Apr 28, 2022
One of the most important developments in the history of cancer treatment was radiosurgery, which was a technique that could destroy malignant tissue with exacting precision and without the need for more open forms of surgery.
When attempting to remove or destroy malignant tissue, lesions or tumours, where this cancerous material is will strongly affect what types of treatment are possible or within acceptable boundaries of safety, and no place in the body is more sensitive and precarious as the brain.
Before the development of radiosurgery, if someone suffered from a small lesion or tumour in the brain, surgery could be seen as too risky to attempt, given the chance of complications, and neurosurgeons looked for an alternative.
The man who managed to make a breakthrough, however, was a Swedish neurosurgery specialist by the name of Lars Leksell.
His technique, which he called stereotactic radiosurgery (SRS), was described by Dr Leksell himself as a “single high dose” of radiation, targeted using three-dimensional coordinates to target a certain point within the brain, usually where a small lesion or growth had developed.
Initially, despite being called radiosurgery, the very first stereotactic instrument Dr Leksell attempted to use was a series of electrodes and probes, only replacing them with focused x-ray beams in the early 1950s.
Radiation was an essential part of the process, particularly once multiple narrow beams were focused on a particular point since they could deliver a dose of radiation strong enough to kill targeted tissue whilst protecting healthy brain tissue from unnecessary damage.
Over the next decade, the main evolution of radiosurgery, primarily carried by the work of Börje Larsson and Kurt Linden, was the development of dedicated proton beams to stereotactic radiosurgery, rather than relying on x-rays.
Whilst this was a major step forward from x-rays, there were still issues. Proton beam therapy relies on the use of a synchrocyclotron, a type of particle accelerator that whilst effective, was also too big and too bulky to allow for regular use.
This was when Dr Leksell would help to develop the Gamma Knife at the Karolinska Institute in Stockholm, which was developed to be a relatively compact, simple to use practical tool that a surgeon could themselves use to treat patients.
The initial prototype works in a very similar way to the more advanced Gamma Knife systems used today, with several sources of cobalt-60 radiation being placed in a helmet with slits that were designed to treat a range of pain, behavioural and movement disorders that regular treatments could not.
The second, which used 179 cobalt-60 sources, was used to treat brain tumours, and later units would use 201 cobalt-60 sources, a number that continues to be used to this day as the systems used to focus radiation are more accurate than those used by Dr Leksell.
Beyond cancers, however, the Gamma Knife has become an effective tool for treating diseases that previously required surgical intervention, such as acoustic neurinomas, arteriovenous malformations (AVMs) and pituitary adenomas.
Dr Leksell did not unfortunately live too long into the new era of radiosurgery that he had developed, dying peacefully in the Swiss Alps in 1986 at the age of 78.