Performing brain surgery without a scalpel - Hyunsoo Joshua No
-
0:07 - 0:12Every year, tens of thousands of people
world-wide have brain surgery -
0:12 - 0:14without a single incision:
-
0:14 - 0:20there’s no scalpel, no operating table,
and the patient loses no blood. -
0:20 - 0:24Instead, this procedure takes place
in a shielded room -
0:24 - 0:28with a large machine that emits
invisible beams of light -
0:28 - 0:31at a precise target inside the brain.
-
0:31 - 0:35This treatment is called
stereotactic radiosurgery, -
0:35 - 0:39and those light beams
are beams of radiation: -
0:39 - 0:45their task is to destroy tumors by
gradually scrubbing away malignant cells. -
0:45 - 0:49For patients, the process begins
with a CT-scan, -
0:49 - 0:54a series of x-rays that produce
a three-dimensional map of the head. -
0:54 - 1:00This reveals the precise location, size,
and shape of the tumor within. -
1:00 - 1:05The CT-scans also help to calculate
something called "Hounsfield Units," -
1:05 - 1:08which show the densities
of different tissues. -
1:08 - 1:11This offers information
about how radiation -
1:11 - 1:15will propagate through the brain,
to better optimize its effects. -
1:15 - 1:20Doctors might also use
magnetic resonance imaging, or MRI’s, -
1:20 - 1:24that produce finer images of soft tissue,
-
1:24 - 1:28to assist in better outlining
a tumor’s shape and location. -
1:28 - 1:32Mapping its precise position and size
is crucial -
1:32 - 1:36because of the high doses of radiation
needed to treat tumors. -
1:36 - 1:40Radiosurgery depends on the use
of multiple beams. -
1:40 - 1:44Individually, each delivers a low dose
of radiation. -
1:44 - 1:48But, like several stage lights converging
on the same point -
1:48 - 1:53to create a bright and inescapable
spotlight, when combined, -
1:53 - 1:59the rays of radiation collectively
produce enough power to destroy tumors. -
1:59 - 2:02In addition to enabling doctors to target
tumors in the brain -
2:02 - 2:06while leaving the surrounding
healthy tissue relatively unharmed, -
2:06 - 2:10the use of multiple beams
also gives doctors flexibility. -
2:10 - 2:14They can optimize the best angles
and routes through brain tissue -
2:14 - 2:18to reach the target and adjust
the intensity within each beam -
2:18 - 2:20as necessary.
-
2:20 - 2:23This helps spare critical structures
within the brain. -
2:23 - 2:28But what exactly does this ingenious
approach do to the tumors in question? -
2:28 - 2:34When several beams of radiation intersect
to strike a mass of cancerous cells, -
2:34 - 2:38their combined force essentially
shears the cells’ DNA, -
2:38 - 2:41causing a breakdown
in the cells’ structure. -
2:41 - 2:46Over time, this process cascades
into destroying the whole tumor. -
2:46 - 2:52Indirectly, the rays also damage the area
immediately surrounding the DNA, -
2:52 - 2:56creating unstable particles
called free radicals. -
2:56 - 2:58This generates a hazardous
microenvironment -
2:58 - 3:00that’s inhospitable to the tumor,
-
3:00 - 3:04as well as some healthy cells
in the immediate vicinity. -
3:04 - 3:07The risk of harming non-cancerous tissue
is reduced -
3:07 - 3:10by keeping the radiation beam coverage
-
3:10 - 3:14as close to the exact shape
of the tumor as possible. -
3:14 - 3:18Once radiosurgery treatment has destroyed
the tumor’s cells, -
3:18 - 3:21the body’s natural cleaning
mechanism kicks in. -
3:21 - 3:25The immune system rapidly sweeps
up the husks of dead cells -
3:25 - 3:30to flush them out of the body, while
other cells transform into scar tissue. -
3:30 - 3:35Despite its innovations, radiosurgery
isn’t always the primary choice -
3:35 - 3:38for all brain cancer treatments.
-
3:38 - 3:42For starters, it’s typically reserved
for smaller tumors. -
3:42 - 3:44Radiation also has a cumulative effect,
-
3:44 - 3:49meaning that earlier doses can overlap
with those delivered later on. -
3:49 - 3:51So patients with recurrent tumors
-
3:51 - 3:56may have limitations with future
radiosurgery treatments. -
3:56 - 4:01But these disadvantages weigh up
against some much larger benefits. -
4:01 - 4:03For several types of brain tumors,
-
4:03 - 4:07radiosurgery can be as successful
as traditional brain surgery -
4:07 - 4:09at destroying cancerous cells.
-
4:09 - 4:14In tumors called meningiomas,
recurrence is found to be equal, or lower, -
4:14 - 4:17when the patient undergoes radiosurgery.
-
4:17 - 4:19And compared to traditional surgery—
-
4:19 - 4:22often a painful experience
with a long recovery period— -
4:22 - 4:25radiosurgery is generally pain-free,
-
4:25 - 4:28and often requires
little to no recovery time. -
4:28 - 4:32Brain tumors aren’t the only target
for this type of treatment: -
4:32 - 4:37its concepts have been put to use on
tumors of the lungs, liver, and pancreas. -
4:37 - 4:41Meanwhile, doctors are experimenting
with using it to treat conditions -
4:41 - 4:47such as Parkinson’s disease, epilepsy,
and obsessive compulsive disorder. -
4:47 - 4:50The pain of a cancer diagnosis
can be devastating, -
4:50 - 4:53but advancements in these
non-invasive procedures -
4:53 - 4:56are paving a pathway
for a more gentle cure.
- Title:
- Performing brain surgery without a scalpel - Hyunsoo Joshua No
- Speaker:
- Hyunsoo Joshua No
- Description:
-
View full lesson: https://ed.ted.com/lessons/performing-brain-surgery-without-a-scalpel-hyunsoo-joshua-no
Every year, tens of thousands of people have brain surgery without a single incision: there’s no scalpel, no operating table, and the patient loses no blood. Instead, this procedure uses a machine that emits invisible beams of light at a precise target inside the brain. So how exactly does this treatment work? And what does it do to the tumors it targets? Hyunsoo No explains radiosurgery.
Lesson by Hyunsoo Joshua No, directed by Hype CG.
- Video Language:
- English
- Team:
- closed TED
- Project:
- TED-Ed
- Duration:
- 04:57
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Tara Ahmadinejad edited English subtitles for Performing brain surgery without a scalpel |