A New Tool for Non-Invasive Cancer Detection

A newly designed endoscope, capable of providing sub-second polarized spectral images of tissue in vivo, allows physicians and surgeons to non-invasively survey and sample an entire area without actually removing tissue, and may offer hope as a new tool for detecting cancer early. Researchers from Cedars-Sinai Medical Center in Los Angeles and Carnegie Mellon University in Pittsburgh described the instrument’s capabilities and clinical applications in the July 2004 issue of Progress in Biomedical Optics and Imaging.

The new device, named the Hyperspectral Imaging Endoscope (HSIE), is a standard medical endoscope enhanced with a customized imaging fiber. Working together with a camera, a laptop computer and a tunable light source covering the visible and near-infrared range, the HSIE system is capable of acquiring rapid spectral images of tissues, allowing physicians to noninvasively survey and sample an entire area of tissue in vivo. Compared to traditional biopsy where a small amount of tissue is removed and then examined in a laboratory, the HSIE system provides a non-contact method of gaining as much information as possible about an area without removing any tissue.

The system is relatively simple and based on the intrinsic properties of tissue and light, explains Daniel Farkas, PhD, director of the Minimally Invasive Surgical Technologies Institute at Cedars-Sinai, and one of the study authors. “When light impacts tissue, it gives back a certain scattering pattern with spectral oscillations depending on the size of the scattering object. This pattern gives us a relatively quantitative idea whether or not a tissue area contains cancerous cells since the nuclei of cells in pre-cancerous and cancerous tissues are enlarged. The theory and spectroscopy have been beautifully worked out by our colleagues in Boston and Los Alamos, and we have now moved this type of investigation into the endoscopic imaging domain.”

The pilot study using the HSIE system involved examining epithelial tissue derived from lung cancer specimens. Currently the No. 1 cause of cancer death worldwide, lung cancer is difficult to detect in its early stages and often isn’t found until after it has spread.

At the University of Pittsburgh Medical Center and Allegheny General Hospital, the two clinical sites where the first version of the HSIE instrument was tested, data were gathered from patients who had been treated previously for lung cancer and were to undergo an endoscopic examination to see if the cancer had returned. The area to be biopsied in the traditional way by the surgeon was first scanned using the HSIE, and then sent to the laboratory. The result of the pathological examination was then treated as “ground truth.” According to Farkas, there was a good correlation between the HSIE imaging and the pathologists’ diagnoses.

Based on the experience of physicians participating in the pilot study, Farkas anticipates that the medical community will embrace the new endoscope in its practices. “Physicians can use their own endoscope of choice exactly as they have before. By using this additional fiber, they’ll be able to have either two kinds of images on separate screens or overlay the spectrally classified image onto the regular image. In early acceptance stages, this could only guide biopsy, but as the matches with pathology are confirmed, the true diagnostic value of HSIE could be established.”

Farkas, a biophysicist and past Fulbright scholar, is the vice chair for research of Cedars-Sinai’s department of surgery as well as director of the Minimally Invasive Surgical Technologies Institute, which was formed in May 2002 to pursue the development and application of advanced technologies in surgery.

While epithelial tissue is the primary application, Farkas said the HSIE system can also be used for gastrointestinal investigations and maybe even for breast duct endoscopy.

“Surgery is clearly gravitating to the minimally invasive arena. The technology we employed in building the HSIE system gives us a great opportunity to improve a number of important components of surgical intervention. We are working now on an implementation using acousto-optic tunable filters, invented for hyperspectral satellite reconnaissance. It may sound like science fiction now, but I think we may ultimately be able to use the endoscope to not only detect cancers early, but to treat them using modalities such as localized photodynamic therapy, laser ablation or gene therapy. This closer coupling, spatially and temporally, between diagnosis and treatment may be the cornerstone of future surgical intervention.”

A new study published in The New England Journal of Medicine shows that rates of a recently identified and debilitating disorder called eosinophilic esophagitis have risen so dramatically in recent years that they may be at higher levels than that of other inflammatory gastrointestinal disorders, such as Crohn’s disease or ulcerative colitis.

“Despite this explosion in incidence rates, there is so little information available about the disease that patients often suffer for a number of years before a diagnosis is made,” says Marc E. Rothenbers, MD, PhD, director of allergy and immunology at Cincinnati Children’s Hospital Medical Center and the study’s senior author.

The researchers also discovered a familial pattern to the disease, which suggests either a genetic predisposition or a relationship to an unknown environmental exposure, either of which warrant further study, according to Rothenberg.

Eosinophilic esophagitis (EE) is characterized by severely elevated levels of eosinophils — a type of white blood cell — in the esophagus. These eosinophils grow in an uncontrolled manner and attack the gastrointestinal system, leading to vomiting and difficulty with growth and swallowing food (dysphagia).

EE differs from esophageal reflux in the magnitude of eosinophils that are recruited into the gastrointestinal tract and the lack of response to anti-reflux medications. EE is just one a group of disorders called eosinophilic gastrointestinal diseases that are often associated with allergies. EE is an emerging disease throughout the world, as documented by recent series of cases in the United States, England, Japan, Spain, Australia, Switzerland and Italy.

“This newly recognized eosinophil and possibly allergic-based GI disease is of great interest as it reflects, on an epidemiologic level, a worldwide increase of new allergic inflammation-based disorders,” says Lanny J. Rosenwasser, MD, the Marjorie and Stephen Raphael chair in asthma research and professor of allergy and immunology, at National Jewish Medical and Research Center in Denver. “Understanding the mechanisms and pathogenesis of these disorders is of pressing importance,” adds Rosenwasser, who was not involved in the study.

To determine the incidence of EE, Rothenberg and his colleagues at Cincinnati Children’s examined cases of EE in patients from Hamilton County that were identified at Cincinnati Children’s, which is the only provider in the region with a pediatric gastroenterology and pathology departments. Between 1991 and 2003, 315 cases met diagnostic criteria for EE, based on the pathology department’s database. Only 2.8 percent of these cases were identified prior to 2000. Of the 315 cases, 103 resided within the county.

Incidence rates of EE have not been reported in any other region of the United States, so national incidence rates are impossible to determine. If rates are the same as they are in Hamilton County, the annual occurrence of this disease would be one in every 10,000 children, or approximately 22,000 children in the United States, according to the researchers, who base that estimate on U.S. Census Data.

Families across the nation affected by this disease recently developed an organization to support increased public awareness and research initiatives, called the American Partnership for Eosiniphilic Disorders (APFED). The Campaign Urging Research for Eosinophilic Disorders (CURED) recently presented Rothenberg with $81,000 to be used exclusively as early seed money to support finding a cure for this disease.

Source: Cincinnati Children’s Hospital Medical Center

Upcoming Events

February 11-12, 2005
Central Illinois SGNA presents
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Carle Foundation Hospital, Urbana, Ill.
Cost is $45 for members, $55 for non-members and $25 for students/techs.
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February 19, 2005
Accredited IBD Symposium for Healthcare Professionals
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