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.