It’s described as ‘brain surgery - without the knife’.
Stereotactic radiosurgery, also known as Gamma Knife, can be used to treat tumours, abnormal collections of blood vessels in the brain, epilepsy and pain disorders such as the facial nerve condition trigeminal neuralgia.
The treatment uses a focused array of 201 intersecting beams of controlled, carefully measured gamma radiation to treat lesions within 0.1mm of precision.
Unlike open surgery, patients are usually treated as a day case, and the treatment is less invasive.
Sheffield is home to The National Centre for Stereotactic Radiosurgery, based at the Royal Hallamshire Hospital, and has treated over 12,000 people from the UK and even around Europe - including children.
Centre director Dr Matthias Radatz, a consultant neurosurgeon specialising in radiosurgery, said: “Basically it is brain surgery without the knife.
“Patients are treated with local anaesthetic, mostly as a day case - after-care is minimal and they often return to work the same week.”
Sheffield has three Gamma Knife machines, the most of any UK centre, and had the first in Europe outside Sweden when it was launched in 1985.
Then it was seen as almost ‘experimental’, but now it is often the primary treatment for all kinds of conditions.
“It is increasingly replacing the need for open surgery,” said Dr Radatz, who has been involved with over 2,500 patient treatments.
“Now we have the data available to show that it is safe and it is doing the job with less complications.
“It’s a very calculable dose of radiation because you can measure exactly how much it gives you.”
Patients undergoing Gamma Knife surgery first have a metal frame fixed to their skull under local anesthetic. Neurosurgeons specialising in the field are involved to explain the risks which are dependant on the condition being treated.
The frame is vital to help map out the brain and exact location of abnormalities in 3D - and scans are also undertaken to help with this.
A planning team then carefully draw up an individual treatment plan of incredible accuracy using calculations and don’t begin the therapy until it is exactly right.
Dr Radatz added: “I compare it being like an architectural plan on a drawing board, only when everybody is happy do we decide to finally go ahead with the treatment.
“There is very little room for error.”
During the actual treatment patients are placed inside the machine wearing the frame for between 30 minutes to several hours, depending on the size of their abnormality.
The treatment can continue to work for years - with cases known of tumours still shrinking a decade afterwards.
The Star’s reporter Ellen Beardmore had Gamma Knife treatment in May on the remnant of a benign brain tumour.
A 12-hour operation removed most of the life-threatening acoustic neuroma last December.
The 26-year-old, of Hunters Bar, said: “I was in the machine for just over an hour but I could have been lying down at home - I couldn’t feel or hear anything different.
“I was amazed and relieved to hear from the staff how precise the machine was, especially as my tumour is quite an odd shape to treat.
“The frame was the worst bit because it was uncomfortable to wear.
“Afterwards I had a headache, and was tired for a couple of days.
“But compared to brain surgery last year, where I spent eight days in hospital and needed several weeks off work, it was a world of difference.”