Many patients with acoustic neuromas or schwanommas  have hearing function at the time of diagnosis. The goal of any treatmentg surgery or radiation is to treat the tomor and to maintain the hearing. To date, radiosurgical techniques have been focused on conformal irradiation of the tumor, with less attention to inner ear structures and therefore hearing. This study that was published in Neurosurgery (an academic journal) evaluated tumor control and hearing preservation as they relate to tumor volume, imaging characteristics, and nerve and cochlear (inner ear structure0 radiation dose following stereotactic radiosurgery (SRS) using the Gamma Knife.

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Gamma Knife has been instrumental in non-invasive treatment of intracranial diseases for more than 40 years.  These intracranial (inside the skull) lesions include primary brain tumors (including gliomas, pituitary tumors, meningiomas, and acoustic neuromas), and metastatic brain tumors, vascular malformations, and trigeminal neuralgia.  The safety and efficacy Gamma Knife are extensively studied and established.

Gamma Knife has revolutionized our treatment of brain tumors.  Metastatic spread of tumors to the brain has become more common since patients with systemic tumors are treated more effectively and surviving longer.  The chemotherapy prescribed for tumors in other parts of the body generally cannot penetrate the blood-brain barrier.  As such, the brain provides a safe haven for the spread and growth of these tumors. Since most of these lesions are embedded deep inside functional parts of the brain, in the past they have been unaccessible via surgical approaches.  Whole-brain radiation, although sometimes effective, is limited in dose and damages the normal brain substantially.

As such, these patients comprise the majority of those treated with Gamma Knife Raosurgery around the world (138,803).  Many have had multiple lesions, most of which could not be treated surgically. Some had previous whole-brain radiation and were not candidates for re-radiation due to excess cumulative doses. Using Gamma Knife, we have been able to treat each new or recurrent lesion individually.  Moreover, with Gamma Knife precision of better than 0.5mm, the surrounding brain tissue and function were completely spared.

Non-metastatic tumors are also candidates for non-invasive Gamma Knife Surgery.  The surgical approach and aggressive resection of these tumors carry significant risks. Gamma Knife Radiosurgery can be utilized to control the residual tumor after a safe partial resection or even as the primary treatment modality when the tumor size allows.

Complete acoustic neuroma resection is usually a challenging surgical procedure with difficulty preserving adjacent cranial nerve function (CN VII–facial movement, VIII–hearing). Worldwide, more than 36,000 with acoustic neuroma have been treated and studied.  The published data (65 published papers) demonstrate excellent tumor control (>98%) with excellent cranial nerve preservation.

The first meningioma treatment with Leksell Gamma Knife was performed in 1970.  Since then, close to 49,000 patients (17 at Northridge Hospital) have been treated.  The results as reported by more than 50 peer review papers have been exciting.  Gamma Knife Surgery is proven to achieve safe and effective control in both short and long-term follow-up documented for more than eight years.

Another well established and highly utilized function of Gamma Knife has been to treat trigeminal neuralgia.  Since the first treatment case in 1951, more than 25,550 patients have been treated worldwide .  The results have been impressive.

In short, Gamma Knife Radiosurgery is a precise non-invasive surgical tool with more than 0.5mm accuracy that can be delivered to deep targets in the brain on an outpatient basis.  It is attractive to patients who do not want to undergo invasive neurosurgical procedures, do not want a scar, and prefer not to be hospitalized.