Lymph nodes are common pathways for certain cancers to spread, requiring surgical removal. These days lymph nodes are visualized using gamma ray imagers that spot the radioactive Technetium-99m tracer that’s injected near a tumor. This is a slow process that exposes patients to a good deal of radiation, but augmented reality (AR) technology may help overcome this.
Researchers at the Fraunhofer Institute for Computer Graphics Research in Darmstadt, Germany have developed a system that uses indocyanine green (ICG) fluorescent dye as a non-radioactive tracer that is spotted using infrared cameras and augmented reality glasses.
The ICG dye is injected to seep into affected lymph nodes. It is then excited using infrared light, making it glow in the near-infrared spectrum ever so slightly. 3D near-infrared cameras pick up this glow and with the aid of mapping and navigation software, project the location of the glow inside a pair of glasses worn by the surgeon. This projected glow lines up perfectly with the location of the fluorescent dye, giving the surgeon a clear view of what needs to be excised.