Gastroenterologist Mark Schattner discusses how endoscopic ultrasound (EUS) has expanded from a diagnostic technique to a staging and treatment tool for gastrointestinal cancers. EUS is a minimally invasive way to visualize superficial lesions, masses within the digestive wall, and organs adjacent to the area being examined. EUS-guided needle biopsy is used to extract tissue for analysis from the lymph nodes, as well as from organs such as the pancreas. Memorial Sloan Kettering endoscopists also use EUS to perform celiac plexus neurolysis, a technique for alleviating severe abdominal pain from pancreatic cancer that can in some cases reduce the patient’s need for opiates. Memorial Sloan Kettering’s team performs 400 to 500 EUS procedures annually, and the figure is expected to grow.