Wearable glasses help surgeons view cancer cells in real time
February 17, 2014
Washington University School of Medicine scientists have developed a wearable display to help surgeons visualize cancer cells, which glow blue when viewed through the eyewear.
Cancer cells are notoriously difficult to see, even under high-powered magnification. The glasses are designed to make it easier for surgeons to distinguish cancer cells from healthy cells, helping to ensure that no stray tumor cells are left behind during surgery.
Reducing second surgeries
Current standard of care requires surgeons to remove the tumor and some neighboring tissue that may or may not include cancer cells. The samples are sent to a pathology lab and viewed under a microscope. If cancer cells are found in neighboring tissue, a second surgery often is recommended to remove additional tissue that also is checked for the presence of cancer.
The glasses could reduce the need for additional surgical procedures and subsequent stress on patients, as well as time and expense.
According to breast surgeon Julie Margenthaler, MD, an associate professor of surgery at Washington University, who performed the operation, about 20 to 25 percent of breast cancer patients who have lumps removed require a second surgery because current technology doesn’t adequately show the extent of the disease during the first operation.
“Our hope is that this new technology will reduce or ideally eliminate the need for a second surgery,” she said.
Glowing cancer cells
The technology, developed by a team led by Samuel Achilefu, PhD, professor of radiology and biomedical engineering at Washington University, incorporates a near-infrared light source, custom video technology, a head-mounted display, CMOS imaging sensor, and a targeted molecular agent (near-infrared quantum dots) that attaches to cancer cells, making them glow when viewed with the glasses.
In a study published in the Journal of Biomedical Optics, researchers noted that tumors as small as 1 mm in diameter could be detected.
Ryan Fields, MD, a Washington University assistant professor of surgery and Siteman surgeon, plans to wear the glasses later this month when he operates to remove a melanoma from a patient. He said he welcomes the new technology, which theoretically could be used to visualize any type of cancer.
“A limitation of surgery is that it’s not always clear to the naked eye the distinction between normal tissue and cancerous tissue,” Fields said. “With the glasses developed by Dr. Achilefu, we can better identify the tissue that must be removed.”
In pilot studies conducted on lab mice, the researchers utilized indocyanine green, a commonly used contrast agent approved by the Food and Drug Administration. When the agent is injected into the tumor, the cancerous cells glow when viewed with the glasses and a special light.
Achilefu, who also is co-leader of the Oncologic Imaging Program at Siteman Cancer Center and professor of biochemistry and molecular biophysics, is seeking FDA approval for a different molecular agent he’s helping to develop for use with the glasses. This agent specifically targets and stays longer in cancer cells.
“This technology has great potential for patients and health-care professionals,” Achilefu said. “Our goal is to make sure no cancer is left behind.” Achilefu has worked with Washington University’s Office of Technology Management and has a patent pending for the technology.
The research is funded by the National Cancer Institute at the National Institutes of Health (NIH).
Abstract of Journal of Biomedical Optics paper
We have developed a near-infrared (NIR) fluorescence goggle system based on the complementary metal–oxide–semiconductor active pixel sensor imaging and see-through display technologies. The fluorescence goggle system is a compact wearable intraoperative fluorescence imaging and display system that can guide surgery in real time. The goggle is capable of detecting fluorescence of indocyanine green solution in the picomolar range. Aided by NIR quantum dots, we successfully used the fluorescence goggle to guide sentinel lymph node mapping in a rat model. We further demonstrated the feasibility of using the fluorescence goggle in guiding surgical resection of breast cancer metastases in the liver in conjunction with NIR fluorescent probes. These results illustrate the diverse potential use of the goggle system in surgical procedures.