Reported January 2007

BACKGROUND: An advanced 3-D display system initially developed with automobile design in mind might prove beneficial in the treatment of cancer patients. Rush Medical Center in Chicago, Illinois, is testing the Perspecta Spatial 3D system to improve evaluation and planning of cancer radiation treatments.

HOW IT WORKS: The system consists of a 24-inch dome that plugs into a PC to display holographic (full-color and full-motion) MRI, CT scans and nuclear medicine images in a true 3-D space. Compared to standard 2-D displays, this 3-D image enables physicians to work more precisely and efficiently because they can view and manipulate the images from any vantage point around the 360-degree dome. The effectiveness of radiation therapy depends on the ability to concentrate high doses of radiation on the tumors while minimizing how much the healthy surrounding tissue is exposed, to keep side effects to a minimum. Without the system, oncologists must analyze hundreds of "slices" of 2-D digital images to determine where the radiation is hitting.

ABOUT HOLOGRAMS: A hologram is a 3-D picture, used not only for medical imaging, but also for heads-up displays for airplane pilots to assist in navigation, among other applications. But while a photograph is an actual physical image, a hologram picture merely contains information about the size, shape, brightness and contrast of the object being recorded. This information is based on how light reflects off the imaged object. Shine a light on a hologram and the stored information takes the incoming light and uses it to recreate the original light waves, so your eyes and brain now perceive the object as being in front of you.

WHAT IS IONIZING RADIATION? X-rays and gamma rays are both forms of ionizing radiation. Ions are electrically charged atoms, a byproduct of an X-ray, for example, knocking electrons off of atoms. The resulting free electrons then collide with other atoms to create even more ions. An ion's electrical charge can lead to unnatural chemical reactions inside cells, particularly at the higher energy levels of X-rays. It can break DNA chains, causing the cell to either die or develop a mutation and become cancerous, which can then spread. And if the mutation occurs in a sperm or egg, the result can be birth defects, which is why pregnant women should never be subjected to X-rays. In the early days following their discovery, X-rays were widely considered to be harmless. Radiologists thought nothing of daily exposure to the rays, even though a Scottish researcher who routinely used a fluoroscope to test the quality of X-rays by holding his hand between the tube and the fluorescent screen, developed tumors and eventually lost both his hands. Other reported problems included redness of the skin, numbness, infection and severe pain.

The American Association of Physicists in Medicine contributed to the information contained in the TV portion of this report.

If you would like more information, please contact:

Ben Stein
American Institute of Physics
(for the American Association of Physicists in Medicine)
(301) 209-3088
bstein@aip.org

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