Nine women - six with lymphedema and three controls - were injected with a near-infrared fluorescent dye that has been used safely for 50 years at much higher dosages. The dye is taken up by the lymphatic system. When tissue surfaces are exposed to a dim, near-infrared laser - harmless to the human body - the dye within fluoresces, revealing its transit through the lymphatic system.

"This is the only method that can directly check for improvements in lymphatic function in one sitting, before and after a treatment," says Sevick.

Physicians have several treatment options for controlling lymphedema. They may use compression bandages and massage limbs to manually encourage fluids to drain from the arm. Pneumatic compression devices, sleeves made of segmented chambers that inflate and squeeze, may provide a similar benefit at home, but they may not always be covered by Medicare reimbursements because of lacking direct evidence of their benefit.

"The problem is that there has been no good way to measure direct evidence of benefit," says Sevick. "Hopefully we can use near-infrared fluorescence imaging technique to show improved lymphatic function from these treatments."

The NIR fluorescence technique detected statistically significant improvements in fluid flow through the lymphatic system immediately after the use of pneumatic compression devices. A larger follow-up study will be needed to confirm the results of this pilot study, says Sevick.

Source: Optical Society of America