Study: Near-infrared fluorescence imaging can evaluate lymphatic response
Near-infrared (NIR) fluorescence imaging may be useful to evaluate lymphatic response to pneumatic compression devices therapy in breast cancer survivors, according to a study published in the inaugural issue of Biomedical Optics Express.

Lymphedema affects up to 50 percent of all breast cancer survivors. In lymphedema, fluids accumulate in the arms, potentially causing disfiguring and debilitating swelling that can impact quality of life.

The pilot study employed an investigational, NIR fluorescence imaging technique to evaluate lymphatic response to pneumatic compression devices therapy in normal control and breast cancer-related lymphedema (BCRL) subjects.

The research was conducted by Eva Sevick, PhD, director of the center for molecular imaging at the University of Texas Health Science Center in Houston (UTHSC) in collaboration with Caroline Fife, MD, director of the Memorial Herman Wound Care Clinic at UTHSC, and colleagues.

The UTHSC research team's near-infrared fluorescence imaging technique examined the root cause of lymphedema: blockages or damages in the lymphatic system that prevent fluid from circulating through the body and cause it to pool in the limbs.

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 was taken up by the lymphatic system. When tissue surfaces were exposed to a dim, near-infrared laser – harmless to the human body – the dye within fluorescesed, 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," said 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 a lack of direct evidence of their benefit.

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

Lymphatic propulsion rate, apparent lymph velocity, and lymphatic vessel recruitment were measured by the researchers before, during, and after advanced pneumatic compression device therapy.

Lymphatic function improved in all control subjects and all asymptomatic arms of BCRL subjects. Lymphatic function improved in four of six BCRL affected arms, with improvement defined as proximal movement of dye after therapy. A larger follow-up study will be needed to confirm the results of this pilot study, said Sevick.

The research was funded by the National Institutes of Health and by Tactile Systems Technology which manufactures and markets the Flexitouch pneumatic compression devices tested in this research.