Gamma Knife South Africa

Gamma Knife stereotactic radiosurgery

for trigeminal neuralgia

Overview

Medical management with medication is the first line of treatment for trigeminal neuralgia. Patients whose pain is not controlled with medicines may benefit from surgical interventions including Gamma Knife stereotactic radiosurgery.

The primary goal of Gamma Knife radiosurgery is to provide optimal pain control whilst avoiding loss of sensation on the face (hypesthesia) or keeping it to an absolute minimum.

Patients and their treatment team need to weigh up achieving pain control using Gamma Knife treatment against some loss of sensation on the face that can occur.

Gamma Knife surgery

How Gamma Knife radiosurgery works

With Gamma Knife surgery, a multidisciplinary team, uses computer imagery to direct a precisely focused beam of high-dose radiation to the trigeminal nerve. This causes a lesion (something like a scar) to form on the nerve, which eventually disrupts the transmission of pain signals to the brain.

Pain relief after Gamma Knife surgery occurs gradually. If pain is not controlled, the procedure can be repeated.

The main advantage of Gamma Knife radiosurgery over the traditional surgical approach is that there is only partial facial weakness. With the surgical approach patients can have total hypesthesia or total loss of sensation in the face. Factors that can impact on the effectiveness of Gamma Knife radiosurgery include previous treatments:
  • Open microvascular decompression
  • Previous surgical treatment on the same side or atypical trigeminal neuralgia.

Research1 indicates that as many as 96 % of trigeminal neuralgia patients experience pain relief within a few weeks after their Gamma Knife procedure. Just2 over 90 % of patients will not need another surgery within the first year. This does drop to 67.7 % at 10 years and remains at this level until 14 years.

The majority of the patients say that their quality of life improved after Gamma Knife radiosurgery and that the hypesthesia or loss of sensation on the face, when present, was a good trade-off for pain relief.

One in two patients will still need some medication to manage any pain but the doses are much lower and manageable.

Research has shown that following Gamma Knife radiosurgery:

The Marseille Technique – Gamma Knife outcomes improved

Early Gamma Knife treatment used a radiation dose of 80 gray but after a landmark study by a French neurosurgical research unit, headed up by Dr. Jean Regis, this has been increased to 90 gray. This is called the Marseille Technique which targets the middle of the trigeminal nerve as opposed to the root entry of the earlier technique. Targeting the middle of the nerve (or the cisternal segment) is safer and has a lower risk of damage to the surrounding sensitive tissue. Dr. Jean Regis, is Professor of Neurosurgery and head of the Radiosurgery Department at Aix Marseille University in Marseille, France. As a result of this breakthrough research, outcomes of Gamma Knife radiosurgery were improved from 20123 onwards. 4974 patients were followed for 12 years after their Gama Knife surgery:
  • 92 % had complete or significant relief from pain at one year
  • 80 % had relief at 5 years and
  • 68 % had relief at 10 years.
The majority of patients with good efficacy (or effectiveness) of radiosurgery had no loss of sensation in the face.

Gamma Knife radiosurgery versus traditional surgery

The advantage of Gamma Knife radiosurgery over the traditional surgical approach is that, if patients develop hypesthesia or loss of sensation on the face, it is only partial.

With the surgical approach patients can have total hypesthesia or loss of sensation on the face.