Light-Sheet Microscopy Method Improves Cancer Diagnostics

A microscopy technique developed by researchers at TU Wien (Austria) in collaboration with TU Munich could lead to more reliable cancer diagnostics. The technique allows a tumor to be analyzed after surgery in 3D without cutting the tumor into sections.

Previous methods for assessing the success of cancer surgery required pathologists to cut very thin sections, approximately 4 µm thick every 5 mm. These samples were then analyzed under a microscope to determine the presence or absence of cancer cells. That method examines only a very small amount of the tumor.

A chemically treated transparent tumor in the ultramicroscope, illuminated by the light sheet. Courtesy of TU Wien.

The technique developed by TU Wien and TU Munich researchers allows the tumor to be analyzed in 3D by making it transparent. Inna Sabdyusheva, who worked on the project in the context of her dissertation, developed a chemical process to “clear” breast cancer samples based on a technique developed by Klaus Becker, senior scientist at TU Wien. The process leaves the structure unchanged with the cancer cells still recognizable.

The sample is then analyzed under an ultramicroscope where a light sheet, a thin layer of laser beams, penetrates the tissue. The sample is analyzed layer by layer, so as to allow a computer to display any section through the tumor. An optical system developed by Saideh Saghafi, of the same research group, enabled the work by producing particularly long and thin light sheets.

A 3D image of a tumor produced through the innovative technique developed at TU Wien. Courtesy of TU Wien.

“In less time than before, greater reliability in examinations can be achieved,” said Hans-Ulrich Dodt, professor of bioelectronics at TU Wien. “In addition, the new 3D method should also provide completely new insights into cancer development in the future. Since it is now possible for the first time to display the spread of cancer cells in human surgical specimens in three dimensions, understanding of tumor biology should also make significant progress.”

Dodt envisions pathologists now having the ability to scroll through images with a mouse, similar to how radiologists currently work. He believes that the large amount of data produced through the process can open up opportunities in the artificial intelligence field as well.

“Perhaps such computer programs could speed up and simplify tumor diagnostics in the future,” Dodt said.

The research was published in Scientific Reports (www.doi.org/10.1038/s41598-020-71737-w).