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Physician Referrals

A physician can directly refer a patient to the Gamma Knife Center by calling (865) 331-4000 and speaking with the Gamma Knife Coordinator, Rick Wyrick.  During the initial call, basic information about the patient will be requested. The patient’s medical history and current condition then will be presented before the Gamma Knife team, who will determine the patient appropriateness for treatment. If deemed appropriate, the patient’s diagnosis schedule will be determined and the patient first will meet with either the neurosurgeon or radiation oncologist. 

If the physician has a preference about the neurosurgeon or radiation oncologist, he or she can call the doctor directly and ask for a consultation or let Rita Latour know during coordination of patient plan.   

Determination of Patient Appropriateness for Gamma Knife Treatment

All Gamma Knife cases are presented at each conference between the Gamma Knife team. Based on the patient’s medical history and current condition, the team will determine if the patient is an appropriate candidate for Gamma Knife treatment.

If one of the Gamma Knife physicians sees a patient for a consult, and the patient’s diagnosis does not lend itself well to Gamma Knife treatment, the consulting physician may call the referring doctor to discuss.

Standard Gamma Knife Indications & Results

Acoustic Neuromas

Benign tumors typically located on or around the 8th cranial nerve

Symptoms

  • Hearing loss in one ear,
  • balance disturbances,
  • ringing in an ear,
  • headaches or facial problems.
  • Usually appear in patients between the ages of 30 and 60 

Typically Referred By

  • Neurosurgeons
  • Neurologists
  • Internal Medicine
  • Primary Care
  • ENTs/ Otolaryngologists

Gamma Knife Benefits

Clinical evidence reports long-term (5-15 years) tumor control rates of 93-100% for tumors less than 3 cm. Pre-radiosurgery hearing can now be preserved in 60-90% of patients. For intracanalicular tumors, hearing preservation can range from 73-100%. Research also supports greater than 95% of patients have preserved facial and trigeminal nerve function after radiosurgery.

Malignant Brain Tumors

Malignant Glial Tumors, Globlastoma Multiforme, Astrocytoma, Chondrosarcoma 

Symptoms

  • Cognitive changes,
  • headaches,
  • balance disturbances,
  • and various other symptoms depending on tumor location    

Typically Referred By

  • Neurosurgeons
  • Neurologists
  • Internal Medicine
  • Primary Care
  • Medical Oncologists
  • Radiation Oncologists

Gamma Knife Benefits

Typically used in the treatment of residual or recurrent tumors. Effective in conjunction with conventional surgery, chemotherapy, and other forms of radiation therapy. Current research suggests using Gamma Knife at the time of tumor progression may lead to longer overall survival.  Precise treatment helps allow for the preservation of adjacent healthy tissue. 

Meningiomas

Typically benign brain tumors, but can be malignant 

Symptoms

  • Headaches,
  • balance disturbances,
  • seizures,
  • personality changes,
  • and various other symptoms depending on tumor location   

Typically Referred By

  • Neurosurgeons
  • Neurologists
  • Internal Medicine
  • Primary Care

Gamma Knife Benefits

For small tumors of 3 cm or less, research supports that approximately 93-98% of patients experience long-term tumor control of 5-10 years defined as tumor shrinkage or nor further tumor growth. Clinical data also supports that the control rate after stereotactic radiosurgery is equivalent to that after surgical resection for Simpson Grade 1 tumors and superior to grade 2 and 3-4 resections. Also effective in treating residual tumor tissue unable to be removed during surgery.  Used in conjunction with conventional surgery for tumors larger than 4 cm.

Metastatic Brain Tumors

From a variety of cancers such as Breast, Lung, Colon, Prostate, Bladder and Melanoma 

Symptoms

  • Headaches,
  • balance disturbances,
  • cognitive changes,
  • weakness or numbness in arms or legs,
  • seizure, and/or
  • unusual vomiting or visual changes

Typically Referred By

  • Neurosurgeons
  • Neurologists
  • Medical Oncologists
  • Radiation Oncologists 

Gamma Knife Benefits

Highly effective treating single and multiple lesions of all primary tumor types. Current research shows local control provided by treatment of metastatic tumors in any brain location exceeds an average of 85%.  Gamma Knife can be repeated if new brain metastases develop. Can be performed alone, or before or after whole brain radiation therapy (WBRT).  Randomized clinical trials show radiosurgery plus WBRT improved local control over WBRT alone. However, level 1 evidence has also shown that approximately 96% of patients treated with radiosurgery plus WBRT are significantly more likely to show a cognitive decline than those treated with radiosurgery alone. Gamma Knife can also be administered while patients are on chemotherapy.

Pituitary Adenomas

Benign tumors on the pituitary gland; Can be both secreting or non-secreting tumors.

Symptoms

  • Hormonal imbalances,
  • fatigue,
  • restlessness,
  • double vision,
  • vision loss,
  • headaches,
  • vomiting or dizziness 

Typically Referred By

  • Neurosurgeons
  • Neurologists
  • Internal Medicine
  • Primary Care
  • Endocrinologists 

Gamma Knife Benefits

Typically used in the treatment of residual or recurrent tumors following surgery. Clinical research supports tumor control rates for both non-secreting and secreting tumors to be between 70-90%. For secretory tumors, research supports approximately 50-60% of cases will achieve endocrine control in 12-60 months after treatment. Can be used as a primary treatment option when surgery is inadvisable.

Trigeminal Neuralgia

Disorder of the 5th cranial nerve on one part or all of one side of the face. Also known as Tic Douloureux.

Symptoms

  • Intermittent, excruciating facial pain typically on one side of the face.
  • Pain is usually felt in the forehead, along the cheek, jaw line or around the gums and teeth. 

Typically Referred By

  • Neurosurgeons
  • Neurologists
  • Internal Medicine
  • Primary Care
  • Oral Surgeons
  • Dentists 

Gamma Knife Benefits

Current literature reports the rate of initial pain relief ranges from 78-94% usually within 1-3 months after treatment. Typically preserves facial sensations and can be repeated if necessary. Non-invasive alternative for patients who are unable to undergo microvascular decompression due to age or other co-morbidities. Helps patients on drug therapies reduce medications.

Vascular Malformations

Arteriovenous Malformations (AVM). A tangle of arteries and veins in the brain.

Symptoms

  • Cerebral hemorrhage,
  • seizures,
  • severe headaches,
  • neurological deficits.
  • Typically found in patients younger than age 40. 

Typically Referred By

  • Neurosurgeons
  • Neurologists
  • Internal Medicine
  • Primary Care 

Gamma Knife Benefits

Can be used as a primary or supplemental treatment option along with surgery or endovascular embolization techniques.  Treated vessels gradually dissolve and eventually close. Complete obliteration of AVMs takes place in approximately 70-90% of patients within 2-6 years of treatment. Residual AVM can be treated again if total occlusion has not occurred.