The Motivation That Made Gamma Knife Radiosurgery Possible

radiotherapy centre - Gamma Knife Radiosurgery

People entering the radiotherapy centre today for precise treatment for brain lesions and tumours know that the treatment they are set to receive involves no incisions, leaves only the marks of the metal guide frame and will generally give them the opportunity to go home afterwards.

This is all possible thanks to stereotactic radiosurgery, which is itself made possible thanks to the Gamma Knife method and its inventor Lars Leksell.

Instead of a single focused beam of radiation, the Gamma Knife uses hundreds of beams that converge onto a single point, maximising the effect but minimising any damage to surrounding tissue.

Professor Leksell was a perfectionist, famously noting that no tool is “too refined” when it comes to treating the human brain and working tirelessly to perfect his methods for the rest of his working life.

However, whilst his methods and theory were exceedingly precise, his motivation for pursuing radiosurgery was far simpler; he sought out a more beautiful form of surgery.

Bloodless Surgery

Were it not for a car accident, Professor Leksell would have become a lawyer or literary critic. 

However, the passion of the doctors who treated him and the fascination he had for their methods led him to pursue medicine at the age of 20.

Initially, he struggled to find a focus for his ambitions, until he saw the work of Herbert Olivecrona, the head of neurosurgery at the Seraphim Hospital, Stockholm and the man who would ultimately train him.

However, whilst he had a great appreciation for Professor Olivecroner, he had a deep, multifaceted aversion to neurosurgery as it existed at this point in history.

Whilst neurosurgery had existed since the 1870s, it was still a procedure that relied a lot on somewhat invasive surgery without the aid of CT scans to aid in treatment planning.

It also required exceptionally lengthy recovery times; the modern average time in hospital for a craniotomy is over two weeks.

Professor Leksell had an aversion to blood and to the strong smells found in the operating theatre, and with the traumatic nature of invasive surgery he wanted to see if there was another, more refined, elegant way to perform brain surgery.

His son, Dr Dan Leksell, later claimed that his father wanted surgery to be beautiful.

The first step of this process was the development of a precise, sharp set of double-action forceps still known in operating theatres today as Leksells.  

The second was to redevelop a surgical process that had lain dormant for decades.

A New Stereotactic Frame

Stereotaxy, or the navigation of the brain through a precise set of coordinates, was first devised by Victor Horsley and Robert Clark, who in 1908 used an apparatus that relied on Cartesian coordinates to precisely map animal brains. It is believed to have never been used on humans.

By the end of the Second World War, interest had resumed in the concept of stereotactic neurosurgery, with Ernest Spiegel and Henry Wycis adapting the Horsley-Clark frame in combination with more advanced medical imaging to work with human beings.

Professor Leksell, already curious about the potential for the stereotactic method and having visited the latter at Temple University, Philadelphia, modified the concept of the stereotactic frame to use polar coordinates instead, which was more flexible and considerably easier to use.

However, he was not interested in using it to improve the accuracy and minimise the invasion of conventional surgery but instead used it to develop an entirely non-invasive process.

He also devised a method to adapt X-ray images into the target coordinates for his frame through the use of concentric circles, although unlike many of his other inventions surgeons found it too difficult to rely on. He also innovated the use of ultrasound in neurosurgery.

As well as improving this accuracy, he proposed that a series of small radioactive beams focused to a point would provide the power to destroy a lesion without damaging the surrounding tissue.

As a perfectionist, he kept working on making the frame and the beam more powerful, smaller and easier to use.

His original radiosurgery device, using a synchrocyclotron, was not precise enough for Professor Leksell, given his principle that no tool was too precise for the brain. It was also too awkward and complex for any other surgeon to use consistently.

Its relatively complete form was the Gamma Knife, which allowed for far more precision and versatility, ultimately becoming increasingly used for diseases that previously required the use of invasive neurosurgery.

Professor Leksell continued to practise until 1974 when he was 67. He passed away peacefully at the age of 78 in 1986 in the Swiss Alps.