Researchers from photonics and medicine develop an endoscopic system with Raman spectroscopy for rapid tumor detection in outpatient care.

When cancer is suspected, patients often have to wait days for a diagnosis. The invaScope could speed up this process: the endoscopic system developed at Leibniz IPHT analyzes tissue directly inside the body using light. Initial studies show that the technology could be suitable for routine clinical use. Until now, diagnosing cancer has required a tissue biopsy followed by microscopic analysis—an elaborate and time-consuming procedure. The invaScope offers an optical alternative that could accelerate this process.

The system uses Raman spectroscopy to analyze tissue directly during an endoscopic examination. A fiber-optic probe directs laser light onto the cellular structure. Depending on the molecular composition, the light is scattered differently, creating a spectral “fingerprint” that indicates whether the tissue is healthy or tumor-altered. “With the invaScope, we can identify tumor tissue already during the examination—without a biopsy,” explains Prof. Dr. Iwan Schie, who developed the device with his Multimodal Instrumentation group at Leibniz IPHT. “The system makes Raman spectroscopy usable for contrast-agent-free, in vivo diagnostics.”

The invaScope is designed to integrate seamlessly into clinical workflows and to be easy to operate. The fiber-optic probes can be sterilized multiple times and are compatible with standard endoscopes. Specially developed software controls the measurements and analyzes the spectra in real time.

Clinical tests in Copenhagen

How well this works was investigated in an initial clinical feasibility study at Herlev-Gentofte Hospital in Copenhagen. Twenty-one patients with bladder cancer were examined with the invaScope, while tissue samples were taken in parallel for histopathological analysis—the current gold standard (“In Vivo Proof-of-Principle Study of Raman Spectroscopy in Trial Participants With Bladder Tumours,” NCT05124106, 11/2021). The result: the Raman spectra showed a sensitivity of 83% and a specificity of 75% in distinguishing between tumor and normal tissue. “For the first time, we were able to determine directly during the examination whether a tumor is benign or malignant,” reports Dr. Gregers G. Hermann, principal investigator of the study. “A technology that enables reliable tumor classification already in outpatient care could change the entire diagnostic process.” Practical usability was also tested: the invaScope probes proved reliable, repeatedly sterilizable, and easy to integrate into existing workflows.

New studies in Jena and California

Following the successful first test, the invaScope is undergoing further clinical evaluation. Since 2023, a study has been running at Jena University Hospital focusing on tumors in the head and neck region. Under the leadership of Prof. Dr. Orlando Guntinas-Lichius, Director of the Department of Otorhinolaryngology, up to 100 patients are to be examined, plus 40 individuals with inflammatory diseases as a control group. “The first results are promising,” says Guntinas-Lichius. “But we need to analyze the data in more detail before drawing final conclusions.”

In parallel, another study will start in 2025 at the University of California, Davis (UC Davis). Within the framework of the Jena-Davis Alliance of Excellence in Biophotonics, the invaScope will be combined with a fluorescence lifetime system developed by Prof. Dr. Laura Marcu to investigate whether this technology fusion can further improve tumor margin detection. The study is part of the cooperation between Leibniz IPHT and UC Davis within the National Center for Interventional Biophotonic Technologies (NCIBT), which develops new light-based medical technologies.

Original publication: https://www.mdpi.com/2072-6694/16/18/3238