Researchers develop optical biopsy system that detects liver cancer
New instrument could aid diagnosis by helping surgeons pinpoint the best
place for a biopsy

Date:
January 10, 2022
Source:
Optica
Summary:
Researchers have developed an optical biopsy system that can
distinguish between cancerous and healthy liver tissue. The
technology makes use of diffuse reflectance spectroscopy and
lifetime fluorescence measurements to evaluate makers of cellular
metabolism that differ between healthy and cancerous cells. The
system has higher accuracy than traditional biopsies, possibly
making liver cancer diagnosis easier.



FULL STORY ========================================================================== Researchers have developed an optical biopsy system that can distinguish between cancerous and healthy liver tissue. The new technology could
make it easier to diagnose liver cancer, which is the sixth most common
cancer globally.


==========================================================================
"The instrument is designed to be compatible with the needles currently
used for liver biopsies," said Evgenii Zherebtsov, a member of the
research team from Orel State University in Russia. "It could thus
one day help surgeons more precisely navigate the biopsy instrument to
decrease the number of errors in taking tissue samples that are used
for diagnosis." In the Optica Publishing Group journal Biomedical
Optics Express, the researchers report that the optical biopsy system
can reliably distinguish between cancerous and healthy cells in mouse
models. The system also showed promise in preliminary tests conducted
in people with suspected liver cancer.

"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, who was co-first author of the paper with
Zherebtsov.

"Although our system was specifically designed for use in abdominal
surgery, our results show that similar technologies could be useful
for other medical applications." Responding to a clinical need The
researchers designed the new device after the surgeons with which they
were collaborating noted how difficult it is to perform needle biopsies
in exactly the right location. Early-stage tumors can be hard to pinpoint
when inserting a tiny hollow needle into the liver to acquire a tissue
sample. If the needle is placed incorrectly and misses the tumor, it
could lead to an incorrect diagnosis.



==========================================================================
The new optical biopsy system combines diffuse reflectance spectroscopy
and lifetime fluorescence measurements to evaluate markers related
to cellular metabolism, which differs between healthy and cancerous
cells. This could help surgeons see, in real time, where the cancer is
so that they can identify the best place to acquire a tissue sample.

Diffuse reflectance spectroscopy reveals tissue properties based on how
they reflect light. Fluorescence lifetime analysis exposes tissues to a wavelength of light that induces fluorescence and then measures how long
that fluorescence takes to fade. The timing of the fluorescence decay
depends on the presence of molecules that are important in metabolism.

"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." With a focus on using the new instrument
to guide future biopsies in the clinic, the researchers selected compact, modern components for the device. The 1-millimeter-diameter probe is
compatible with a standard 17.5G biopsy needle and has separate optical channels for diffuse reflectance spectroscopy and fluorescence lifetime measurements.

Taking the probe to the clinic To assess the sensitivity of the assembled system, the researchers first measured known solutions of molecules that
play key roles in metabolism. Once they obtained satisfactory results,
they then performed experiments in a mouse model with liver cancer and preliminary measurements in patients with suspected liver cancer. The researchers found that their instrument and the parameters they measured
could reliably distinguish liver cancer tissue, healthy liver tissue
and the metabolically changed liver tissues that surround a tumor.

"It was important to us to compile a comprehensive picture of the
observed changes for cancer in both the mouse model and the clinical
setting," said Zherebtsov. "Our studies in patients who had the same
type of tumor as the mice showed that our technique can provide stable, reproducible results that can be used to detect cancer." The researchers
plan to continue measuring fluorescence lifetime parameters in patients
with different types of tumors at different stages to generate real-
time diagnostic classifiers. This will also make it possible to apply
advanced machine learning methods that could help surgeons make clinical decisions during a biopsy procedure.

========================================================================== Story Source: Materials provided by Optica. Note: Content may be edited
for style and length.


========================================================================== Journal Reference:
1. Evgenii A. Zherebtsov, Elena V. Potapova, Andrian V. Mamoshin,
Valery V.

Shupletsov, Ksenia Y. Kandurova, Viktor V. Dremin, Andrey
Y. Abramov, Andrey V. Dunaev. Fluorescence lifetime needle optical
biopsy discriminates hepatocellular carcinoma. Biomedical Optics
Express, 2022; 13 (2): 633 DOI: 10.1364/BOE.447687 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/01/220110114154.htm
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