-
Not Synced
Every year, tens of thousands of people
world-wide have brain surgery
-
Not Synced
without a single incision:
-
Not Synced
there’s no scalpel, no operating table,
and the patient loses no blood.
-
Not Synced
Instead, this procedure takes place in a
shielded room
-
Not Synced
with a large machine that emits invisible
beams of light
-
Not Synced
at a precise target inside the brain.
-
Not Synced
This treatment is called stereotactic
radiosurgery,
-
Not Synced
and those light beams are
beams of radiation:
-
Not Synced
their task is to destroy tumors by
gradually scrubbing away malignant cells.
-
Not Synced
For patients, the process begins with
a CT-scan,
-
Not Synced
a series of x-rays that produce a
three-dimensional map of the head.
-
Not Synced
This reveals the precise location, size,
and shape of the tumor within.
-
Not Synced
The CT-scans also help to calculate
something called ‘Hounsfield Units’,
-
Not Synced
which show the densities
of different tissues.
-
Not Synced
This offers information about how
radiation
-
Not Synced
will propagate through the brain,
to better optimize its effects.
-
Not Synced
Doctors might also use magnetic resonance
imaging, or “MRI’s,”
-
Not Synced
that produce finer images of soft tissue,
-
Not Synced
to assist in better outlining a
tumor’s shape and location.
-
Not Synced
Mapping its precise position and size is
crucial
-
Not Synced
because of the high doses of radiation
needed to treat tumors.
-
Not Synced
Radiosurgery depends on the use
of multiple beams.
-
Not Synced
Individually, each delivers a low dose
of radiation.
-
Not Synced
But, like several stage lights converging
on the same point
-
Not Synced
to create a bright and inescapable
spotlight, when combined,
-
Not Synced
the rays of radiation collectively
produce enough power to destroy tumors.
-
Not Synced
In addition to enabling doctors to target
tumors in the brain
-
Not Synced
while leaving the surrounding healthy
tissue relatively unharmed,
-
Not Synced
the use of multiple beams also
gives doctors flexibility.
-
Not Synced
They can optimize the best angles and
routes through brain tissue
-
Not Synced
to reach the target and adjust the
intensity within each beam as necessary.
-
Not Synced
This helps spare critical structures
within the brain.
-
Not Synced
But what exactly does this ingenious
approach do to the tumors in question?
-
Not Synced
When several beams of radiation intersect
to strike a mass of cancerous cells,
-
Not Synced
their combined force essentially
shears the cells’ DNA,
-
Not Synced
causing a breakdown
in the cells’ structure.
-
Not Synced
Over time, this process cascades into
destroying the whole tumor.
-
Not Synced
Indirectly, the rays also damage the area
immediately surrounding the DNA,
-
Not Synced
creating unstable particles
called free radicals.
-
Not Synced
This generates a hazardous
microenvironment
-
Not Synced
that’s inhospitable to the tumor,
-
Not Synced
as well as some healthy cells
in the immediate vicinity.
-
Not Synced
The risk of harming non-cancerous tissue
is reduced
-
Not Synced
by keeping the radiation beam coverage
-
Not Synced
as close to the exact shape
of the tumor as possible.
-
Not Synced
Once radiosurgery treatment has destroyed
the tumor’s cells,
-
Not Synced
the body’s natural cleaning
mechanism kicks in.
-
Not Synced
The immune system rapidly sweeps
up the husks of dead cells
-
Not Synced
to flush them out of the body, while
other cells transform into scar tissue.
-
Not Synced
Despite its innovations, radiosurgery
isn’t always the primary choice
-
Not Synced
for all brain cancer treatments.
-
Not Synced
For starters, it’s typically reserved for
smaller tumors.
-
Not Synced
Radiation also has a cumulative effect,
-
Not Synced
meaning that earlier doses can overlap
with those delivered later on.
-
Not Synced
So patients with recurrent tumors
-
Not Synced
may have limitations with future
radiosurgery treatments.
-
Not Synced
But these disadvantages weigh up
against some much larger benefits.
-
Not Synced
For several types of brain tumors,
-
Not Synced
radiosurgery can be as successful as
traditional brain surgery
-
Not Synced
at destroying cancerous cells.
-
Not Synced
In tumors called meningiomas,
recurrence is found to be equal, or lower,
-
Not Synced
when the patient undergoes radiosurgery.
-
Not Synced
And compared to traditional surgery––
-
Not Synced
often a painful experience with
a long recovery period––
-
Not Synced
radiosurgery is generally pain-free,
-
Not Synced
and often requires little
to no recovery time.
-
Not Synced
Brain tumors aren’t the only target for
this type of treatment:
-
Not Synced
its concepts have been put to use on
tumors of the lungs, liver, and pancreas.
-
Not Synced
Meanwhile, doctors are experimenting
with using it to treat conditions
-
Not Synced
such as Parkinson’s disease, epilepsy,
and obsessive compulsive disorder.
-
Not Synced
The pain of a cancer diagnosis can be
devastating,
-
Not Synced
but advancements in these non-invasive
procedures
-
Not Synced
are paving a pathway
for a more gentle cure.