Proton accelerator

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Contents 1 Proton Accelerator 2 What is a Proton Accelerator and how does it work? 3 When was this Invented? 4 When is it used?

[edit] Proton Accelerator

[edit] What is a Proton Accelerator and how does it work?

A Proton Accelerator is a very large device that uses magnets to accelerate protons and charge them with a specific amount of energy. These protons are then sent through a series of channels to a patient who is on a gantry. The protons travel into the body at which point about 80% of the protons travel to a set depth within the body, the rest stop at locations either more shallow or deep than the intended target tissue. The depth of the proton penetration is set by the amount of energy that is delivered to the proton in the accelerator itself, the more energy the deeper the penetration. This is notably useful because the proton once in the body has the ability and tendency to destroy or change the composition of a target tissues cell DNA. This is effective in treating cancer because the malformed cancer cells will no longer be able to replicate. The advantage of this type of cell destruction is that it is very direct and has a very minimal effect on surrounding tissues. This is opposed to x-ray radiation that causes damage to epidermal and muscle tissue at because up to 50% of x-rays energy is absorbed at the very first collision with the body. Proton accelerator's allow protons to be delivered at a set depth and therby causes little to no damage to any other tissues. This improves efficacy and allows more safe radiation doseage to be given because more of the radiation arrives at the intended destination.

[edit] When was this Invented?

n 1946, proton beam medical treatment was proposed by Robert Rathbun Wilson, PhD. The late Dr. Wilson, who was later to become the first director and largely the creator of Fermi National Accelerator Laboratory (Fermilab), had unusual breadth and depth of vision. His insights about the medical use of protons were partly a legacy of his physics education at the University of California, Berkeley, under Ernest O. Lawrence. However, Wilson's proposal was original in that it specified the mechanisms by which proton radiation treatment would work; his observations are as valid now as they were then, and laid the foundation for proton radiation treatment as it is delivered today at Loma Linda and elsewhere. Dr. Wilson advocated a proton facility at Fermilab shortly after the National Laboratory opened, and supported a neutron facility at Fermilab when local physicians preferred that modality. He always believed in proton radiation treatment, however, and later became a strong supporter of the Loma Linda proton facility.

Eight years later, at the University of California, Berkeley, the first patient was treated with protons. The Berkeley investigators, notably Cornelius A. Tobias, PhD, were instrumental in helping to spread the practice of proton and heavy-charged-particle treatment in research laboratories. Dr. Tobias advised and taught investigators at the University of Uppsala, in Sweden, and at Harvard Cyclotron Laboratory, USA. Uppsala (1957) and Harvard (1961) were the next laboratories to offer proton-beam radiation for treating human diseases. During the 1960s, 1970s, and 1980s, other physics facilities around the world offered proton and other heavy-charged particle treatments.(http://llu.edu/proton/history/)

The first Facility to offer public treatments using proton therapy was the Loma Linda University Adventist Health Sciences Center, specifically the Loma Linda University Medical Center. At this location the first clinical implementation of proton therapy was tested and used.

[edit] When is it used?

It is used primarily in treatment of cancer, and is specifically effective in the treatment of prostate cancer in men. The effectiveness of proton therapy is many times that of traditional radiation treatments.

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