1895
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.
1919
British physicist Ernest Rutherford demonstrates the existence of protons (elementary particles found in atoms).
1931
American physicist Ernest O. Lawrence invents the cyclotron, a machine used in proton therapy, which accelerates charged particles to high energy levels.
1937
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.
1946
American physicist Robert Wilson publishes a study that suggests 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.
1948
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.
1954
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.
1980s
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.
1988
The FDA approves proton therapy as a cancer treatment option.
1990
The first hospital-based proton treatment center in the United States is built at Loma Linda University Medical Center in Loma Linda, Calif.
2001
The first patient is treated at Harvard/Massachusetts General Hospital’s Francis H. Burr Proton Therapy Center in Boston, the second hospital-based proton treatment center in the United States.
2003
The Midwest Proton Radiotherapy Institute (MPRI), the third proton treatment center in the United States, opens in Bloomington, Ind.
2005-2010
Seven more institutions open proton therapy centers in the United States.
2013
On March 8, 2013, SCCA Proton Therapy Center (now Fred Hutchinson Cancer Center - Proton Therapy) opens in Seattle. It’s the first proton center in the Northwest and the only one within a 1000-mile radius.