Cancer surgeons use new imaging system to ?cut by color?
A new imaging system that highlights cancerous tissue in the body offers surgeons the ability to remove diseased tissue with less damage to normal tissue near the tumor.

The technique, called FLARE, or Fluorescence-Assisted Resection and Exploration, shows promise for improving surgery for breast, prostate, and lung cancer, whose tumor boundaries can be difficult to track at advanced stages, according to researchers who presented their research at the 236th National Meeting of the American Chemical Society (ACS). It could also help cancer surgeons avoid cutting critical structures such as blood vessels and nerves, the researchers said.

"This technique is really the first time that cancer surgeons can see structures that are otherwise invisible, providing true image-guided surgery," said project director John Frangioni, MD, PhD, of Beth Israel Deaconess Medical Center 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."

Under development for the past decade, the portable system consists of a 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 said.

Using special chemical dyes, called NIR fluorophores, the system targets 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 the video monitor. Images of these "glowing" cancer cells are then superimposed on 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, according to the researchers.

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.” 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 estimated.

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 added.

A Bioengineering Research Partnership from the National Cancer Institute primarily provided funding for the study.