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From Medical Miracles to Anti-terrorism, Physics Makes It Happen From improving cancer treatment to helping protect people from bioterrorist attacks, LSU associate professor Erno Sajo is finding new ways to apply physics to everyday life. Sajo, who has been at LSU for more than thirteen years, teaches in the Department of Physics and Astronomy and conducts research in health physics and medical physics, two relatively new areas of physics developed since the discovery of X-rays and nuclear radiation. Sajo said health physics works to protect people, and medical physics looks for new ways to improve medical treatments and assist patients. "This is a different branch of physics," Sajo said. "It's not what people usually think of when they think of physics." Health Physics
Sajo's health physics research is in aerosol transport and dispersion, which can help him find ways to protect humans from inhaled threats, such as radioactive particles, anthrax, or corona viruses like SARS. Sajo studies the dispersion of aerosols in a variety of situations, such as how radioactive particles might disperse through the air if there was a nuclear spill, how airborne anthrax particles might disperse through a room or building, and how chemicals might travel through the air if a chemical plant leaked or was damaged by a hurricane. The Budapest, Hungary, native began his work in these areas hoping to use physics to contribute to the well-being of humans. It wasn't until the September 2001 terrorist attacks on America that Sajo realized his research could have anti-terrorism implications. Physics for Homeland Security  Sajo has developed a computer program that simulates how an aerosol will disperse through a room or building, depending on the size and shape of furniture and other objects in the room and the flow of air currents from air conditioners and ventilation systems. He said the computer simulations could be useful in the area of homeland security. To double-check the accuracy of his computer code, Sajo uses a test chamber that is four feet wide, six feet long and seven feet tall. In that chamber, he releases aerosols and measures their concentrations and size distributions at certain points, then compares his findings to the simulations run by the computer. He learned that, in most situations, his computer code is very accurate. The computer models would be most useful, Sajo said, in recreating a biological attack or accidental release of harmful material to see exactly how the materials dispersed. The models would also be useful in helping engineers and architects design buildings that would minimize the impact of dispersed particles.  After Sept. 11, this research took on a new dimension, as the concept of anthrax spreading through the U.S. Capitol became a reality. Sajo began working with LSU's anthrax researcher, Martin Hugh-Jones of the LSU School of Veterinary Medicine, and they have shared some of their findings with the federal government. Sajo said this research can also show how germs can spread through an airplane and whether the germs that are dispersed are concentrated enough to spread illness or disease. These principles could also be applied to outdoor environments, Sajo said, such as the dispersion of particles dropped by a crop duster. Medical Physics Sajo's research in medical physics, or therapy physics, looks for new and better ways to treat patients with certain illnesses, including asthma and cancer. An area in which Sajo is particularly interested is finding ways to improve treatment for prostate cancer patients. For prostate cancer patients who need radiation therapy, one of the current treatments is an application known as brachytherapy, which delivers radiation directly into the tumor through tiny seed-like needles implanted into the prostate. The seeds then deliver on-the-spot, localized doses of radiation. Before surgery, doctors carefully plan where to place the seeds to cover the whole tumor and irradiate a minimal amount of healthy tissue, but the seeds often move around, and don't end up where they need to be. Misplaced or migrated seeds could mean that the prostate is not getting enough radiation, or that healthy tissue is being radiated needlessly. After surgery, doctors take great care to map the location of the seeds with CT scans to compare the actual radiation dose with the planned radiation dose.  The problem, Sajo said, is that finding all the seeds is difficult with current imaging methods. Not being able to locate the seeds means that doctors and physicists cannot calculate the exact dosage of radiation, which hinders the overall treatment process. Sajo said most researchers are looking for better ways to locate the seeds, but because the ultimate goal is to accurately determine the radiation dosages, Sajo has skipped the step of finding the seeds and developed a way to directly measure the radiation delivered. With his technique, each seed would contain a tracer isotope, in addition to the therapeutic isotope, that would allow doctors to measure the radiation dose delivered without ever having to locate the seeds themselves. "I don't need to know where the seeds are, I just want to measure the dose and its distribution," Sajo said. "That's what is important." Sajo said the new technique could significantly improve the accuracy, and therefore, the success, of radiation therapy for prostate cancer patients. The Best of Both Worlds In one of his areas of study, aerosol medicine, Sajo's health physics research intersects with his medical physics research. In his studies of aerosol transport, he examines how inhaled medications, such as those used for treatment of asthma, travel through the respiratory system, how many of the particles end up in the lungs and how deeply the particles go into the lungs. A major application of this research would be improving ways to deliver aerosol medications. Sajo said the research could result in the creation of more effective inhalers, and in the future, could allow doctors to administer other types of drugs, such as insulin, through the respiratory system. LSU's Future Medical Physicists  Sajo, who holds degrees in mechanical and nuclear engineering and a Ph.D. in physics, said the field of medical physics is growing as more and more physicists realize the impact their research can have on everyday life. At LSU, physics majors can take courses in medical physics, some of which are taught by Sajo, and can even earn a concentration in medical physics when they graduate. In addition, the Department of Physics offers a graduate degree in Health Physics and Medical Physics. "Medical physics grew out of nuclear physics and nuclear engineering," he said. "Up until about fifteen to twenty years ago, there was no such degree as medical physics. But people realized there is a tremendous need for scientists who understand the physics of medicine." Contact Kristine Calongne | LSU
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