A new camera system developed by researchers at the University of Illinois Urbana-Champaign and Carle Illinois College of Medicine (CI MED) could help surgeons instantly determine whether to remove a patient’s lymph nodes during cancer surgery. The system uses ultraviolet and near-infrared light to give surgeons a ‘smart vision’ view that can inform clinical decisions, streamline surgical workflows, and improve patient care.
“This technology addresses an important unsolved problem in surgery: determining during the operation whether a lymph node is metastatic (the site of cancerous spread),” CI MED Professor and Principal Investigator Viktor Gruev said.
In treating patients with breast cancer and lung cancer, surgeons face difficult decisions on how much tissue to remove, because these cancers often spread beyond the known tumor site to nearby lymph nodes. The current protocol for determining if lymph nodes are cancerous is microscopic inspection of tissue biopsied during surgery. To minimize the risk of cancer spread or additional surgeries, some clinicians may decide to remove more lymph nodes than necessary, which can result in an extended recovery for the patient.
“Our system combines ultraviolet, visible, and near-infrared imaging on a single chip, allowing surgeons to localize lymph nodes and assess whether they are likely metastatic,” said Zhongmin Zhu, a doctoral student in electrical and computer engineering at Illinois who served as lead author on the project.
The research team’s triple-signal approach is inspired by the remarkably wide-spectrum vision of the mantis shrimp, which can detect light invisible to the human eye. The team used near-infrared (NIR) light to illuminate even hard-to-find lymph nodes using a medical dye called indocyanine green (ICG). Imaging with deep ultraviolet (UV) light reveals the presence (or absence) of high levels of tryptophan, a naturally occurring chemical marker found in malignant lymph nodes. The new camera system captures regular color images, UV, and NIR signals in a single view.
When fully developed for surgical use, Gruev says the images could inform clinical decisions in real time. “If a lymph node is healthy, future versions of this approach could help surgeons leave it in place, which may reduce unnecessary node removal and lower the risk of complications such as lymphedema (tissue swelling) and reduced mobility. If a lymph node is positive (for cancer), the surgeon could potentially adjust the operation immediately, which may help avoid secondary surgeries,” he said.
Through a multi-disciplinary partnership involving three universities and a hospital in North Macedonia in Europe, the imaging system was developed and tested in both lab experiments and using surgical specimens from breast cancer patients immediately following mastectomy surgery. Results showed that the camera efficiently identified cancerous lymph nodes (97% sensitivity) and avoided false alarms most of the time (89% specificity). The system hasn’t been tested in a living organism (in vivo testing).
“Even in its current ex vivo form (tested in tissues outside a living organism), the technology shows strong promise for improving surgical decision-making and patient care,” Gruev said. “Our goal is to make the system faster, more sensitive, and easier to integrate into the operating room.”
Gruev is expanding on his longstanding partnerships with experts in engineering, biology, and pathology at the University of Pennsylvania, Dartmouth College, the University of Maryland, and Ss. Cyril and Methodius University of Skopje, North Macedonia, to include a new clinical partnership with Dr. Claudius Conrad, CI MED's Associate Dean for Research and Innovation, and Carle Health, providing surgical oncology expertise in adapting the system for clinical use.
“Our next step is to improve the sensitivity of the ultraviolet channel so the technology can move closer to in vivo use during surgery. We are also expanding the clinical studies, improving the sensor and image reconstruction, and further correlating the optical signals with pathology,” Gruev said.
Gruev’s lab originally developed bio-inspired camera technology while working on another research project. After a period of dormancy, the team adapted their previous work to provide surgeons with timely, unprecedented insight into lymph node involvement in cancer patients.
“One of the most exciting aspects of this work is that it shows how curiosity-driven, bioinspired engineering can lead to unexpected advances in medicine. This is exactly the kind of interdisciplinary path that can lead to major breakthroughs,” Gruev said.
The team’s work is summarized in their research paper Bioinspired Ultraviolet-to-Near-Infrared Imager for Label-Free Intraoperative Assessment of Lymph Node Metastasis, recently published in the journal Optica, a leading journal in the field of optics and photonics. In addition to Zhu, PhD candidate Yifei Jin was a lead author on the project.
Editor’s note: Viktor Gruev is a professor in the Departments of Biomedical and Translational Sciences at CI MED, Electrical and Computer Engineering, and Bioengineering at The Grainger College of Engineering and is affiliated with the Cancer Center at Illinois and the Beckman Institute for Advanced Science and Technology at the University of Illinois Urbana-Champaign.
The team’s research was supported by the U.S. Air Force Office of Scientific Research, the Office of Naval Research, the National Science Foundation, and the National Institutes of Health, including an NIH program that supports Professor Gruev’s broader collaboration with the University of Pennsylvania.
This work was featured on WCIA-TV News. You can view the story here.