<p>Power to Protons</p>
<p>October / November 07 By: Annie Jia Volume 5 Number 5
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<p>Protons from cyclotrons were first used to treat cancer in 1954. That was the year that John Lawrence, brother of physics icon E. O. Lawrence (after whom the Lawrence Berkeley and Lawrence Livermore laboratories were named), first demonstrated the dramatically improved method of radiation therapy that precisely targets cancer cells while sparing healthy cells. The technology, the cyclotron, had been invented two decades ago for physicists to study atomic nuclei.</p>
<p>More than half a century later, medical cyclotrons for radiation treatment are a mainstay at five major hospitals in the United States. Though the industry is still nascent, experts today believe that the audience is finally ready and the market ripe for proton therapy—€”the main medical cyclotron radiation therapy—€”to take off.</p>
<p>“In the past five years, the interest from the medical community has grown almost super-exponentially,” says Dr. Thomas Bortfeld, director of physics research in radiation oncology at the Massachusetts General Hospital in Boston. “I believe proton therapy will become a dominant treatment modality in the future.”</p>
<p>Knowledge and capital have coalesced in recent years, and key players have begun to recognize and exploit the emerging opportunities. What people commonly think of as cancer radiation treatment uses X-rays, or high-energy light beams, to kill tumors. But X-ray beams damage much healthy tissue along with the cancerous cells, often resulting in severe side effects and illness following radiation therapy.</p>
<p>Proton therapy, on the other hand, shoots beams of protons—€”or hydrogen nuclei—€”at tumors. The advantage of protons can be traced back to a basic physical property that causes them to discharge most of their energy in one burst at one location. Since the energy release is what kills tissue, protons are perfectly suited for destroying a dense lump—€”such as a cancerous tumor.</p>
<p>“You’re better able with protons to spare normal tissues,” says Richard Maughan, vice chair and director of physics of the Department of Radiation Oncology at the University of Pennsylvania. “So you get less complications, and you can escalate the dose to the tumor.”</p>
<p>The benefit is most dramatic in cancers that sit near vital organs, for which proton therapy would avoid critical brain or lung tissue damage, for example. Also prime are pediatric cases, where irradiating healthy tissue poses a significant risk of inducing new cancers later in life.</p>
<p>“As soon as there are more of these machines, it would be almost unthinkable to take a child who has cancer to get X-ray therapy,” says Dr. Herman Suit, chief of the Department of Radiation Oncology at Mass General.</p>
<p>Years of studies at the few leading hospitals were needed before doctors were convinced of proton therapy’s value, says Didier Cloquet, vice president of corporate communication at IBA, a Belgian company that is the world’s leading supplier of medical cyclotrons. “This time is now over.”</p>
<p>Today, about 35 proton therapy medical cyclotrons exist worldwide, compared to thousands of X-ray centers. Proton therapy accounts for less than half of one percent of all cancer radiation treatments, Bortfeld estimates.</p>
<p>But medical and industry experts alike express high hopes for growth of the field, and IBA is in the process of installing twelve new centers, according to Cloquet.</p>
<p>“Some oncologists think there should be at least 150 proton machines in the United States. Some oncocoloists think it’s possible protons will replace X-rays,” says Timothy Antaya, principal researcher at MIT’s Plasma Science and Fusion Center and a developer of advanced medical accelerator technology.</p>
<p>Current costs of installing a full proton therapy system with one cyclotron supplying four treatment rooms, would average around $100 million—€”four to five times higher than an X-ray center with comparable treatment capacity using four machines. Manufacturers believe that costs will naturally go down for proton therapy—€”as for most new technologies—€”over time, following economies of scale and improved production techniques. But size, too, remains a barrier for adoption. A typical proton therapy cyclotron spans about two to three meters across. Because of limited hospital space and explorations of using mounted cyclotrons, a smaller machine would be a “huge advantage,” Bortfeld says.</p>
<p>In light of these concerns, a felicitous development has been the superconducting medical cyclotron, which was developed for proton therapy at the National Superconducting Cyclotron Laboratory (NSCL) under founding director Henry Blosser in 1993.</p>
<p>Compared to room temperature cyclotrons, which are the standard model today, superconducting cyclotrons—€”packing more of an electromagnetic punch into a smaller size—€”use significantly less material, thus weighing one-fifteenth to one-twentieth less and costing half as much, Blosser estimates.</p>
<p>In 2000 a small German company, ACCEL, procured the technology from NSCL, and earlier this year, Varian Medical Systems, the largest producer of radiation therapy technology in the world, acquired ACCEL.</p>
<p>“We’ve been very pleased with the reaction of the market to this company,” says Andy Thorson, vice president of business development at the Palo Alto-based Varian. “We have had significantly more interest than we originally expected.”
Two superconducting cyclotrons for proton therapy are currently in place, and Varian hopes to install upwards of two dozen in the next five to six years.</p>
<p>New companies are also entering the scene. Still River Systems, a Boston-based company co-founded by Antaya (who studied under Blosser as an NSCL graduate student), is pioneering superconducting synchrocyclotrons. The new machines may be a tenth the cost and an eighth the weight of today’s room temperature medical cyclotrons.</p>
<p>Doctors in Germany and Japan are also honing in on treatment using heavy ions, which grew from work in the 1970s at Lawrence Berkeley National Laboratory. The technology, which is similar to proton therapy, has the potential to be even more precise. However, most experts agree it is too early to tell if one will be the winner.</p>
<p>A large factor that will influence how widely and quickly proton therapy is adopted is the availability of financial support from social institutions, such as governments or insurance companies.</p>
<p>In many countries, such as France and Germany, it is common for the government to pay for most of a patient’s proton therapy treatment, varying by country but averaging 80 percent, Cloquet says. In the United States, Medicaid pays for the treatment and most insurance companies will cover it on a case by case basis.
Furthermore, investing in proton therapy saves society money in the long run as more effective cancer treatments prevent relapses and reduce the risk of inducing new cancer, experts say.</p>
<p>Many doctors say that even if the overall cost of proton treatment remains higher, the benefit of unmistakably better treatment is impossible to ignore. Meanwhile, scientists point to the technology as just one example of the value of basic research.</p>
<p>“In a sense physics has driven medicine,” says Jeff Stetson, an NSCL beam physicist. “Industry is not interested in developing things and then waiting ten years for the profits. That’s the proper place of government-sponsored research.”</p>
<p>Annie Jia is a science writer at the National Superconducting Cyclotron Laboratory.</p>
<p>source: [Power</a> to Protons | Innovation America](<a href=“http://www.innovation-america.org/power-protons]Power”>http://www.innovation-america.org/power-protons)</p>
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<p>The K250 Proton-therapy Cyclotron
Home › The K250 Proton-therapy Cyclotron</p>
<p>Design detail of the K250 that forms the basis for ACCEL corporation’s proton-therapy cyclotron. more</p>
<p>NSCL developed a conceptual design for a superconducting K250 cyclotron for proton-therapy of cancer patients. This conceptual design forms the basis for the new 250 MeV proton accelerator built by ACCEL corporation to become part of a proton therapy facility at the Paul Scherrer Institute, Villigen, Switzerland. Our laboratory collaborates with ACCEL and provides technology transfer and expert advice.</p>
<p>A beam of protons has many advantages for radiation treatment of cancer. Since protons have an electrical charge, they can be focused to a “pencil-thin” beam if desired. They also have the property that most of the beam will stop at the same depth in the patient’s body. This depth can be calculated, and the beam energy can be chosen to make most of the beam stop at the cancer, destroying the cancer in the process with minimal damage to surrounding tissue. For this reason, proton therapy is the treatment of choice for inoperable tumors, such as tumors located in the eye, close to main arteries, or in regions of the brain that are difficult to access by surgery.</p>
<p>The superconducting proton cyclotron has many design features in common with NSCL cyclotrons. In the model drawn you can see a section of the cylindrical yoke of the main magnet drawn in green in the diagram, with the north and south magnetic poles colored yellow. The superconducting coils are wound around the magnetic pole tips, and the coils are immersed in liquid helium (the cylinder that has been cut away in the drawing to show the coils inside) to keep them at the superconducting temperature of about -450 °F or 4 Kelvin. The four spiral-shaped high-voltage electrodes that accelerate the protons are shown in pink, and the high-voltage signals go in through the tuning elements on the top of the cyclotron (there are symmetric tuning elements on the bottom of the cyclotron that do not show in the drawing). In the picture, the cyclotron is open; in the operating position, the top cap is lowered to mate with the yoke.</p>
<p>source: [The</a> K250 Proton-therapy Cyclotron | National Superconducting Cyclotron Laboratory (NSCL)](<a href=“http://www.nscl.msu.edu/tech/accelerators/k250]The”>http://www.nscl.msu.edu/tech/accelerators/k250)</p>
<p>Computer-generated illustration of the superconducting K250 cyclotron designed at NSCL. This 250 MeV (million electron volts) proton accelerator is being built by the ACCEL corporation and will be used in cancer treatment.</p>
<p><a href=“http://www.nscl.msu.edu/media/image/experimental-equipment-technology/k250[/url]”>http://www.nscl.msu.edu/media/image/experimental-equipment-technology/k250</a></p>
<p>Go State!!! lol</p>