Imaging in gastrointestinal cancer

Abstract

Routine and innovative imaging approaches are used for screening, diagnosis and staging, monitoring treatment, and surveillance in gastrointestinal cancers. While screening endoscopy has been the standard for diagnosing most gastrointestinal tumors, noninvasive CT colonography has evolved and is beginning to find routine use in practice. For diagnosis and staging, the CT scan has been the backbone of imaging over the last 30 years. Functional imaging modalities, such as PET scans, are now employed as an added tool to assist in the diagnosis and staging of GI cancers, particularly to detect occult metastatic disease so futile surgical interventions can be avoided. PET has been adopted for routine staging for esophageal cancers and data is evolving in other GI cancers. Clinical trials data using functional imaging for early treatment monitoring for GI cancers is limited. The best data is in esophageal cancer, where a multi-institutional study showed that PET done at 2 weeks after induction chemotherapy could be used to identify patients with metabolic response. Future clinical trials using functional imaging may enable clinicians to provide rapid adjustments to therapy for each patient. The role of surveillance in patients with resected cancer is to detect early recurrence, which is amenable to curative resections. Studies have shown that routine follow-up with CT, along with CEA and colonoscopy has shown to improve survival in colorectal cancer patients. Ultimately, the proper use of all available imaging technology will translate to improved clinical outcomes in GI cancer patients. © 2011 Springer-Verlag Berlin Heidelberg.