PROTON NEWS

CENTER AT CUTTING EDGE OF NUCLEAR MEDICINE

The Indianapolis Star - Indystar.com

By Benjamin Weller
Star correspondent
April 10, 2007


Cancer is a devastating disease. Not only does it destroy bodies and lives, the treatment itself can be damaging. The medical staff at the Midwest Proton Radiotherapy Institute, located at Indiana University's Cyclotron Facility in Bloomington, is working its way around this problem -- literally.

On March 21, a medical team at the institute treated a patient with prostate cancer, using -- for the first time -- a combination of two existing technologies that allow doctors to precisely target a narrow beam of charged particles, or protons, at a tumor from multiple angles.

The technologies, which had not been used in concert before, include a rotating gantry for beam delivery and a robotic patient-positioning system. The gantry allows a proton beam to be rotated 360 degrees around a patient. The robotic arm, of the same type used in car manufacturing, positions the patient, lying on a carbon-fiber bed, in the path of the beam. The combined effect, said Dr. Allan Thornton, medical director at the institute, is a highly accurate form of treatment that "destroys on average one-fifth of normal tissue of even the most elegant of conventional therapies."

Not only is the proton beam more accurate, he said, it also is "cleaner." The team has modified the nozzle through which the beam passes so it produces fewer neutrons, which can cause cancer years later. "If I treat a young child," Thornton said, "one of the issues I have is I'm going to cure that child's tumor, but will I create another tumor twenty or thirty years from now?" The cleaner proton beam, he said, dramatically reduces the chance of that happening. With one fixed-beam treatment room and one rotating-beam room already in operation, and one more rotating-beam room in the works, the institute is looking to greatly increase the number of patients it can treat.

Jim Buher, the company's chief executive and president, said 15 to 16 patients are treated daily. Within a month, he hopes, that number will be up to 35. "When we get all three rooms up and running, we should be able to treat at full capacity about 75 to 80 patients a day," he said. Proton therapy for tumors, both benign and cancerous, has been in use since the 1940s.

While conventional radiation therapy uses a beam of radiation that passes through a tumor and out the other side, a proton beam slows as it passes through electrons in the body. By measuring the body's electron density with a CT scan, an oncologist can stop the proton beam before it passes out of the tumor into healthy tissue.

The availability of such treatment, however, is limited. The insitute's facility is one of only five such clinics in the United States. The sheer size of a facility needed to produce a proton beam is a major limitation. The IU Cyclotron Facility, built in 1975 for research in nuclear physics, sits on about 3 acres of land. Rotating the proton beam also demands space. The rotating gantry is 38 feet in diameter, so each treatment room is about 40 feet wide. The machine itself weighs 90 tons.

Proton therapy is more common in Europe and Japan, where single-payer health-care systems allow for a more even disbursement of resources, according to Thornton, who blamed the scarcity of such resources in this country on the "competitive posturing of health-care delivery."

With a particle accelerator already in place, and with the help of engineers from IU, the cost of building the treatment facility was greatly reduced. Buher estimated that once the third treatment room is completed, the total cost of the facility will be $50 million to $60 million. Other such U.S. treatment centers have exceeded $100 million. The reduction in cost may not mean cheaper treatment fees, which the institute negotiates with each patient. However, it does mean more patients can receive proton therapy. "I can't claim that they'll see the savings," Thornton said, "but they're going to see it in accessibility, because frankly it wouldn't be here if we couldn't do it for this (amount of money). "We've used an existing facility and done all this ourselves."

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