Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Fluorescence Spectroscopy Can Distinguish Brain Tumor From Normal Tissue

02.08.2004


When molecules in cells are stimulated by light, they respond by becoming excited and re-emitting light of varying colors (fluorescence) that can be captured and measured by highly sensitive optical equipment.



Now, researchers at Cedars-Sinai Medical Center and the University of Southern California are developing miniaturized spectroscopic instruments and computer software to take a real-time look at biochemical, functional and structural changes occurring within the cells and tissue of the brain. If the technology continues to progress as anticipated, neurosurgeons will be able to shine a light during surgery to diagnose brain tumors instantaneously and they will be able to discern the borders of tumors with greater precision than ever.

Early studies appear to support these possibilities. The researchers report in the July/August issue of Photochemistry and Photobiology that the techniques and device they have developed are able to quickly and accurately discriminate between brain tumor and normal tissue.


Glioblastoma multiforme (GBM), the most common and deadly type of brain tumor, was the subject of the study. Because these tumors grow quickly and invade healthy tissue rapidly, patient survival rates usually are measured in weeks or months despite aggressive treatment with traditional surgery, chemotherapy and radiation. When “image complete” resection is accomplished – no remaining tumor is visible with high-resolution imaging techniques – patients have a median survival of about 70 weeks.

But complete removal is nearly impossible because the tumors aggressively infiltrate neighboring tissue and are irregularly shaped with poorly defined borders. Also, tumor cells tend to migrate away to establish satellites in other parts of the brain. When surgical removal is less than image complete, median survival is less than 19 weeks.

“Although our surgical goal is to remove as much tumor as possible without damaging healthy brain, distinguishing between the two is extremely difficult,” said Keith L. Black, MD, neurosurgeon, director of the Maxine Dunitz Neurosurgical Institute, the Division of Neurosurgery and the Comprehensive Brain Tumor Program.

“Fluorescence spectroscopy is one of several innovative imaging techniques in development, and I think the evolution of this capability comes at a critical time because we are beginning to see encouraging results in several therapeutic approaches,” continued Dr. Black, who holds the Ruth and Lawrence Harvey Chair in Neuroscience at Cedars-Sinai and is one of the journal article’s authors. “The clarity that fluorescence technology appears to offer may provide greater precision in surgery and also help us target cancer cells with a combination of new, highly focused therapies.”

The ability to immediately analyze cells revolves around the fact that different metabolic states and biochemical components emit light differently. Just as a prism splits white light into a full spectrum of color, laser light focused on tissue is re-emitted in colors determined by the properties of the molecules. Analyzing the colors in space and time provides information about the types of molecules present and their conformation.

“With time-resolved laser-induced fluorescence spectroscopy we measure both the wavelength of the emission and the time that molecules stay in the excited state before returning to the ground state. This provides information about the chemical composition of the tissue, about molecular and biochemical changes, as a function of the stages of disease,” said Laura Marcu, PhD, director of the Biophotonics Research and Technology Development Laboratory at Cedars-Sinai.

A research associate professor of electrical and biomedical engineering at USC’s Viterbi School of Engineering, Dr. Marcu is directing several USC graduate students and postdoctoral fellows in the creation of the optical imaging devices, hardware and software. She is working in conjunction with the neurosurgeons and researchers at the Maxine Dunitz Neurosurgical Institute to adapt the system’s clinical applications to central nervous system tissue, and is collaborating with cardiologists to pursue spectroscopic detection of atherosclerosis.

According to Dr. Marcu, first author of the article, the researchers found that high-grade gliomas are characterized by fluorescence emissions of longer duration overall, compared to those of normal tissue. Furthermore, gliomas can be distinguished by fluorescence lifetimes that differ at various wavelengths: glioma fluorescence is long-lived at certain short wavelengths but short-lived at some longer wavelengths. Analyzing the tissue in terms of both fluorescence intensity and fluorescence lifetime provides information that translates into a high level of diagnostic specificity.

Currently, the spectroscopic system consists of an optical instrument about the size of a ballpoint pen that is connected by a fiber-optic cable to a computer. Through a lens at the tip, the probe provides light and magnification for surgeons. Light from a nitrogen laser can be used to stimulate the molecules within cells and the light emitted from the cells is sent back to the data processing system.

The equipment is enabling the research teams to acquire accurate, repeatable measurements in living tissue and is serving as a prototype for future diagnostic technology. Dr. Marcu, a biomedical engineer specialized in optical spectroscopy and imaging, said a number of technological challenges are being addressed. “Most of the earlier investigations were done in my laboratory on the optical table,” she said. “Now we’re in a new stage in which we have put together optical instrumentation that can go onto a standard endoscopic cart in the operating room.”

Before fluorescence spectroscopy can become routine in the operating room, the equipment must be miniaturized and fine-tuned, and the information displayed must be simplified, said Dr. Marcu. “At present, we look at a computer screen that contains information about the tissue. But we hope to develop miniature systems that provide yes or no answers – perhaps a light that changes colors to show which tissue is healthy and which is diseased. It will recognize in real time the characteristics of the tissue.”

Cedars-Sinai’s Biophotonics Research Lab is affiliated with the Minimally Invasive Technologies Institute (MISTI) within the Department of Surgery. The MISTI brings together a scientific research group, a pre-clinical faculty and a clinical research team, all focusing on the development, testing and introduction of minimally invasive and noninvasive technologies into everyday surgical practice.

The fluorescence study was supported in part by the Whitaker Foundation.

Cedars-Sinai is one of the largest nonprofit academic medical centers in the Western United States. For the fifth straight two-year period, it has been named Southern California’s gold standard in health care in an independent survey. Cedars-Sinai is internationally renowned for its diagnostic and treatment capabilities and its broad spectrum of programs and services, as well as breakthroughs in biomedical research and superlative medical education. It ranks among the top 10 non-university hospitals in the nation for its research activities.

Sandy Van | Cedars-Sinai Medical Center
Further information:
http://www.csmc.edu

More articles from Life Sciences:

nachricht Russian scientists show changes in the erythrocyte nanostructure under stress
22.02.2019 | Lobachevsky University

nachricht How the intestinal fungus Candida albicans shapes our immune system
22.02.2019 | Exzellenzcluster Präzisionsmedizin für chronische Entzündungserkrankungen

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: (Re)solving the jet/cocoon riddle of a gravitational wave event

An international research team including astronomers from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has combined radio telescopes from five continents to prove the existence of a narrow stream of material, a so-called jet, emerging from the only gravitational wave event involving two neutron stars observed so far. With its high sensitivity and excellent performance, the 100-m radio telescope in Effelsberg played an important role in the observations.

In August 2017, two neutron stars were observed colliding, producing gravitational waves that were detected by the American LIGO and European Virgo detectors....

Im Focus: Light from a roll – hybrid OLED creates innovative and functional luminous surfaces

Up to now, OLEDs have been used exclusively as a novel lighting technology for use in luminaires and lamps. However, flexible organic technology can offer much more: as an active lighting surface, it can be combined with a wide variety of materials, not just to modify but to revolutionize the functionality and design of countless existing products. To exemplify this, the Fraunhofer FEP together with the company EMDE development of light GmbH will be presenting hybrid flexible OLEDs integrated into textile designs within the EU-funded project PI-SCALE for the first time at LOPEC (March 19-21, 2019 in Munich, Germany) as examples of some of the many possible applications.

The Fraunhofer FEP, a provider of research and development services in the field of organic electronics, has long been involved in the development of...

Im Focus: Regensburg physicists watch electron transfer in a single molecule

For the first time, an international team of scientists based in Regensburg, Germany, has recorded the orbitals of single molecules in different charge states in a novel type of microscopy. The research findings are published under the title “Mapping orbital changes upon electron transfer with tunneling microscopy on insulators” in the prestigious journal “Nature”.

The building blocks of matter surrounding us are atoms and molecules. The properties of that matter, however, are often not set by these building blocks...

Im Focus: University of Konstanz gains new insights into the recent development of the human immune system

Scientists at the University of Konstanz identify fierce competition between the human immune system and bacterial pathogens

Cell biologists from the University of Konstanz shed light on a recent evolutionary process in the human immune system and publish their findings in the...

Im Focus: Transformation through Light

Laser physicists have taken snapshots of carbon molecules C₆₀ showing how they transform in intense infrared light

When carbon molecules C₆₀ are exposed to an intense infrared light, they change their ball-like structure to a more elongated version. This has now been...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Global Legal Hackathon at HAW Hamburg

11.02.2019 | Event News

The world of quantum chemistry meets in Heidelberg

30.01.2019 | Event News

Our digital society in 2040

16.01.2019 | Event News

 
Latest News

JILA researchers make coldest quantum gas of molecules

22.02.2019 | Physics and Astronomy

Understanding high efficiency of deep ultraviolet LEDs

22.02.2019 | Materials Sciences

Russian scientists show changes in the erythrocyte nanostructure under stress

22.02.2019 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>