October 10, 2017
Surgeons at the University of Pennsylvania have achieved a global first with the use of a fluorescent dye that identifies cancerous cells in lymph nodes during head and neck cancer procedures.
The study, led by otorhinolaryngologist Jason G. Newman, seeks to test the effectiveness of intraoperative molecular imaging (IMI), a technique that illuminates tumors to provide real-time surgical guidance.
More than 65,000 Americans will be diagnosed with head and neck cancers in 2017, accounting for approximately 4 percent of all cancers in the United States, according to the National Cancer Institute. About 75 percent of these cancers are caused by tobacco and alcohol use, followed by human papillomavirus (HPV) as a growing source for their development.
Common areas affected by these cancers include the mouth, throat, voice box, sinuses and salivary glands, with typical treatments including a combination of surgery, radiation and chemotherapy.
Lymph nodes, which act as filters for the immune system, are often among the first organs affected by head and neck cancers as they spread or resurface. Initial surgeries may leave microscopic cancerous cells undetected in the lymphoid tissue, heightening the risk that a patient's condition will return after the procedure.
“By using a dye that makes cancerous cells glow, we get real-time information about which lymph nodes are potentially dangerous and which ones we can leave alone,” Newman said. “That not only helps us remove more cancer from our patients during surgery, it also improves our ability to spare healthy tissue.”
With the aid of a fluorescent dye, surgeons are able to key in on suspicious tissue without removing or damaging otherwise healthy areas. Previously adopted for other disease sites in the lungs and brain, the practice now allows Newman's team to experiment with indocyanine green (ICG), an FDA-approved contrast agent that responds to blood flow.
Newman explained that since tumor cells retain the dye longer than most other tissues, administering the dye prior to surgery singles out the areas where cancer cells are present.
The current trial at Penn will enable researchers to determine whether ICG is the most suitable dye for head and neck cancers and provide oncologists with a deeper understanding of how cancer spreads in the lymph nodes.