The type of treatment required may vary with each patient. It is possible that a patient could be treated more than one way. This is why it is so important that once having been diagnosed with an Acoustic Neuroma the matter should be carefully and openly discussed with your Ear, Nose and Throat Specialist. In some instances a recommendation may be made not to proceed with the treatment but to monitor the Acoustic Neuroma over a period of time especially in relation to elderly people.

Until some years ago surgery was the only way to remove this tumour. However, there is now Stereotactic Radiosurgery/Therapy used to treat a number of selected Acoustic Neuroma patients. It is a non-invasive treatment and uses beams of radiation to reduce the tumour.

MICROSURGICAL REMOVAL:- Over the years considerable improvements have been made with regard to surgical techniques. Microsurgical instruments and the operating microscope are routinely used. Damage to the surrounding nerve tissue has been considerably decreased and the mortality rate is extremely low. The facial nerve function is now routinely monitored during surgery, which has reduced the risk of facial nerve injury. Also cochlear monitoring is used during surgery where there is a possibility of preserving the hearing.

There is more than one microsurgical approach that can be used to remove an Acoustic Neuroma. The type of approach is determined after consideration of the patient's age, the size of the tumour and the level of hearing that is present in the affected ear. If the tumour is small, less than I cm or so, and the hearing is good, then it is reasonable to try to preserve the hearing. For tumours that are mostly confined to the internal auditory canal, an approach via the middle fossa may be appropriate.

For larger tumours extending into the posterior fossa but generally less than 2 cm or so, then a retrosigmoid approach may be used.

The first priority is to get the tumour out safely without injury to the patient in terms of life. The second is to preserve nerves to the face physically and also functioning. Thirdly, consideration is given to preservation of hearing. Where the hearing is absent or there is so little worth preserving or the tumour is too large to allow hearing preservation, then retrosigmoid or translabyrinthine approaches can be used. The latter entails drilling out the inner ear or labyrinth for access to the tumour. Preservation to the facial nerve is possible in the removal of most tumours. Final facial nerve function generally follows the size of the tumour with better results in small tumours and slightly worse results for large tumours.

Whatever approach is used the patient is observed in a special care or high dependency unit with careful monitoring for the first one or two post-operative days.

STEREOTACTIC RADIOSURGERY/THERAPY:- Radiosurgery is a once-only treatment. You, the patient, will probably be asked to arrive at the hospital early in the morning, and in most instances you will be allowed to go home at the end of the day when the treatment is completed. You will be fitted with a fixed frame, pins are put in the head to touch the skull bone, a long acting anaesthetic is used for this, so the person wearing the frame all day does not feel it. There may be a heavy feeling or a band of pressure but no actual pain; the pins hold the frame around the head and a localising device is added for the planning C.A.T. Scan. With this type of frame a very accurate treatment can be achieved.

With Stereotactic Radiotherapy, which is generally used for larger tumours, there is more than one treatment. You can get up to 30 treatments with this. The dose on any one day is quite small so any normal tissues in the treated area recover but the dose accumulates in the tumour. A relocatable frame is used for this treatment. It is something like a football mouth guard which goes on over the teeth and another piece of plastic goes around the back, Velcro straps hold the frame very tightly on the head. With both treatments the C.A.T. Scan and the M.R.I. Scan are used. They achieve what is called image fusion. On the computer those responsible for treatment can match the M.R.I, and fuse it to the C.A.T. Scan so they can get both images on the computer screen at the same time and the M.R.I. Scan gives exquisite detail as to what is happening. The C.A.T. Scan has its own advantages too; it is very accurate at describing where something is, whereas the M.R.I. Scan tells them what is occurring. The actual treatment machine has a small nozzle coming out of it, and the radiation rays come out from that nozzle. The machine arcs over the patient's head continually pointing at the tumour so it gives a very concentrated dose on to the tumour and very little on to the surrounding tissues.

The shrinkage of these tumours takes time, about one-third have shrunk in a year, two-thirds at three years and most of them by four years. You have to be patient, some patients want to know how soon they can have an M.R.I. Scan to see what is happening, but you have to give it time, say 12 months. Some of these tumours actually swell a little before they start to shrink, so it is much better to wait and see that there are no symptoms or problems, because these tumours will in time start to shrink again. There is a down side to Radiosurgery, but the risks are relatively well described and acceptable with good rates of hearing preservation and good rates of tumour control.