Back to OSF HealthCare
Back to OSF HealthCare
Installing the proton beam technology

Proton Beam Technology

How Proton Therapy Works

Proton therapy is an advanced form of cancer treatment that targets and destroys cancer cells with extreme precision. Here's how it works: Protons are tiny particles with a positive charge. In proton therapy, these protons reach a very high speed using a machine called a cyclotron. Once on the move, the protons are directed into a focused beam, which is carefully aimed at the tumor.

What makes proton therapy unique is its ability to deliver radiation with pinpoint accuracy. Unlike traditional radiation therapy, where X-rays pass through the body and can affect healthy tissues both before and after hitting the tumor, proton beams have a special property called the Bragg Peak. This means the protons release most of their energy directly at the tumor site. The beam stops at the tumor, which minimizes damage to surrounding healthy tissue.

The treatment is delivered in sessions to give healthy cells time to recover between doses. Proton therapy is especially beneficial for treating cancers in sensitive areas, such as the brain, spine or near vital organs, where precision is most critical. It's a painless, non-invasive therapy that allows patients to maintain their daily routines, with fewer side effects compared to traditional radiation. 

Proton Beam Therapy
Poton Beam Cyclotron

Cyclotron

Your proton therapy begins in the giant (100 tons) machine called a cyclotron. The cyclotron is where the energy comes from and speeds the protons to over 100,000 miles per second. Because of how fast the protons are moving, they can reach the inside of your body where the cancer cells are located.
Proton Beam Pencil Beam

Pencil Beam

Pencil beam is the name for the beam of protons that targets the cancer cells. It is about the width of a pencil. The pencil beam is what allows the proton therapy to be so precise. The pencil beam is steered by magnets and delivered in layers, which means it can be tailored to the exact shape of your tumor. It travels from the cyclotron through a long tube to reach you.
Proton Beam Gantry

Gantry

The gantry allows the proton therapy to reach any angle. It is a huge piece of equipment that can move 360 degrees. Your doctors will move the gantry to the exact position so that the pencil beam travels straight to the tumor without hitting any other cells.
Proton Beam Imaging

Imaging

The cone-beam CT imaging allows your doctors to see where the cancer cells are. That means they’ll get a real-time picture of where the pencil beam needs to go and how to best position the machine. You’ll be perfectly aligned to make sure that the treatment is maximized.
Proton Beam Treatment Room

Proton Therapy Treatment Room

You’ll be walked into the room by somebody on your care team.

You’ll lie on a table in the middle of the room. The table can move up and down, so you won’t have to do any climbing.

The gantry makes up the walls and floor of the back side of the room. The panels of the gantry can rotate 360 degrees. Once you’re positioned on the table, the gantry will move around you.

There are two imaging panels that come out of the back gantry wall which help your care team take some X-rays once you’re all set up.

The proton is delivered out of the head of the machine. It looks a bit like a computer screen.

Once you’re all set up, you’ll be the only one in the room during your treatment. The room is hooked up with cameras and microphones, so even when your care team isn’t in the room, you’ll still be able to talk to them.

History

Proton beam therapy has been used for decades in scientific research and medical treatment.

Find out more about where and how it started.

1919

Physicist Ernest Rutherford, a Nobel-prize winner, proved the existence of the nucleus in an atom (a theory that was first proposed in 1886 by Eugene Goldstein). He named the positively charged particles within an atom protons.

1932

Ernest Lawrence invented the cyclotron, which could shoot particles at a high rate of speed. The discovery even earned Lawrence a Nobel prize for physics in 1936.

1946

Scientist Robert Wilson proposed the theory that protons could be used to treat cancer differently than photons. By accelerating protons through a cyclotron, cancer cells could be targeted with protons.

1954

The first treatment on a patient using proton therapy was conducted.

1988

TThe U.S. Food and Drug Administration approved the use of proton therapy to treat cancer. Since then, many scientific and technological advancements have improved the success of proton therapy to treat cancer.

2024

Proton therapy is offered at OSF Cancer Institute in Peoria, Illinois – one of less than 40 proton therapy treatment centers in the U.S.