Researchers at Orel State University in Russia have developed a biopsy system that can distinguish between healthy and cancerous tissue in many clinical cases. The device is designed to address the difficulties that clinicians may experience when trying to obtain a biopsy of a liver tumor, where it can be difficult to know if the needle is in the correct location with small, early-stage tumors. The system uses a combination of lifetime fluorescence measurements and diffuse reflectance spectroscopy to identify a tumor.
Obtaining a tumor biopsy is an important first step in identifying its characteristics, allowing clinicians to plan treatments accordingly. However, it can be difficult to know for sure that the tissue you have just removed using a hollow needle actually comes from the tumor itself, particularly if the tumor is small and within the abdominal cavity.
These Russian researchers have designed a biopsy system that could provide a helping hand. “Optical biopsy methods like the one we developed make it possible to differentiate healthy and tumor tissues with a high degree of accuracy,” said Elena V. Potapova, a researcher involved in this latest study. “Although our system was specifically designed for use in abdominal surgery, our results show that similar technologies could be useful for other medical applications.”
The technology combines two different modalities to identify tumor tissues in near real time. The first is diffuse reflectance spectroscopy, which measures how the tested tissue reflects light, and the second is called fluorescence lifetime analysis. This involves inducing fluorescence by shining a specific wavelength of light onto a tissue, and then calculating how long it takes for the fluorescent signal to disappear.
Molecules that are involved in cell metabolism within a tissue affect how long the fluorescence sticks around. As cancer cells have significantly altered metabolism, the technique is useful for a quick determination of cancer status. “Although our team as well as others have previously used fluorescence intensity for tissue assessment, studies performed in other parts of the body have shown that fluorescence lifetime is less dependent on experimental conditions,” said Potapova. “Fluorescence lifetime measurements remain more consistent in the presence of blood, when there is non-uniform illumination, or if the contact between the probe and tissue changes due to movement.”
The probe is just 1 mm in diameter and the system is compatible with standard 17.5G biopsy needles.
Study in Biomedical Optics Express: Fluorescence lifetime needle optical biopsy discriminates hepatocellular carcinoma