Surgery: "Our camera detects the tiniest remainder of a tumor"

Interview with Nikolas Dimitriadis, research group "Biomedical Optics", Fraunhofer Institute for Production Technology and Automation (IPA)

Differentiating tumor tissue from healthy tissue isn’t always easy for surgeons. Scattered cancer cells and early cancer are often hard to detect with the naked eye. A special camera now makes even the tiniest remainder of a tumor visible during surgery.


Photo: Nikolas Dimitriadis

Nikolas Dimitriadis; ©Konrad Gös

Nikolas Dimitriadis is a member of the "Biomedical Optics" research group at the Fraunhofer Institute for Production Technology and Automation (IPA), which developed this new camera system. He tells what role fluorescent dyes play in the system and explains how they affect the human body.

Mr. Dimitriadis, you and your colleagues developed a new camera that detects tumors during surgery. How does this camera work?

Nikolas Dimitriadis: You inject the patient with a fluorescent dye mixed with antibodies or other substances that are able to adhere to a tumor or other targeted tissue. The dye then accumulates at this spot. Our camera is now able to record a normal colored picture and an additional fluorescent image. The fluorescent images are then superimposed onto the normal picture, so they stand out from the normal tissue.

What makes our system so special is that it is able to record and show several dyes simultaneously and that it works in real time. Software we developed analyzes and processes the images in a few milliseconds and continuously presents them on a monitor during the surgery.

For what types of surgery and cancers is this technology best suited?

Dimitriadis: This technology essentially lends itself to all tumor surgeries for which fluorescent dyes with antibodies are available. Special antibodies are needed for each tissue. We can still expect further developments in this regard over the next few years.
Photo: Fluorescent tissue; Copyright: Fraunhofer IPA

The new camera shows colored structures with fluorescent dyes (here: blue and green areas); ©Fraunhofer IPA

What effect do the dyes have on human tissue?

Dimitriadis: The injected fluorescent dyes are of chemical origin and need to be approved as a pharmaceutical product. Their effectiveness and compatibility with the body are thus being tested.

The dyes accumulate in the tissue – this can be a tumor or a nerve for instance. When the respective area is then radiated with wavelength-specific light, fluorescence is activated and the malignant tissue glows green, blue, red or any other color – depending on the dye used. However, the appearance of the tissue remains unchanged to the naked eye, since fluorescent light is far too weak to be perceived by the eye. Yet the surgeon is able to see via the camera system where the dyed tumor or nerve runs, which he/she would not be able to see with the naked eye. You can also illustrate blood vessels the same way and obtain information on blood flow. Over time, the dyes are then broken down by the body or eliminated.

How can you insert the camera system into the tissue?

Dimitriadis: After the fluorescent dyes with the antibodies have accumulated in the tissue - this can take minutes or hours – our camera system comes into play. It could be embedded in the tip of an endoscope or surgical microscope for example.

Is it also possible to convert the camera system to work with other dye combinations?

Dimitriadis: It is easy to convert the camera system for different dye combinations. 5-Aminolevulinic acid or 5-ALA is an already available substance that is able to make tumors visible. Physicians use it particularly for glioblastomas – one of the most common malignant brain tumors in adults. 5-ALA leads to the accumulation of red dye in the tumor and can also be detected with the camera. Based on this procedure, we would like to demonstrate our camera technology during a live surgery next year.
Foto: Michalina Chrzanowska; Copyright: B. Frommann

© B. Frommann

The interview was conducted by Michalina Chrzanowska and translated by Elena O'Meara.