What is Proton Therapy
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The History of Proton Therapy

The History of Proton Therapy

History of Proton Therapy                                                                                                                    

Proton Therapy, or Proton Beam Therapy, is a type of particle radiation therapy that has been used to treat cancer for nearly 60 years. A beam of protons is directly targeted at the diseased tissue while minimizing radiation exposure to the surrounding healthy tissue. The first suggestion of this discipline was backed in 1946 by physicist Robert R. Wilson. Almost a decade later, Berkeley Radiation Laboratory treated the first human patient using a particle accelerator designed for physics research. This breakthrough created the momentum needed for universities around the nation to look into proton therapy.

As of 2017, more than 130,000 people worldwide have received proton therapy at centers in Europe, Asia and the United States.


German physicist W.C. Roentgen discovers X-rays, making detection of tumors in the body much easier and non-invasive. Roentgen later wins the Nobel Prize in Physics for this discovery (1901).


William Henry Bragg discovers the Bragg Peak. When a fast, charged particle moves through matter, it ionizes atoms of the material and deposits a dose along its path. A peak occurs because the interaction cross section increases as the charged particle's energy decreases.


British physicist Ernest Rutherford demonstrates the existence of protons (elementary particles found in atoms; atoms are made of subatomic particles called protons, neutrons and electrons). (Pictured)


American physicist Ernest O. Lawrence invents the cyclotron, a machine used in proton therapy, which accelerates charged particles to high energy levels. He receives the Nobel Prize in Physics in 1939.


The first clinical use of X-ray radiation therapy is carried out for the treatment of a patient with leukemia at the University of California at Berkeley. Congress passes the National Cancer Institute Act that authorizes annual funding for cancer research in the United States.


American physicist Robert Wilson publishes "Radiological Use of Fast Protons" (Radiology 1946:47:487-91), a study that suggested protons could be used to treat cancer because they are capable of delivering an increased dose of radiation to a tumor while simultaneously decreasing radiation exposure to surrounding healthy tissue, and established the fundamental tenets and techniques that are being followed today at proton therapy facilities around the world.


The first proton therapy experiments are conducted at the University of California at Berkeley. Tumors are effectively removed from the chest and lungs of animals.


The University of California at Berkeley treats the first human patient with protons. Patients are treated with protons at other research institutions, including Harvard University in Boston.


Dr. James M. Slater and his colleagues developed the world’s first computer-assisted treatment planning system. This system allowed the physician to define the patient’s anatomy more precisely and to demonstrate the actual distribution of radiation in the patient.


The first patient with ocular melanoma is treated with protons at Mass General Hospital.


Advances in imaging technology, including CT, MRI and PET scans, help researchers to better diagnose and see tumors, making proton therapy, which requires identifying the precise location of a tumor, a more practical treatment option.


The FDA approves proton therapy.


The first hospital-based proton treatment center in the United States is built at Loma Linda University Medical Center in Loma Linda, Calif, and the first patient – with ocular melanoma – was treated in October.


As more proton therapy centers treat patients, more research becomes available on the benefits of proton therapy in treating certain cancers.


Even more precise pencil beam scanning first comes online at Massachusetts General Hospital.


Medicare elects to cover proton therapy for many appropriate disease sites.


On March 8, 2013, Seattle Cancer Care Alliance Proton Therapy Center opens in Seattle. It’s the first proton center in the Northwest and the only one within a 1000-mile radius.


The Alliance for Proton Therapy Access forms to advocate for consistent insurance coverage for proton therapy.

As of 2017, there are 25 proton therapy centers in the US, with more under constructions. More proton therapy centers operate and are being built around the world.