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The concept of
radiosurgery was invented by the Swedish Professor of
Neurosurgery Lars Leksell in 1951. It was he who first used the
word radiosurgery. The idea behind radiosurgery was that it was
more elegant to perform an operation without opening the head.
After much preliminary research Professor Leksell settled on
Gamma Rays as the best agent for performing radiosurgery. The
term was devised as follows. In the opinion of Lars Leksell the
procedure was a form of surgery, hence the use of the term
'surgery'. As it used radiation it was logical to call it
radiosurgery. The subject had a slow start. From 1967 to 1983
there was only one site practising radiosurgery and that was in
Stockholm. Then first in Buenos Aires and then in Sheffield
radiosurgery centres were established. However, radiosurgery
really took off when a Gamma Knife was established in
Pittsburgh. The chief of neurosurgery there holds the Lars
Leksell professorship in radiosurgery. There are now over 200
Gamma Knife radiosurgery centres round the world. |
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Lars
Leksell
The Inventor of
the Gamma Knife
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Why is
it called Gamma Knife?
The definition
Dr. Leksell gave to radiosurgery was a single session radiation
treatment where radiation is delivered with surgical precision.
Surgery is carried out with a knife. Since his machine uses
Gamma rays it was a simple extra step to call it the Gamma
Knife. As the reader can see this 19-ton machine does not look
at all like a knife. But it is the machine’s function not its
appearance, which justifies the use of the term. |
What is Gamma Knife for?
Today safe neurosurgery is much more achievable than
even 20 years ago. Better anaesthesia, improved
lighting and the operating microscope have done much
to improve the safety of neurosurgery. Even so the
brain remains a major challenge for the physician
practising neurosurgery. There are still regions
where neurosurgery cannot reach. The places inside
the brain where there is most risk are the deep
central portions. In addition the skull base (that
part of the skull the brain sits on) is also a
hazardous area.
Danger areas
There are reasons why safe neurosurgery is hard to
achieve at the base of the brain and the central
region. The central part of the brain can be reached
with accuracy today so it is not just the depth that
is the problem. The difficulties are rather related
to the way in which the brain is constructed. It is
a reasonable analogy to suggest that the surface of
the brain is like a computer while the deeper
portions are like the wires. The computer may be
more complex in its nature but its components are
spread out so that a small amount of damage may pass
unnoticed. The central wiring is compressed so that
the wires (nerves) to many parts of the body are all
compressed together in a tight space. This means
that even a minor neurosurgery procedure could have
very marked effects on the patient. Thus the centre
of the brain is a risky area for the surgeon. The
skull base is also risky because parts of it are
inaccessible to neurosurgery. However, the major
difficulties are related to the nerves and blood
vessels, which are in part fixed and are very
delicate and essential for normal function.
Neurosurgery is much more difficult near these
structures. |
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