The Role of Nuclear Imaging in Gastrointestinal Disorders: GI Cancers

Steven Marks

^*President, MedCom Consultants, Inc, Potomac, Maryland

Address correspondence to: Steven Marks, MedCom Consultants Inc, 1311 Fallsmead Way, Potomac, Maryland, 20854. E-mail: steven.marks52@gmail.com.

Disclosure statement: Steven Marks reports having no financial or advisory relationship with any corporate, medical, or political organization doing work related to this paper or other business activity at MedCom Consultants, Inc.

ABSTRACT

Leading causes of morbidity and mortality around the world, gastrointestinal (GI) cancers are a growing economic and health burden on society. These malignancies, including cancers of the stomach, esophagus, pancreas, liver, colon, and rectum, as well as GI stromal and gastroenteropancreatic neuroendocrinal tumors, account for more than one-quarter of all newly diagnosed cases and one-third of all deaths annually. Functional nuclear imaging, including positron emission tomography (PET) and related hybrid modes, particularly PET/computed tomography (CT), have made a notable contribution to the visualization of many cancer types. Using the most common radiopharmaceutical 2-[¹⁸F] fluoro-2-deoxy-D-glucose (FDG), PET/CT, which can capture both metabolic and anatomic imaging data with a single device in a single imaging session, has offered improved diagnostic accuracy while enhancing treatment planning and response assessment, disease staging and prognosis, and overall patient management. The advent of new radiotracers and novel approaches, including dual-tracer PET/CT, dynamic blood flow and dual-phase PET imaging, has offered the possibility of visualizing other metabolic processes than glucose metabolism, many of which offer increased diagnostic accuracy. They have been the focus of much current research. However, the absence of standardized response-assessment criteria for the use of PET/CT in patients with GI cancers remains a critical gap hindering the more widespread use of nuclear imaging in many community clinical settings.

This course will examine the role of nuclear imaging in GI cancers; it will contain a thorough discussion of a number of the central malignancies, including gastric, pancreatic, esophageal, and CRCs, hepatocellular carcinoma, and GI stromal and neuroendocrinal tumors. Here, the emphasis will be on PET and PET/hybrid techniques, as well as, when apposite, scintigraphy, and will explore imaging's contribution to the diagnosis, staging, the assessment of treatment response, and monitoring of disease recurrence. In all cases, the place of established and investigational radionuclides in the imaging armamentarium will be described as well. Finally, a number of patient case studies will conclude this course, offering practical and real-world illustrations of how nuclear imaging can contribute to the clinical management of patients presenting with symptoms suggestive of underlying GI cancer.