Cutting Cancer by Color

The key to a successful cancer surgery is the removal of all of the diseased tissue, but sometimes tumor boundaries can be difficult to track. However, researchers in Massachusetts have developed a new imaging system that highlights cancerous tissue in the body, making it easier for surgeons to see and remove the diseased tissue.

Early clinical trials have shown promise for improving surgery for breast, prostate and lung cancer, while helping surgeons avoid cutting critical structures such as blood vessels, nerves and normal tissue near the tumor.

A futuristic imaging technique could improve cancer surgery by revealing hidden anatomical details. Photo of a pig's hind leg viewed after injection with near-infrared contrast agents and imaging with near-infrared light to highlight lymph flow. Photos courtesy of John V. Frangioni, BIDMC.

"This technique is really the first time that cancer surgeons can see structures that are otherwise invisible, providing true image-guided surgery," says project director John V. Frangioni of Beth Israel Deaconess Medical Center (BIDMC) in Boston and co-director of its Center for Imaging Technology and Molecular Diagnostics. "If we're able to see cancer, we have a chance of curing it."

The portable Fluorescence-Assisted Resection and Exploration (FLARE) has been under development for the past decade and consists of near-infrared (NIR) imaging system, a video monitor and a computer.

"The system has no moving parts, uses LEDs instead of lasers for excitation, makes no contact with the patient, and is sterile," Frangioni says.

The unique system uses special chemical dyes called NIR fluorophores that are designed to target specific structures such as cancer cells when the dyes are 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.

The Fluorescence-Assisted Resection and Exploration (FLARE) device.

Frangioni compares the system to the old color-by-number paint sets. Instead of coloring by numbers, it will provide surgeons with a means of "cutting by color," he says. The computerized technique also gives physicians the power to control multiple viewing angles and different magnification levels through the use of a footswitch.

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.

For more information, visit: www.bidmc.harvard.edu