Why do hospitals have particle accelerators? – Pedro Brugarolas


This syringe contains a radioactive form
of glucose known as FDG. The doctor will soon inject its contents
into her patient’s arm, whom she’s testing for cancer
using a PET scanner. The FDG will quickly circulate
through his body. If he has a tumor, cancer cells within it will take up a
significant portion of the FDG, which will act as a beacon
for the scanner. PET tracers such as FDG are among the most remarkable tools
in medical diagnostics, and their life begins in
a particle accelerator, just hours earlier. The particle accelerator in question
is called a cyclotron, and it’s often housed in a bunker
within hospitals. It uses electromagnetic fields to propel
charged particles like protons faster and faster
along a spiraling path. When the protons reach
their maximum speed, they shoot out onto a target that contains
a few milliliters of a type of water with a heavy form of oxygen
called oxygen-18. When a proton slams into one of these
heavier oxygen atoms, it kicks out another subatomic particle
called a neutron. This impact turns oxygen-18
into fluorine-18, a radioactive isotope that can be
detected on a PET scan. In a little under two hours, about half the fluorine will be gone
due to radioactive decay, so the clock is ticking
to get the scan done. So how can fluorine-18 be
used to detect diseases? Radiochemists at the hospital can use
a series of chemical reactions to attach the radioactive fluorine
to different molecules, creating radiotracers. The identity of the tracer depends on what
doctors want to observe. FDG is a common one because the rate at
which cells consume glucose can signal the presence of cancer; the location of an infection; or the slowing brain function of dementia. The FDG is now ready for
the patient’s scan. When a radiolabeled tracer
enters the body, it travels through the circulatory system
and gets taken up by its target— whether that’s a protein in the brain,
cancer cells, or otherwise. Within a few minutes, a significant amount of the tracer has
found its way to the target area and the rest has cleared from circulation. Now the doctors can see
their target using a PET, or positron emission tomography, scanner. The radiation that the tracer emits
is what makes this possible. The isotopes used in PET decay
by positron emission. Positrons are essentially electrons
with positive charge. When emitted, a positron collides
with an electron from another molecule in its surroundings. This causes a tiny nuclear reaction in which the mass of the two particles is
converted into two high-energy photons, similar to X-rays, that shoot out in opposite directions. These photons will then impact an array of paired radiation detectors
in the scanner walls. The software in the scanner
uses those detectors to estimate where inside the body
the collision occurred and create a 3D map of the
tracer’s distribution. PET scans can detect the spread of cancer before it can be spotted with
other types of imaging. They’re also revolutionizing the diagnosis
of Alzheimer’s disease by allowing doctors to see amyloid, the telltale protein buildup that
otherwise couldn’t be confirmed without an autopsy. Meanwhile, researchers are actively
working to develop new tracers and expand the possibilities of what
PET scans can be used for. But with all this talk of radiation and
nuclear reactions inside the body, are these scans safe? Even though no amount of ionizing
radiation is completely safe, the amount of radiation the body receives
during a PET scan is actually quite low. One scan is comparable to what you’re
exposed to over two or three years from natural radioactive sources,
like radon gas; or the amount a pilot would rack up from cosmic radiation after
20 to 30 transatlantic flights. Most patients feel that those risks
are acceptable for the chance to diagnose
and treat their illnesses.

100 thoughts on “Why do hospitals have particle accelerators? – Pedro Brugarolas

  1. In fact, hospitals have another type of particle accelerators… a linear accelerators (LINAC), in an Radiation Oncology area.

    With a LINAC, they could obtain electrons and photons… and then treat cancer. 😊😊😊

  2. By Quantum Tunneling, The Hydrogen Particles are able to form Helium Nuclei. That's how, The Fusion Process works inside a Sun. Helium Itself is a Noble Gas, It Can't hold any Energy. But you know what else can Hold Energy? That's Right Helium 3. Rare on Earth and, Theorized as a Nuclear Fusion. Our Sun is, 75% Hydrogen.

    ————–
    84÷6=14.
    e=mc^2. :P.
    F=Ma.
    F=Force.
    M=Mass.
    A=Acceleration.

  3. Nah, it's for time traveling.
    Doctors send some terminal patients to the future and fix all diseases before sending them back here.
    Trust me, I was one of them.

  4. I've been doing a lot of research into particle physics and radiation (7th grade physics is boring) and I finally found a way to apply what I've learned. Watching a TED-Ed video always makes me feel great.

  5. In 1988 I was 12 years old and started volunteering at my local hospital. No one would explain these questions. Thank you so much. I have waited over 30 years for this very video

  6. So how does it get accelerated? It says it spins but what propels it? And. If I put this in a thunderstorm and hold a big metal chain, will this send dark-matter lightning bolts into me and will I be in a coma for 9 months.

  7. 3:54 Okay testis are not that far apart……
    I wish they are that far apart so we men won't have nut shot issues…

  8. Last few videos were not as good. But this one is completely awesome. I was just waiting for a science video. Well done TED-Ed.👍

  9. Nice vídeo. Just one caveat, it is a serious misconception that no amount of ionizing radiation is completely safe, and it is not based on scientific evidence.

    It is also relevant to know that aside of F-18, produced with accelerators, the most widely used radioisotope for this kind of diagnostics (with tens of millions of procedures per year) is Technetium-99m, which is produced in nuclear reactors.

  10. Great video, however the idea that "no amount of radiation is safe" that you quoted is false, and not a claim that is supported by science. Take a look at the work taking place at the Canadian Nuclear Lab–they run a "mouse house" where they irradiate mice, and they've found that irradiated mice live longer than the control groups that don't receive extra radiation. There's also studied that show a clear threshold for radioactive dose rate below which no detectable effects could be found. The current state of the art is looking into the genes that are switched on or off with exposure to radiation, and there's some neat science there to look at!

  11. This shows you that hospitals are effing rich. Thats why they charge you utill you go homeless or in debt forever…

  12. If you have to put radioactive substances in the body to find symptoms of diseases and infections, i would not consider you a doctor. Check for physical symptoms, like pain, hair loss/discoloration, nail health, weight gain/loss etc. Pain is generally suppressed with pain killers. The rest are considered "beauty" issues. Well guess what beauty does not come without health.

  13. Personally, I think the animation is one of the best parts and pairs very well with what they teach in the videos.

  14. Oh my goodness, I can't believe positron is an ELECTRON with a positive electric charge. I thought that electrons can only have a negative electric charge… But the fact actually changed hahaha

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