Sunlight May Help Treat Cancer

BEER-SHEVA, Israel, Dec. 17 -- Dermatologists for years have warned that exposure to too much sun without adequate protection could lead to melanoma, or skin cancer. But one day, "catching some rays" may actually help to treat cancer.
A team of scientists at Ben-Gurion University (BGU) of the Negev have been experimenting with the concept of turning the Earth's largest light source into a cheap and efficient medical laser that could snuff out malignant tumors.
Jeffrey M. Gordon, a professor of BGU's department of energy and environmental physics and the project's lead researcher, says the idea came to him in 1998 when he noticed how "the exorbitant price of surgical lasers" kept them out of reach for many hospitals. The root of the problem, he says, is that most medical lasers require a complex -- and expensive -- means of producing high-intensity light. But much of that light energy isn't needed in certain types of medical procedures.

"We were searching for an alternative to lasers," says Gordon. "Ultrabright, immense power density, light sources uniquely suited to photo-thermal surgery and similar medical procedures."
The answer for Gordon and his team came out of the clear blue sky -- literally.

Bright Spot
"Sunlight can be uniquely suitable for surgical use because it can be concentrated," Gordon wrote in the latest issue of Applied Physics Letters, which details the BGU team's latest experiments. At the heart of their experimental system is a parabolic mirror that measures 20 centimeters (about 8 inches) in diameter. The dish-shaped mirror collects sunlight and concentrates the beams onto a small flat mirror suspended above the center of the dish.
The flat mirror reflects the concentrated light energy into a 1-millimeter-wide fiber optic cable, which can carry the light up to 100 meters away with very little loss of energy. At the other end of the fiber optic cable, the light can be directed onto any target -- against a cancerous section of a patient's kidney, for example.

Zapping Chicken Parts Cheaply
According to Gordon, the initial performance of the setup has been "excellent." As reported in Applied Physics Letters, the solar-powered laser has been able to deliver about 5 to 8 watts of energy, similar to what some conventional medical lasers can deliver.
And in initial tests against animal tissue -- fresh chicken breasts and livers -- Gordon says the setup appears to function much like a medical laser.

"We have 'killed' up to several cubic centimeters of chicken liver in a few minutes with only a few watts of radiative power," he says. What's more, Gordon says such a setup uses existing and relatively inexpensive technology.
"Based on conversations I've had with manufacturers, I would project that if the solar surgery prototype could be mass produced, it has the potential to cost around $1,000 per unit," he says. By comparison, he says traditional medical lasers can cost up to $150,000.

"There are many places in the world -- South East Asia, China, India, South America -- that cannot afford [traditional] laser fiber optics," says Gordon. "We've been overwhelmed by the number of interested parties."
Gordon and his team are plugging away with their research. They are working with physicians from the BGU's Soroka Medical Center to develop the protocols needed to test the device on live lab animals. Gordon hopes to soon try experiments involving organs with malignant tumors in rats. And while that might take a few years to develop, Gordon notes that the device has already spawned other nonmedical experiments.

For more information, visit: www.bgu.ac.il