Imaging System Enables Early Detection of Bowel Cancer

An international research team called PROSCOPE has developed a multimodal optical imaging system capable of detecting bowel cancer at an early stage. The system, which is designed to be fitted to an endoscope, can give clinicians the ability to zoom in on areas of the intestine identified for inspection to create detail-rich 3D images.

The system enables observations with conventional white light in a camera and then switches to more advanced photonic and optical imaging techniques to enable observations at the microscopic and molecular levels; at this point, further analyses of the tissue is possible.

To increase spatial resolution, penetration depth, and molecular sensitivity, the team combined optical coherence tomography (OCT), multiphoton microscopy, and Raman spectroscopy.

Instead of having a traditional camera inserted into the intestine and then surgery to cut away a growth for inspection and analysis, the technique can assist clinicians to avoid unnecessary invasive biopsy by instead peering into the tissue in greater detail. Traditionally, bowel cancer is detected through colonoscopy. However, the method can miss up to 20% of precancerous cells. The process uses a traditional camera to image within the intestine, and then a growth is surgically cut away for inspection and analysis.

The imaging system the team developed is able to remove the surgical step by enabling in vivo analysis of growths.

Diagnosing bowel cancer can be a difficult procedure for clinicians: When examining polyps — clusters of cells that form along the ridges of the colon that could go on to develop cancer — doctors can sometimes miss a precancerous growth. When polyps are smaller than 10 mm in diameter, multiple in number, or flat in appearance, they are often associated with a higher miss rate.

“It is tough to discriminate serrated lesion from hyperplastic polyps,” said Peter Andersen, coordinator of the project, from the Technical University of Denmark.

Andersen described the concept as the “Google Earth” of colonoscopies.

“We start with a map of the country and then zoom in to a town, then a street, then a building. Similarly, our imaging procedure starts with conventional white light to identify a suspicious area a clinician would like to inspect further,” Andersen said. “Next, we can zoom in to the depth of the lesion using first OCT, then multiphoton microscopy for metabolic information, and finally Raman spectroscopy for molecular information (almost a molecular fingerprint of cancerous cells) to assess the suspected lesion.”

Cancerous cells have a higher metabolism than the noncancerous cells to which they are adjacent. This implies higher blood flow and vessel growth surrounding suspected lesions.

“Once zoomed in on a lesion at the cellular length scale, we can measure blood flow, metabolism, and molecular-specific information to identify cancerous lesions at cellular resolution,” Andersen said. “Our technology is, for the first time in colon inspections, an all-in-one device and, most importantly, label-free, meaning we do not have to inject a patient with dyes or biomarkers to flag up something suspicious.”

According to Andersen, only 14% of the EU population participates in screening programs, due to inconvenient tools and insufficient education or awareness. Concluding in 2024, the PROSCOPE project will conduct future trials at clinics at the Medical University of Vienna. The four-year project received a grant of 6 million euros ($7.01 million) from Horizon 2020 under the Research and Innovation action funding scheme. The project is coordinated from the Technical University of Denmark, with partners at the Medical University of Vienna, the University of St. Andrews, M-Squared Lasers, the University of Freiburg, Grintech, Ovesco Endoscopy, and the German Institute for Standardization.