2 min readSpecial Camera Detects Tumour
Munich, Germany – Cancer patients have the highest probability of recovering if tumours are completely removed. However, tiny clusters of cancer cells are often difficult for surgeons to recognize and remove. A camera makes hidden tumours visible during an operation.
Tumour removal surgeries pose a great challenge even to skillful and experienced surgeons. For one thing, tumour margins are blending into healthy tissue and are difficult to differentiate. For another, distributed domains of cancer and pre-malignancies are difficult to recognize. Up to now, doctors depend exclusively upon their trained eyes when excising pieces of tumours. In future, a new special camera system can help visualize during operation even the smallest, easy-to-overlook malignant pieces of tumour and thereby support the surgeons during complicated inter- ventions.
The trick: the camera can display fluorescent molecules that “paint” the cancer tissue. These are injected into the patients blood circulation prior to the operation and selectively attach onto the tumour during their trip through the body. If the corresponding area is then illumimated with a specific wavelength, fluorescence is emitted and the malignant tissue glows green, blue, red, or any other colour, depending on the injected dye, while the healthy tissue appears the same. In this way, the surgeon can see clusters of tumours cells that cannot be recognized by the naked eye.
New system reveals several dyes simultaneously
Researchers at the Fraunhofer Project Group for Automation in Medicine and Biotechnology (PAMB), which belongs to the Fraunhofer Institute for Manufacturing Engineering and Automation (IPA), have developed a new surgical aid, a multispectral fluorescence camera system. In the future, this special camera will integrate into various medical imaging systems such as, surgical microscopes and endoscopes, etc. The scientists from Mann- heim, Germany, will make the debute of a prototype of this high-tech system at the Medica Trade Fair in Düsseldorf in the joint Fraunhofer booth (Halle 10, Booth F05) between 20-23 November. The novel aspect about this camera: it can display several fluorescent dyes and the reflectance image simultaneously in real time – systems available until now have not been able to achieve this. The advantage: arteries and delicate nerves that must not be injured during an intervention can likewise be coloured with dye. They too can then be detected with the new camera, since they are set apart from their surroundings.
“The visibility of the dye to the camera depends in large part on the selection of the correct set of fluorescence filters. The filter separates the incident excitation wave- lengths from the fluorescing wavelengths so that the diseased tissue is also set apart from its surroundings, even at very low light intensities,” says Nikolas Dimitriadis, a scientist at PAMB. The researchers and their colleague require only one camera and one set of filters for their photographs, which can present up to four dyes at the same time. Software developed in-house analyses and processes the images in seconds and presents it continuously on a monitor during surgery. The information from the fluorescent image is superposed on the normal colour image. “The operator receives significantly more accurate information. Millimetre-sized tumour remnants or metastases that a surgeon would otherwise possibly overlook are recognizable in detail on the monitor. Patients operated under fluorescent light have improved chances of survival,” says Dr. Nikolas Dimitriadis, head of the Biomedical Optics Group at PAMB.
In order to be able to employ the multispectral fluorescence camera system as adapt- ably as possible, it can be converted to other combinations of dyes. “One preparation that is already available to make tumours visible is 5-amino levulinic acid (5-ALA). Physicians employ this especially for glioblastomas – one of the most frequent malignant brain tumours in adults,” explains Dimitriadis. 5-ALA leads to an accumulation of a red dye in the tumour and can likewise be detected with the camera. The multispectral fluorescence imaging system should have passed testing for use with humans as soon as next year. The first clinical tests with patients suffering from glioblastomas are planned for 2014.
Adapted from Fraunhofer-Gesellschaft.