Accelerator physicists strive to lower cost of cancer treatment

May 28, 2010 | 6:56 am

Several facilities that will offer cancer patients the latest innovation in hadron therapy, a medical application of particle accelerators, are under construction in Europe and Asia.

But so far the high cost of building and operating these facilities has prevented the treatment from becoming widely available.

Accelerator physicists from industry and academia challenged one another this week at the International Particle Accelerators Conference in Kyoto, Japan, to find ways to make the treatment, carbon-ion therapy, more affordable.

Hadron therapy uses an accelerator to send particles such as protons or ions into a patient’s tumor. The particles travel through the patient’s body and release most of their energy into the tumor cells, damaging them while limiting harm to the surrounding healthy tissue.

The development of proton therapy was a huge advancement in the treatment of cancer and is often just as effective as the more expensive carbon-ion therapy, said William Chu of Lawrence Berkeley National Laboratory in a talk on the subject of carbon-ion therapy this week at IPAC ’10. It has been the most widely used form of the treatment.

By the end of 2009, about 78,000 patients worldwide had been treated using hadron therapy, according to the Particle Therapy Co-Operative Group, PTCOG. About 86 percent were treated with protons, and less than 10 percent–about 7000 patients–with carbon ions.

Both treatments damage the DNA in a tumor cell, which can lead to its death, said Chu, a retired physicist who worked on hadron therapy at Lawrence Berkeley National Laboratory between 1975 and 1993.

DNA is made up of two strands of units called nucleotides that form a double helix. Each nucleotide in a strand has a partner nucleotide in the other strand. Proton therapy usually destroys a nucleotide in a single strand, leaving its partner nucleotide intact. The partner nucleotide can tell an enzyme how to replace the nucleotide that was destroyed. This way, the body can repair the damaged cancer cell.

Carbon ions, on the other hand, are more likely to damage both strands of DNA. This leaves enzymes without instructions on how to repair the cell and makes it more likely to die.

Using carbon ions also can be more effective in tumors with large centers void of the dissolved oxygen that blood vessels deliver, Chu said.

Four facilities currently offer carbon-ion therapy: the Heavy-Ion Medical Accelerator in Chiba, Japan; the Hyogo Ion Beam Medical Center in Hyogo, Japan; GSI in Darmstadt, Germany; and the Heidelberg Ion Beam Therapy Center in Heidelberg, Germany. Six new carbon-therapy facilities are under construction in Wiener Neustadt, Austria; Pavia, Italy; Heidelberg, Marburg, and Kiel, Germany; and Maebashi, Japan.

However, Chu said, building and operating a facility for carbon-ion therapy costs about twice as much as building and operating one for proton therapy–already an expensive venture at $120 to $180 million. So accelerator physicists will need to develop cheaper ways to offer the treatment if it is to gain the prominence of its more popular relative.

Kathryn Grim

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Middle East accelerator project approaches barrier

May 27, 2010 | 10:56 am

Members of an unlikely international collaboration constructing the Middle East’s first synchrotron light source have dealt with outdated equipment, inexperience, and language barriers.

But one hurdle looms particularly large in their path: They need to gather more than $24 million to complete the final section of the accelerator.

The collaboration has struggled to find the funds within its membership and has begun discussions in Europe and the United States, said technical director Amor Nadji in a talk at IPAC ‘10.

A synchrotron accelerator uses magnets to circulate electrons at almost the speed of light, creating a beam of bright ultraviolet and X-ray light. Scientists use beams from synchrotrons in materials science and biomedical applications. For example, biologists used a synchrotron light source to establish the double-helical structure of DNA.

The Synchrotron Light for Experimental Science and Applications in the Middle East, or SESAME, represents a rare example of cooperation between Bahrain, Cyprus, Egypt, Iran, Israel, Jordan, Pakistan, Palestinian Authority, and Turkey.

Young scientists from around the contentious region have been working side-by-side on construction of SESAME since 2003.

“The purpose is to try to use science for peace,” Nadji said.

Physicists Herman Winick, Gustav-Adolf “Gus” Voss, and others planted the seed for the project in 1997 when they proposed that Germany donate rather than scrap a recently decommissioned synchrotron called BESSY I.

As scientists in Germany began construction of the synchrotron’s successor, BESSY II, others packed the components of the original into crates and shipped them to a town near Amman, Jordan.

The process of fitting the pieces back together into a working accelerator has not been easy. Scientists have had to find replacements for parts built in the ‘70s and decipher notes handwritten in German. On top of that, most of those willing to work on SESAME are fresh out of school.

“Building an accelerator is not something you can learn in class,” Nadji said. “You need to go to the laboratory.”

More experienced scientists tend to go abroad to participate in projects with more stable funding, which offer higher salaries. Nadji grew up in Algeria but moved to France to complete his PhD. He worked at the Laboratoire pour l’Utilisation du Rayonnement Electromagnetique, or LURE, and more recently helped build the Soleil synchrotron near Paris.

Nadji said he enjoys the teaching aspect of his job at SESAME.

“These are inexperienced people,” he said. “But if they have confidence in you, it’s a very good atmosphere. Every day at the end of the day, I think I did something good because I told this one about a strategy he didn’t know or because I know that one can manage something on his own now.”

Despite their freshness, members of the SESAME collaboration are not content simply to rebuild the German synchrotron. They plan to upgrade the accelerator to run at 2.5 gigaelectronvolts, up from its original 0.8 GeV.

The improvement necessitates a storage ring about twice the size of the original and raises the cost of building the accelerator from its original estimate. But it will make SESAME competitive with other synchrotrons around the world, an important factor in attracting veteran scientists to use the machine.

Read more about the origins of SESAME in symmetry.

Kathryn Grim

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Physicists hold first international particle accelerator conference

May 24, 2010 | 10:27 am

For decades, scientists from laboratories and universities around the world have worked together to build and operate particle detectors.

Until recently, accelerator physicists have done just the opposite, working predominantly with fellow scientists at the same institution to build their machines.

This week hundreds of accelerator physicists have gathered in Kyoto, Japan, to take part in the first International Particle Accelerator Conference, taking a step toward the practices of their detector-building colleagues. “Any new accelerator will surely need to be built in an international collaboration,” said Katsunobu Oide, chair of the IPAC 2010 organizing committee, in his introductory remarks.

Detector builders expect to work with collaborators from outside their institutions. If a particle physicist wants to take part in an experiment, he or she must take some responsibility for the detector by helping with construction or taking shifts running it.

There is no similar expectation that the scientist help build or run the accelerator that delivers particles to the detector. The physicists, engineers, and technicians that do this historically have had little assistance from outside the host institution.

One reason for this is that operating an accelerator is more complicated than operating a detector, Oide said.

“A detector is more of a passive device,” he said. “Once you build it, you use it.” The major work takes place during construction.

But an accelerator requires constant, specialized attention. “It cannot be automatic if you want cutting-edge performance,” he said.

Those who run particle accelerators need to work in close proximity to the accelerator so that they can investigate if something goes wrong. The philosophy has been that if locals are going to operate the accelerator, they might as well build it, too.

But particle accelerators have grown larger and more complex over time. It is no longer feasible for a single institution to provide the manpower and funding necessary to complete construction.

The Hadron Electron Ring Accelerator, or HERA, completed in 1992 at DESY in Hamburg, Germany, was the first accelerator to receive a significant in-kind contribution from a collaborating institution. Italian scientists built half of its 416 superconducting dipole magnets.

Since then, multiple institutions have worked together on accelerators such as the Large Hadron Collider and Europe’s XFEL. Proposed future accelerators such as the International Linear Collider, the Compact Linear Collider, and the muon factory are set to follow this trend.

This week, accelerator scientists at IPAC 2010 hope to find new ways to capitalize on the advantages and manage the disadvantages that the new experience of working as a team can bring.

Kathryn Grim

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