Optical biopsy of early gastroesophageal cancer by catheter-based reflectance-type laser-scanning confocal microscopy

Magnified endoscopic observation of the gastrointestinal tract has become possible. However, such observation at the cellular level remains difficult. Laser-scanning confocal microscopy (LCM) is a novel, noninvasive optical imaging method that provides instant microscopic images of untreated tissue under endoscopy. We compared prototype catheter-based reflectance-type LCM images in vivo and histologic images of early gastroesophageal cancer to assess the usefulness of LCM in diagnosing such cancer. Twenty sites in the esophagus and 40 sites in the stomach were examined by LCM under endoscopy prior to endoscopic or surgical resection. A prototype catheter LCM system, equipped with a semiconductor laser that oscillates at 685 nm and analyzes reflected light (Mauna Kea Technologies, Paris, France; Fujinon, Saitama, Japan), was used in vivo without fluorescent agent. In all normal esophageal mucosa and esophageal cancers, the nuclei were visualized. In 9 of the 10 normal esophageal mucosa, cell membranes were visualized, and in 5 of the 10 esophageal cancers, cell membranes were visualized. In all normal gastric mucosa, nuclei and cell membranes were not visualized, but in 10 of the 20 gastric cancers, nuclei were visualized. This novel method will aid in immediate diagnosis under endoscopy without the need for biopsy