A study found that endoscopic ultrasound (EUS) works better than traditional methods in lung cancer diagnosis, according to The Chinese University of Hong Kong which made the result public on Thursday.

The university's Faculty of Medicine recruited 125 patients with abnormal shadows on chest X-ray were recruited from 1998 to 2007, to assess the diagnostic yield and complication rate of EUS for various suspicious lesions in the chest.

The diagnosis in about half of these patients remained obscure despite conventional investigations. Using EUS, the causes of abnormal chest X-ray shadows in 83 percent of the cases were established. Complication rate was very low, smaller than 1 percent, and there was no procedure-related fatality.

"This study suggests that, EUS is an important diagnostic and staging tool for lung cancer patients. It is safe, accurate, and highly tolerable," said Dr. Larry Lai, the in-charge endoscopist in EUS service and Honorary Clinical Tutor of the Department of Medicine and Therapeutics of the university.

Traditionally, clinicians use computer tomography (CT) scan, bronchoscopy, or even operation under general anesthesia to evaluate the extent of cancer invasion. However, these conventional techniques are often traumatic.

EUS is a flexible endoscope coupled with a small ultrasound device at its tip. It is inserted through the patient's mouth into the esophagus and stomach and generates ultrasound wave, which penetrates the wall of the gut and produces visual images of the surrounding internal organs.

Because of the close proximity, the image quality is much better than CT scan. Moreover, EUS can safely sample abnormal lymph nodes and lung tissues through the esophagus without the need of general anesthesia or open surgery.

Prince of Wales Hospital, the teaching hospital of the Chinese University, was the first center that introduced this novel investigation in Hong Kong, and it is now one of the leading EUS centers in Asia.

According to Hong Kong Cancer Registry, lung cancer is the most common malignancy in the territory, with more than 4,000 new cases every year.

(Xinhua News Agency February 6, 2009)