Source: www.biophotonics.world
Author: Sven Döring

Progress can be measured in two steps in Tobias Meyer’s laser laboratory and can be seen at a glance. In the background is a silver trolley, on top of it two black boxes and a monitor. The matt black compact device on the optical table in front of it is not even a fourth of it in site. Two Medicars, version 2015 and version 2019: a compact microscope for rapid cancer diagnosis during surgery.

“Good news from German cancer research” was the announcement by the German government in August 2019, referring to the “precision through laser light” with which the microscope researched at Leibniz IPHT makes cancerous tissue visible, enabling surgeons to remove tumors even more precisely in the future. The black box contains a light-based tool that can be used to examine the chemical and morphological composition of the tissue. This information is evaluated with artificial intelligence and immediately indicates whether the tumor has been completely removed – in other words, whether the operation was successful.

Tobias Meyer and his team from Leibniz IPHT, Friedrich Schiller University Jena, Jena University Hospital and the Fraunhofer Institute for Applied Optics and Precision Engineering are already continuing their research. They are combining the imaging procedure with a minimally invasive surgical precision tool: for laser-based microsurgery – and a new way to treat cancer in a gentle way. “Our vision,” as Scientific Director Jürgen Popp describes it, “is to use light not only to identify the tumor, but to directly remove it.”

For this purpose, the research team combined CARS imaging with a femtosecond laser for tissue ablation for the first time. Femtosecond laser ablation in which tissue is ablated using pulsed laser radiation, i. e. vaporized, is currently the most precise surgical tool established in ophthalmology, explains Tobias Meyer. On the basis of high-resolution, label-free CARS imaging the researchers were able to selectively ablate smaller, pathologically altered areas in different tissue types with micrometer precision.

The research team is now further developing this approach together with long-standing partners from the University Hospital Jena, the Jena optics companies Grintech and Active Fiber Systems and the globally operating endoscope manufacturer Karl Storz. The aim of the Thera- Optik project (Multimodal Endoscopic Accompanied by the fiber technologists at Leibniz IPHT, the team is now researching solutions to increase the ablation rates and make the lasers even smaller.

At the end of the project, a device is to be developed which, using a combination of endoscope, ablation laser, and hyperspectral wide-field im- aging, will make it possible to treat tumors at sensitive sites gently and precisely. “With this method, we can achieve resolutions in the range of a single cell,” explains Tobias Meyer. “This means that we can selectively remove one cell layer without touching the next one and thus ablate the tumor layer by layer”. Especially in the case of tumors at functional sites in the head and neck area, for example on the vocal cords or along the nerve tracts, this could significantly improve current treatment options and the chances of cure for patients.

Source: Leibniz IPHT