Optical Technique Allows Non-Surgical Biopsies

June 27, 1997

A team of researchers from the Massachusetts Institute of Technology and Massachusetts General Hospital have developed a non-invasive method of detecting early signs of cancer and heart attacks, Science magazine reported today. The new method, known as optical coherence tomography (OCT), produces a clear picture of a cross-section of bodily tissue without requiring surgical biopsy. Using laser light, OCT can magnify tissue to allow visualization of individual cells without damaging the tissue.

OCT is based on optical fiber technology, the same technology now used in telecommunications. An optical fiber is a string-like component that guides light waves, allowing a light beam to be controlled over long distances and around bends.

OCT can be compared to ultrasound, except that infrared light waves are used rather than acoustic waves. Ultrasound sends out waves of sound and interprets the echoes reflected back by structures to create a visual image. A ship's sonar, for example, reveals the ragged terrain of the ocean far below it.

Similarly, OCT shines a beam of infrared light into tissue structure, and its backreflections, measured from different positions, form an image of the terrain within. Thanks to OCT's high resolution -- ten times higher than either clinical MRI or high-frequency ultrasound -- microscopic early signs of disruption in tissue terrain can be detected and possibly treated. The infrared light used in OCT is introduced to tissue by means of a small catheter or endoscope, which can be used practically anywhere in the body.

Seven authors are credited for the article in Science, titled "In Vivo Endoscopic Optical Biopsy with Optical Coherence Tomography." They are senior author James G. Fujimoto, PhD, Professor in the Research Laboratory of Electronics and in the Department of Electrical Engineering and Computer Science at MIT; Guillermo J. Tearney (first author), Brett E. Bouma, Stephen A. Boppart, and Costas Pitris, all graduate student in the MIT Department of Electrical Engineering and Computer Science; and Mark E. Brezinski, MD, an MGH cardiologist.

The program for developing OCT had two stages, the first of which involved imaging of transparent tissue. This began in 1991 in Professor Fujimoto's laboratory at MIT, in collaboration with Carmen A. Puliafito, MD, director of the New England Eye Center and chairman of Ophthalmology at Tufts University School of Medicine. OCT imaging of the retina provides a "very powerful tool for ophthalmic diagnostics, especially for conditions such as glaucoma and macular edema," says Professor Fujimoto. To date, several thousand patients have been examined using OCT. The results suggest OCT may be a promising way to diagnose early-stage glaucoma.

In 1994, in a collaboration led by Professor Fujimoto and Dr. Brezinski, OCT imaging was developed for optical biopsy in nontransparent tissue, which represents most of the tissue of the body. In the Science article, the researchers discuss using OCT to image the esophagus of a living rabbit. "The key advance described in this article is the demonstration of OCT for imaging nontransparent tissue in vivo [in a living organism]," says Professor Fujimoto. "This advance opens up the possibility of an incredibly broad range of clinical applications."

Developing OCT to its current status required persistence and an effective collaboration among researchers. "Three and a half years ago, I was told by many people that this project wouldn't work, that light wouldn't penetrate deeply enough. Now we are just about ready to test OCT in patients through a high-speed, high-resolution catheter/endoscope-based system," says Dr. Brezinski, who also is an assistant professor of Medicine at Harvard Medical School and a research affiliate in the MIT Research Laboratory of Electronics and the Department of Electrical Engineering and Computer Science. "This could not have been accomplished by one or two individuals but represented the vertical integration of students, postdocs and investigators, a fact of which we are all very proud. If you compare this to other technologies like ultrasound and MRI, we have come a tremendous way in three and a half years.

The researchers suggest that OCT may replace conventional biopsy for many applications in the future. First, OCT can be used where conventional biopsy would be hazardous, with the brain and coronary arteries being the most prominent examples. Second, OCT could serve well where surgical biopsy can miss the diagnosis, such as in early cancer detection in the colon, esophagus and cervix. Third, they suggest, OCT can be used to guide surgical and microsurgical procedures, such a nerve repair or prostate surgery.

Further research with OCT includes working directly with patients; increasing the resolution to allow OCT to be applied to early diagnosis of such disorders as cervical cancer; and exploring technologies to use with OCT -- such as spectroscopy, which may allow biochemical as well as structural information to be gained from the tissue.

The National Institutes of Health, the Office for Naval Research and the Whittaker Foundation provided funding for the research described in Science.

###




Massachusetts General Hospital

Related Cancer Articles from Brightsurf:

New blood cancer treatment works by selectively interfering with cancer cell signalling
University of Alberta scientists have identified the mechanism of action behind a new type of precision cancer drug for blood cancers that is set for human trials, according to research published in Nature Communications.

UCI researchers uncover cancer cell vulnerabilities; may lead to better cancer therapies
A new University of California, Irvine-led study reveals a protein responsible for genetic changes resulting in a variety of cancers, may also be the key to more effective, targeted cancer therapy.

Breast cancer treatment costs highest among young women with metastic cancer
In a fight for their lives, young women, age 18-44, spend double the amount of older women to survive metastatic breast cancer, according to a large statewide study by the University of North Carolina at Chapel Hill.

Cancer mortality continues steady decline, driven by progress against lung cancer
The cancer death rate declined by 29% from 1991 to 2017, including a 2.2% drop from 2016 to 2017, the largest single-year drop in cancer mortality ever reported.

Stress in cervical cancer patients associated with higher risk of cancer-specific mortality
Psychological stress was associated with a higher risk of cancer-specific mortality in women diagnosed with cervical cancer.

Cancer-sniffing dogs 97% accurate in identifying lung cancer, according to study in JAOA
The next step will be to further fractionate the samples based on chemical and physical properties, presenting them back to the dogs until the specific biomarkers for each cancer are identified.

Moffitt Cancer Center researchers identify one way T cell function may fail in cancer
Moffitt Cancer Center researchers have discovered a mechanism by which one type of immune cell, CD8+ T cells, can become dysfunctional, impeding its ability to seek and kill cancer cells.

More cancer survivors, fewer cancer specialists point to challenge in meeting care needs
An aging population, a growing number of cancer survivors, and a projected shortage of cancer care providers will result in a challenge in delivering the care for cancer survivors in the United States if systemic changes are not made.

New cancer vaccine platform a potential tool for efficacious targeted cancer therapy
Researchers at the University of Helsinki have discovered a solution in the form of a cancer vaccine platform for improving the efficacy of oncolytic viruses used in cancer treatment.

American Cancer Society outlines blueprint for cancer control in the 21st century
The American Cancer Society is outlining its vision for cancer control in the decades ahead in a series of articles that forms the basis of a national cancer control plan.

Read More: Cancer News and Cancer Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.