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Questions for Treating Physician

OBSERVATION

NON-OPERATIVE TREATMENT WATCH & WAIT / WATCH & SCAN
If a patient chooses the observation / watch and wait option (generally reserved for smaller tumors), periodic imaging is required. Following initial diagnosis, a reasonable plan would be to get a new MRI scan in six months.  If there is no growth, the next scan can be done one year later and then on an annual basis.  If there are any new symptoms, your physician should be notified immediately.  These changes could indicate that the tumor is growing more rapidly.  By waiting, there is a risk you could lose part or all of your hearing in the involved ear.   

There are two significant potential pitfalls with observation. First, it is critical that patients are absolutely prepared to insure that they will follow-through with MRIs as planned. Second, it is necessary to review all MRIs over time, rather than comparing any new MRI only to the immediately preceding one. Tumors may grow slowly enough so that no significant change can be seen over the course of one 6 or 12 month period even though there is significant growth over years.
If significant growth does occur during the observation period, active treatment is indicated and you and your physician may decide to choose between one of two therapies: radiation treatment or microsurgical resection.

RADIATION TREATMENT FOR ACOUSTIC NEUROMA
Radiation treatment for acoustic neuromas is typically done using one of several methods via which radiation is focused on the actual tumor. That is, a computer system is used together with MRI data to create a treatment plan by which the tumor receives a high dose of radiation, while surrounding structures receive a low dose. This is referred to as a “stereotactic” technique. Stereotactic radiation therapy, may be referred to as either "stereotactic radiosurgery” or "fractionated stereotactic radiotherapy" depending upon whether the treatment is done in a single session or is broken up over several sessions. This non¬invasive procedure can usually be performed on an outpatient basis.

There are several different ways to deliver the type of focused radiation required for effective treatment of an acoustic neuroma.  Gamma Knife, LINAC, Novalis, XKnife, CyberKnife are all names of specific machines that deliver radiation.  In each case, the beam that radiates the tumor consists of highly charged photons (x-rays or gamma rays); the differences lie in the way they produce the photons as well as the technology they use to focus the beam(s) to the specific area of the tumor.  Proton Beam is a form of radiation treatment that uses a different principle to focus the radiation energy. You should discuss the various options for radiation treatment with your physician.

The goal of radiation treatment for acoustic neuroma is to stop or control tumor growth. The tumor is not removed or eradicated. Radiation is usually used to treat small and medium-sized acoustic neuromas (<2.5 - 3 cm). Radiation works by damaging the DNA inside cells and making them unable to divide and reproduce and by reducing blood supply or nutrients to the tumor. The dose of radiation used is chosen in order to maximize the effectiveness of treatment (chance of tumor control), while minimizing the risk to surrounding structures. In that the nerves involved with the tumor are immediately adjacent, they do receive a dose that is significant but low enough so as to have acceptable risk.

Tumors may continue to grow or swell for a period after treatment. Success of the treatment is eventually determined by the stabilization of tumor growth and in many cases the tumor then shrinks.

QUESTIONS FOR THE RADIATION TREATING MEDICAL PROFESSIONALS
If you have opted for radiation treatment of your tumor, you may want to ask some of the following questions of your radiation therapist, neurosurgeon, or neurotologist. Be sure that you are comfortable with the responses:

  • How long have you been performing radiation treatment of acoustic neuromas? Have any problems emerged in any of your patients?
  • Have you been certified to do radiation for patients with acoustic neuromas?
  • Will this be a one-dose procedure - radiosurgery, or will it consist of several smaller doses - radiotherapy?
  • What type of radiation treatment (e.g., Gamma Knife, LINAC, CyberKnife, Novalis FSR, proton beam, etc.) do you most commonly perform?  What are the advantages of this type of radiation over the others that are available?  
  • Why do you recommend this particular form of radiation treatment over others?
  • Do you expect hearing, balance or ringing in the ear to be potentially altered by radiation treatment?  
  • Do you anticipate that the tumor will swell after treatment?  For how long? If the tumor swells, do you expect there to be any problems? If there are any problems, how would you treat them?
  • What are the long-term side effects of this treatment?  Say 10 years or more?  How will I know if something is changing?
  • Are physicists involved in the planning of your radiation treatment?
  • What symptoms are commonly experienced by your patients after treatment?  How do you define “side effects”?
  • What are the more serious complications such as malignancy, hydrocephalus and others that can happen with treatment and what are the relative frequencies?
  • How many of your patients have experienced continued growth of their tumors following treatment?  How many of your patients have you followed long-term to draw your conclusion? If this happens to me, what would be my best follow-up procedure? Can I have microsurgery, or can I repeat radiation treatment?  
  • After radiation treatment, may I go about my business as before treatment, or are there any special precautions I should take?
  • When and how often should I schedule follow-up MRIs after treatment?  Will I get these MRIs for the rest of my life?
  • Why would you choose radiation for me?


MICROSURGERY FOR ACOUSTIC NEUROMA

Surgery for acoustic neuromas is typically done using an operative microscope, or, occasionally, with the assistance of an endoscope. Decades ago, surgery for acoustic neuroma carried very high risks, including a significant risk of death. While the risks of major complications cannot be eliminated entirely, these risks are now extremely low in the hands of experienced surgical teams using modern equipment and techniques.

After safety, the primary goal of microsurgery is the preservation of function. The highest risks are to the nerves that are inherently involved with the tumor; that is, the facial nerve and the hearing and balance nerve. Both because facial nerve problems are usually considered to be more incapacitating than unilateral hearing loss and because satisfactory hearing results may be very difficult to obtain, facial nerve function is generally prioritized over hearing outcome. Hearing preservation is not always a realistic expectation, especially in cases of larger tumors. While many patients are very dizzy after acoustic neuroma surgery due to the fact that tumors are inherently part of the balance nerve, nearly all patients are able to compensate significantly (and often completely), for the physiologic loss of vestibular nerve function.

Three surgical approaches, translabyrinthine, retrosigmoid, or middle fossa, may be used for resecting acoustic neuromas. The choice of which procedure depends upon tumor size and configuration, hearing status, surgeons’ comfort level and patient choice. Not all surgeons are comfortable with each approach.

Over the past few years, attention has turned to the option of partial tumor resection. This is due to the availability of MRI for follow-up and to the presence of stereotactic radiation as a treatment option for the residual tumor. Generally, partial resection has the greatest role in the treatment of larger tumors, since total resection of these tumors may result in high rates of facial nerve injury and other problems. It should be clear however, that one surgeon’s definition of partial (or subtotal) resection may be quite different than another’s. It may be very difficult to estimate the amount of tumor left intraoperatively and a truly accurate assessment can only be made by follow-up MRI.

NOTE: It's all right to get more then one opinion.  Since acoustic neuromas are benign and slow growing (usually developing over several years), surgery should not be considered an emergency in most cases.  Be cautious of anyone who tries to convince you to rush into surgery before you have taken the time to make an informed decision.


QUESTIONS FOR THE ACOUSTIC NEUROMA SURGEON

If you have decided to have your acoustic neuroma surgically removed, you may wish to ask some of the following questions of your surgeons. Be sure that you are comfortable with the responses:

  • How many acoustic tumors have you removed this month/this year and what specific training in acoustic tumor surgery have you had?
  • What is your total experience in operative cases of acoustic neuroma tumors over what period of time?
  • What microsurgical approach do you recommend for my tumor size, location, age, health and level of hearing? How comfortable are you with each of the surgical approaches?
  • Do you feel that the facial nerve results or the hearing results are more important in the long-term outcome? How do you achieve their preservation and what are your success rates?
  • Do you electrically monitor the facial nerve during surgery?
  • In your experience, when leaving in small pieces of residual tumor on the brainstem or facial nerve, does tumor growth usually stop?
  • For a tumor the size and shape of mine, what have been your results with respect to facial nerve function, both temporary and permanent?
  • What is the likelihood that my remaining hearing will be preserved after this surgery?
  • Do you anticipate total tumor removal with a single operation? If not, what are my follow-up options?  Surgery?  Radiation?
  • Will this surgery be done by a team of physicians with more than one specialty?
  • What has been your rate of surgical complication with respect to stroke, infection, bleeding, cerebral spinal fluid (CSF) leak and headache?
  • When and how often should I schedule follow-up MRIs after treatment?  Will I get these MRIs for up to 10 years?
  • Does your hospital have a neurological intensive care unit?
  • About how many days will I be in the hospital?
  • What follow-up care will I need?
  • How much discomfort should I expect from headaches and from the incision after this surgery?
  • What do you do to minimize post-surgery headaches?  NOTE: If you have a history of headaches, discuss this with your physician.
  • Did you feel comfortable with the surgeon, the information shared, access to a non-biased sample of his/her previous patients?
  • All other things being equal, when can the surgery be scheduled?

 

Acoustic Neuroma Introduction

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