Imaging system has its sight set on cancerous tumours

Surgeons could receive support from a multispectral fluorescence imaging system developed by a team of researchers in Munich headed by Vasilis Ntziachristos, a professor of biological imaging.

According to a statement, a study carried out on nine patients with ovarian cancer has shown that the system can be used to localise cancer cells during surgery.

Before the operation, the patients were injected with folic acid chemically coupled to a green fluorescent dye. Most ovarian tumours have a protein molecule on their surface that bonds with folic acid and transports it inside the cell.

During abdominal surgery, the surgeon can then shine a laser light onto the patient’s ovaries, causing the green-labelled folic acid inside the cancer cells to emit light while healthy tissue remains dark. The fluorescent cancer cells, however, cannot be detected by eye.

Three cameras, mounted on a pivoting support arm over the operating table, detect optical and fluorescent signals at multiple spectral bands and then correct for light variations due to illumination and tissue discolourations in order to provide truly accurate fluorescence images that can be simultaneously displayed with corresponding colour images on monitors in the operating room.

The surgeon can check whether all the cancer cells have been removed by inspecting for remnant fluorescence light.

In eight of the nine patients, doctors were able to remove small clusters of tumour cells that might otherwise have gone undetected.

The multispectral fluorescence imaging system has passed its first OR test. However, it will have to prove its value to improve clinical outcome in further operations before it can be deployed for routine surgical procedures.

The researchers from Technische Universitaet Muenchen, Helmholtz Zentrum Muenchen and University of Groningen also want to further develop the camera system so it can be used to detect other forms of tumours during operations.