearby nerves and even the brainstem, which can lead to more serious complications.

Gamma Knife radiosurgery has become a popular treatment option for patients with acoustic neuromas due to its precision, effectiveness, and non-invasive nature. In this blog post, we will discuss how Gamma Knife can be used to treat acoustic neuroma, what patients can expect during the procedure, and the typical outcomes.

What Is an Acoustic Neuroma?

An acoustic neuroma is a slow-growing tumor that arises from the Schwann cells, which form the sheath covering the vestibular nerve. This nerve is responsible for balance and hearing, so when the tumor grows, it can interfere with these functions, leading to symptoms such as:

• Hearing Loss: Often one-sided (unilateral), gradually worsening over time.
• Tinnitus: Ringing, buzzing, or other abnormal sounds in the affected ear.
• Balance Issues: Dizziness or unsteadiness, particularly when moving or walking.
• Facial Numbness or Weakness: If the tumor compresses the facial nerve.

Although acoustic neuromas are not cancerous, their location can pose a threat to neurological functions as they grow. The goal of treatment is to stop the tumor’s growth while minimizing any damage to nearby nerves.

Why Gamma Knife Radiosurgery for Acoustic Neuroma?

Gamma Knife radiosurgery is a preferred treatment option for many patients with small to medium-sized acoustic neuromas or for those who are not good candidates for traditional surgery due to age or medical conditions. Unlike conventional surgery, which involves physically removing the tumor, Gamma Knife delivers precise beams of radiation to the tumor, causing it to stop growing and potentially shrink over time. The surrounding healthy tissue is spared, and the risks of surgery-related complications are minimized.

How Does Gamma Knife Radiosurgery Work?

Gamma Knife radiosurgery uses advanced technology to deliver multiple focused beams of gamma radiation to the acoustic neuroma. The beams converge at the tumor, delivering a high dose of radiation to the abnormal tissue, while minimizing exposure to surrounding brain structures. This precision makes Gamma Knife especially suited for treating tumors located near sensitive nerves, such as the auditory and facial nerves.

The radiation disrupts the tumor cells’ ability to grow and divide, eventually leading to the tumor shrinking or becoming inactive over time.

What to Expect Before the Procedure

Initial Consultation: Before undergoing Gamma Knife treatment, patients will meet with a team of specialists, including a neurosurgeon, radiation oncologist, and medical physicist. This consultation involves reviewing medical history, conducting hearing tests, and assessing MRI or CT scans of the brain to determine the size and location of the tumor. The team will explain the procedure in detail and discuss the potential benefits and risks of treatment.

Pre-treatment Imaging: Detailed imaging is required to create a 3D map of the tumor and surrounding brain structures. This ensures precise targeting of the radiation. MRI scans are commonly used to assess the exact size and position of the acoustic neuroma and to plan the most effective treatment strategy.

Head Frame Placement: On the day of the procedure, a stereotactic head frame will be placed on the patient’s head. This frame ensures that the head remains perfectly still during the treatment, allowing for accurate targeting of the tumor. Local anesthesia is used to numb the areas where the frame is attached, and the process is generally well-tolerated.

In some centers, a frameless mask system may be available, though the traditional head frame remains the most commonly used approach for maximum precision.

What Happens During the Gamma Knife Procedure?

After the head frame is in place, the patient is positioned on the treatment table, and the Gamma Knife procedure begins. Here’s an overview of what to expect:

1. Precise Targeting: The pre-treatment MRI scans are used to guide the Gamma Knife machine. The tumor is carefully mapped, and the machine delivers focused radiation beams to the acoustic neuroma. These beams are individually weak, but they converge at the tumor site, delivering a powerful dose of radiation directly to the abnormal cells.
2. Painless and Non-invasive: The procedure is entirely non-invasive, with no incisions, stitches, or blood loss involved. The patient is awake throughout the procedure and does not feel the radiation. Some patients may receive a mild sedative to help them relax.
3. Duration: The entire procedure usually takes about 30 to 90 minutes, depending on the size and location of the tumor. Once the treatment is complete, the head frame is removed, and patients are allowed to rest before going home.
4. Outpatient Treatment: Since Gamma Knife radiosurgery is non-invasive, patients can usually return home the same day and do not need a hospital stay or prolonged recovery time.

Recovery After Gamma Knife Radiosurgery

Minimal Recovery Time: One of the main benefits of Gamma Knife radiosurgery is the minimal recovery period. Patients can typically resume normal activities within a day or two after the procedure, with no need for prolonged rest or rehabilitation.

Side Effects: Some patients may experience mild side effects following the procedure, including:

• Temporary headache
• Fatigue
• Mild swelling or discomfort at the pin sites where the head frame was attached
• Temporary dizziness or balance issues

These side effects usually resolve within a few days to a week.

Results of Gamma Knife Treatment for Acoustic Neuroma

The goal of Gamma Knife radiosurgery for acoustic neuroma is to stop the tumor from growing, and in many cases, it can also shrink the tumor over time. However, because the effects of radiation take time to develop, the full results may not be immediate. Here’s what to expect in terms of outcomes:

Tumor Control: In about 90-95% of cases, Gamma Knife radiosurgery successfully halts the growth of the acoustic neuroma. This is especially important for patients whose tumors are causing hearing loss, tinnitus, or balance problems.

Tumor Shrinkage: In some cases, the tumor may shrink in size over several months to years following treatment. While the tumor may not disappear entirely, shrinking or stabilizing it can prevent further complications.

Preserving Hearing and Nerve Function: One of the key advantages of Gamma Knife radiosurgery is its ability to preserve hearing and facial nerve function in many patients. Unlike traditional surgery, which carries a higher risk of damaging the auditory or facial nerves, Gamma Knife’s precision minimizes the risk of these side effects.

Follow-up Care: After the procedure, patients will have regular follow-up MRI scans to monitor the tumor and assess the treatment’s success. These follow-ups are usually scheduled every 6 to 12 months for the first few years after treatment.

Long-term Benefits of Gamma Knife for Acoustic Neuroma

1. Non-invasive: There’s no need for open surgery, making it a safer option for patients who want to avoid the risks associated with traditional tumor removal.
2. High Success Rate: Gamma Knife effectively controls tumor growth in the vast majority of patients, with a very low risk of recurrence.
3. Minimal Recovery Time: Patients can return to normal activities quickly, with few side effects and no need for extended rehabilitation.
4. Low Risk of Complications: Compared to open surgery, Gamma Knife radiosurgery poses fewer risks to hearing, balance, and facial nerve function.
5. Outpatient Procedure: Most patients are able to go home the same day, avoiding a hospital stay and the risks of general anesthesia.

Conclusion

Gamma Knife radiosurgery is an excellent treatment option for patients with acoustic neuroma who are seeking a non-invasive approach to managing their condition. With its high success rate, ability to preserve hearing and facial nerve function, and minimal recovery time, Gamma Knife offers an effective and safe alternative to traditional surgery.

For those considering Gamma Knife radiosurgery, partnering with a trusted medical travel facilitator can ensure access to world-class treatment centers, expert neurosurgeons, and seamless coordination of care, providing peace of mind throughout the medical journey. Contact us now!