Evidence-based medicine
“Because of its extensive use and enormous amount of supportive data generated, the Gamma Knife is still considered the gold standard.” – Journal of Neurosurgery.
Introduction
Of the stereotactic technologies available for brain radiosurgery, Gamma knife has the best supporting evidence base. This evidence base is superior, not only in the number of articles, but the length of follow-up.
Making sure that patients have been followed up for a sufficient time is important. This is because some of the brain diseases treated with Gamma Knife radiosurgery take time:
- Before the full effect is seen and very importantly
- Before any safety issues emerge.

We at Gamma Knife South Africa have put this guide together to help doctors and patients navigate through large volumes of information that can sometimes be confusing.
Because of their nature, the conditions we treat with Gamma Knife radiosurgery cannot be subjected to the same studies used to test medicines, for example.
Information emerges slowly over time and is reported in multiple studies. Reading one of these studies in isolation may even give the impression studies are contradictory. This is particularly true for those who venture into the volumes of information available about the alternatives to stereotactic and Gamma Knife surgery.
To make sure that we offer patients access to the best treatment, we offer:
- A dedicated healthcare professional portal to give our network of specialists that refer patients to us the most up-to-date and balanced information about the place of the Gamma Knife in the treatment of key conditions.
- A dedicated patient portal for patients who will undergo Gamma Knife treatment at our treatment unit.
- Balanced, accessible information for our patients and their families about Gamma Knife radiosurgery.
The best available research information
Evidence-base medicine uses the best scientific information available about the benefits and risks of Gamma Knife stereotactic radiosurgery so that an informed decision can be made about the best treatment for:
- An individual patient (the doctor) or
- A population (a medical scheme or the government).
This informed decision integrates clinical experience and patient values with the best available research information.
Explosion of medical literature
There has been an explosion of medical literature on Gamma Knife treatment for a range of conditions. Numerous new clinical trials are published daily with many more media articles reporting on them.
Navigating this information for patients and even doctors can be difficult. Therefore, when considering information about Gamma Knife treatment, it is important to consider the following:
- Not all clinical trials are equal and although a well-designed randomised controlled clinical trial (study) is considered the best in general medicine, for practical and ethical reasons they are not always possible
- It is important to weigh up all the studies available and not just the most recent one or the one that has the results that you like.
- Not every patient is the same and your doctor needs to look at the types of patients in the study to see if they were similar to his or her patient before making a decision about treatment.
- Sometimes the results of the studies can be confusing as they give conflicting information, and the risks need to be weighed against the benefits.
- Does the study examine important outcomes? We always ask: Does the clinical study examine outcomes that are important?
Latest evidence
At Gamma Knife South Africa:
- We are involved in a process of interrogating the latest evidence before following it
- We are committed to the ongoing professional development of our team members and specialists, and we facilitate this continuous learning.
Challenges with clinical studies
When factoring in what the latest studies are revealing about Gamma Knife stereotactic radiosurgery, we remain mindful of the common problems with clinical trials and studies. These are outlined below:
01.
When looking at the results of the study it is important to look at whether the study is using the same technology, doses or techniques when proposing treatment for a patient.
02.
For example, studies reporting the outcomes in stereotactic radiosurgery (SRS) may very well have different results because they used different doses or equipment that was not as precise.
03.
Another problem with studies is that they may not measure the right things (outcomes), or they may not follow-up the patients for long enough.
04.
A study needs to have enough people in it (statistical power) to ensure that the results they report are not because of chance but because of the intervention – in this case, Gamma Knife radiosurgery.
05.
It is also possible to select patients who are more likely to respond to treatment and put them in the study group where you want a good outcome. The way this is manged is by blinding, where nobody in the clinical team knows what treatment has been given. However, this becomes challenging when the treatment is surgical, such as with Gamma Knife radiosurgery.
06.
Very often there are very few studies that compare the options available for a patient. In an ideal world, if there are three treatment options, there should be a well-designed study that compares the results of all three studies ‘head-to-head’.
Systematic reviews
Fortunately, there are useful tools that combine information from many clinical studies into one place. These are called systematic reviews which may also include a meta-analysis.
What is important is that the authors of the study report how they found the articles and why they included some and rejected others. In some of the meta-analysis of radiosurgery studies, different doses or measurements are ‘lumped together’ which creates a confusing picture that we at Gamma Knife South Africa do not rely on.
Weighing-up information from other sources
01.
What friends and family say: It is possible to learn a lot from the experience of a person that you know and trust. Their experience of Gamma Knife treatment may be useful to you. At the same time, it’s important to remember that this is one person’s experience that is unique to them. Clinical studies look at a large number of people and can give a better picture of what you can expect.
02.
What your doctor says: There is so much information for your doctor to process and hopefully, she or he adopts an evidence-based medicine approach to propose the best treatment for you. In keeping up with the evidence, the evidence itself can be confusing, which is why there are ongoing studies to provide healthcare professionals with greater clarity.
03.
What the media say: The media tend to be optimistic about advances in medicine, yet often focus on just one study without placing it in the context of all the available evidence. It is important not make decisions based on a single or cluster of media articles that report on just one study; the trends need to be considered.
Benefits of evidence-based medicine
- Promotes consistency of treatment and optimal outcomes
- Helps establish national standards of patient care
- Sets criteria to measure and reward performance-based medical practice