Advancements in the Endoscopy Suite

Advancing Technology Behind Fluorescence Bronchoscopy

Lung cancer is the most lethal form of cancer in the United States. According to research from the American College of Chest Physicians, less than 15 percent of invasive lung cancer patients survive five years after treatment. Advances in diagnostic and treatment options are critical.

Illuminating the Specifics

Researchers at Xillix Technologies Corporation in Richmond, British Columbia, presented their diagnostic solution to the U.S. Food and Drug Administration (FDA). The Life-Lung fluorescence imaging device, which includes a camera, light source and controller, received approval in 1996. With the device, endoscopy team members can use an Olympus bronchoscope to determine if a patient has lung cancer by examining the color of the lung tissue once illuminated by the fluorescence system.

"It works on the principle of autofluorescence," says Shane Gendron, chief of investor relations at Xillix. "Different emissions come from different tissues. When tissue is shined upon with our patented blue light, healthy tissue fluoresces a greenish color. Any area of precancerous tissue fluoresces a different color, more of a reddish-brown."

Research has shown when tissue is illuminated with violet or blue light (400 to 450 nm), normal tissue will respond with a strong green color (500 to 520 nm). Tissue has this ability to illuminate because of the absorption of chromophores. Frequently, chromophores are present in lung tissue include elastin, collagen, flavins, nicotinamide-adenine dinucleotide (NAD) and porphyrins. When these cells are excited by exposure to wavelengths of higher electronic states, they begin to illuminate. The subepithelial and epithelium itself are involved in this fluorescence.¹

According to Xillix officials, the technology improves lung cancer detection by more than 171 percent. The journal Chest reported the system is 530 percent better than a standard white-light bronchoscopy.

Since the first generation device's approval in 1996, Xillix and its previous distributor, Olympus America Inc., have severed their business ties. The third generation of the device, now with the capability of working with many endoscopes, will soon go before the FDA for a new round of trials.

"In 1999, we entered into an international arbitration with our former business partner," Gendron says. "We no longer produce or manufacture the Life-Lung system. We are in a latter stage of development for Onco-LIFE, which is based on the same technology. It has been designed as a platform technology for the lung and gastrointestinal tract. It will have plug-and-play capabilities with an array of endoscopes and accessories."

Industry Opinions

Jim Slattery, AD, RN, CGRN, is an endoscopy nurse at Brigham and Women's Hospital in Boston. He has presented about the procedure and says, like any technological advance, it has quirks.

"Blood appears deeper red-brown and inflamed tissue appears nearly red-brown," he says. "There can be some limitations in the interpretation of the color changes visualized."

However, Slattery says the tool highlights the importance of diagnosing cancer early on.

"The procedure is used to follow up on lung cancer patients who have had a resection," he says. "Studies are underway to show the efficacy of fluorescence bronchoscopy as a screening tool in patients at high risk for lung cancer, such as those with family history and smokers. Areas that show up red-brown can be biopsied for dysplasia. The goal is to find lung cancer at its earliest stages so curative techniques such as photodynamic therapy, radiation or early surgical intervention can be used."

Slattery says proper patient preparation is key.

"Patient preparation is the same for patients undergoing a standard bronchoscopy," he says. "Special attention provides excellent oropharyngeal and endobronchial anesthesia with lidocaine, and fentanyl citrate suppresses cough. Coughing can and does cause irritation in the bronchi and can be misread. The patient first undergoes standard white-light bronchoscopy to rule out obvious lesions. With the scope still in the trachea, the system is attached to the scope and the blue light is turned on. The bronchial tree is then re-examined to look for suspicious areas. Endobronchial biopsies are then taken either with blue-light or white-light bronchoscopy, depending on the site."

This technology allows endoscopy team members to visualize and biopsy carcinoma in situ. If the cancer has spread past the cartilage layer, it is usually not treatable and resection may be necessary. The depth of the disease can be determined by an endoscopic ultrasound.¹

Because bronchial cancer cells are so small, 8 mm on average, they can go undetected. Research has shown 30 percent of these cells are visible to bronchoscopists during a traditional white-light bronchoscopy.¹

Equipment Details

This technology is precise and pricey, Slattery says."The initial cost of equipment is quite high, so any endoscopy unit considering fluorescence bronchoscopy would need high patient volume to have it ear its keep," he says. "The jury is still out as to its value as a screening tool. It may be better to know of a large (medical) center that has the equipment and refer patients to the center with the technology.

Gendron says the Xillix system is comparable to other white-light systems.

"Final pricing has not been set," she says, "But it will be in the $50,000 to $70,000 range." She says the company estimates trials for the lung system will begin this fall, with approval expected by mid-2003, when trials of the gastrointestinal system would begin. Today, there are 130 facilities worldwide using the first generation system.

Additional systems include the Pentax SAFE-1000 and the Karl Storz D-Light system.

"The best teaching tool regarding this procedure is to let people know the+ technology exists and where to refer post-operative cancer patients for follow up exams," Slattery says.

Photo Dynamic Diagnosis For Early Recognition Of Carcinoma Of the Bladder

White light: Recurring carcinoma of the bladder	Fluorescent excitation:  Red fluorescent dysplasia in resected tumor
Recurring carcinoma of the bladder	Red fluorescent carcinoma in situ
Recurring carcinoma of the bladder	Red fluorescent papillary tumor

Resource Guide

The following Web sites have information concerning fluorescence bronchoscopy.

Beth Israel Deaconess Medical Center, Center for Thoracic Diseases
www.bidmc.harvard.edu/
thoracic_center/spotlight.htm

American College of Chest Physicians
www.chestnet.org/education/
pccu/vol15/lesson08.html

Swiss Federal Institute of Technology
www.polus.net/ASPHome/Meetings/
Annual2000/Wednesday/view_abstract657.html   

Allegheny General Hospital, Division of Respiratory Diseases
www.lunglinks.com/phnews/4/Sub4.htm

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