News Release

SCIENCE HIGHLIGHTS of the 50th AAPM Meeting in Houston, July 27 to July 31

1. GOLD NANOSHELLS HELP VISIBLY HEAT AND DESTROY CANCER

Most cancer tumors that have clear borders and are well defined have traditionally been treated successfully by surgical removal. But not all cancers respond to conventional surgery. More importantly, conventional surgery brings risks of complications and long recovery periods that can negatively impact a person’s quality of life.

To overcome these treatment limits, a group of researchers based at the University of Texas' M.D. Anderson Cancer Center, turned to lasers and nanotechnology. They explored an emerging minimally-invasive approach to treating tumors that delivers a lethal dose of laser-generated heat to tumors, known as thermal ablation. To improve thermal ablation, they added a nano-twist that precisely guides and concentrates heat in targeted tumors.

Working with Nanospectra Biosciences, Inc., researchers injected nanoshells made of gold silica into canine models of brain cancer. The nanoshells homed to the target tumors, where they were taken in by the tumor cells. Next, researchers irradiated the nanoparticle-filled tumor with low-power laser light to selectively heat the tumor-but not the surrounding, healthy tissue. M.D. Anderson researchers added iron-oxide cores to the nanoshells to make them visible by magnetic resonance imaging so researchers could observe the process.

Results from these experiments were supported by numerical modeling studies, and by scanning electron microscope data showing destructive thermal increases near the tumors’ blood supplies. "Based on these encouraging early results, we conclude that the use of magnetic resonance temperature imaging and gold nanoshells hold the very real possibility of meeting the long-sought goal of improving the precision of thermal ablation, while sparing healthy tissue," explains M.D. Anderson Cancer Center’s R.J. Stafford, Ph.D. (jstafford@mdanderson.org). “Temperature imaging and guidance is an invaluable tool furthering this approach as it moves from feasibility studies to future use in human clinical trials."

Talk (WE-C-351-1), "Characterization of Gold Nanoshells for Thermal Therapy Using MRI" is at 10:00 a.m. on Wednesday, July 30, 2008 in room 351. Abstract: http://www.aapm.org/meetings/amos2/pdf/35-9309-76032-210.pdf.

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HOW TO COVER THE MEETING

Reporters who would like to attend the meeting in person should fill out the press registration form on the AAPM Virtual Press Room. See: http://www.aapm.org/meetings/08AM/VirtualPressRoom/documents/pressregform.pdf.

Reporters who would like to cover the conference remotely will find releases and articles on the Virtual Press Room highlighting many of the interesting and important talks presented at the meeting. Even if you can't make it to Houston, the Virtual Press Room will make it possible to write stories about the meeting from your desk.

ABOUT AAPM

The American Association of Physicists in Medicine (AAPM) is a scientific, educational, and professional nonprofit organization whose mission is to advance the application of physics to the diagnosis and treatment of human disease. The association encourages innovative research and development, helps disseminate scientific and technical information, fosters the education and professional development of medical physicists, and promotes the highest quality medical services for patients. In 2008, AAPM will celebrate its 50th year of serving patients, physicians, and physicists. Please visit the association's Web site at http://www.aapm.org/.

ABOUT AIP

Headquartered in College Park, MD., the American Institute of Physics is a not-for-profit membership corporation chartered in New York State in 1931 for the purpose of promoting the advancement and diffusion of the knowledge of physics and its application to human welfare.

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Media contacts:

Jason Socrates Bardi, American Institute of Physics,
301-209-3091 (office) 858-775-4080 (cell)
jbardi@aip.org

Jeff Limmer, AAPM Media Relations Subcommittee Chair
jeffl@aspirus.org