August 20, 2008 -- On the agenda at this week's 2008 Fall National Meeting of the American Chemical Society is discussion of a new imaging system that highlights cancerous tissue so surgeons can more easily and accurately detect and remove diseased tissue without harming healthy tissue. Massachusetts-based researchers say the fluorescence-assisted resection and exploration (FLARE) system -- which consists of a near-infrared (NIR) imager, a video monitor, and a computer -- is in early clinical trials. The system shows particular promise for improving surgery for breast, prostate, and lung cancer, whose tumor boundaries can be difficult to track at advanced stages; it may also help cancer surgeons avoid cutting critical structures such as blood vessels and nerves.
"The system has no moving parts, uses LEDs instead of lasers for excitation, makes no contact with the patient, and is sterile," says project director John Frangioni, M.D., Ph.D., of Beth Israel Deaconess Medical Center (BIDMC) in Boston and co-director of its Center for Imaging Technology and Molecular Diagnostics. FLARE also gives physicians the power to control multiple viewing angles and different magnification levels through the use of a footswitch.
"This technique is really the first time that cancer surgeons can see structures that are otherwise invisible, providing true image-guided surgery," Frangioni says. "If we're able to see cancer, we have a chance of curing it."
The system uses NIR fluorophores to target specific structures such as cancer cells when injected into patients. When exposed to NIR light, which is invisible to the human eye, the dyes or contrast agents light up the cancer cells and are shown on a video monitor. Images of these "glowing" cancer cells are then superimposed over images of the normal surgical field, allowing surgeons to easily see the cancer cells even in a background crowded by blood and other anatomical structures, the researcher says.
In preliminary studies, Frangioni and colleagues used the FLARE to successfully visualize organs and body fluids of mice and map the lymph nodes of pigs, all in real-time. The first human clinical trials, expected to begin this summer, involve mapping the lymph nodes of a small group of patients with breast cancer. Broader clinical use of the device could occur within five years, the researchers estimate.
In the future, fluorophores could be developed to highlight nerves and blood vessels in one color while visualizing cancer cells in a different color, allowing multiple structures to be viewed easily and even simultaneously, he says.
"The future of the technology now is really in the chemistry," Frangioni says. "We have to develop agents for specific tumors, nerves or blood vessels we're trying to visualize."
The study is funded primarily through a Bioengineering Research Partnership from the National Cancer Institute of the National Institutes of Health.