A case of positive 68 Ga-DOTATOC-PET/CT pancreatic heterotopia mimicking an intestinal neuroendocrine tumor

PET/CT Variants and Pitfalls in Liver, Biliary Tract, Gallbladder and Pancreas

A wide variety of pathological anomalies may occur in the liver, biliary system, and pancreas. It is a necessity to use many different imaging techniques in order to distinguish such varied pathologies, especially those from malignant processes. Positron Emission Tomography/Computed Tomography (PET/CT) is an imaging method that has proven its diagnostic value in oncology and can be used for different clinical purposes. Fluoro-18 fluoro-2-deoxy-D-glucose has a wide range of uses as a dominant radiopharmaceutical in routine molecular imaging, however, molecular imaging has started to play a more important role in personalized cancer treatment in recent years with new Fluoro-18 and Gallium-68 labeled tracers. Although molecular imaging has a strong diagnostic effect, the surprises and pitfalls of molecular imaging can lead us to unexpected and misleading results. Prior to PET/CT analysis and reporting, information about possible technical and physiological pitfalls, normal histological features of tissues, inflammatory pathologies, specific clinical features of the case, treatment-related complications and past treatments should be evaluated in advance to avoid misinterpretation. In this review, the physiological and pathophysiological variants as well as pitfalls encountered in PET/CT imaging of the liver, biliary tract, gallbladder, and pancreas will be examined. Other benign and malignant pathologies that have been reported to date and that have led to incorrect evaluation will be listed. It is expected that the devices, software, and artificial intelligence applications that will be developed in the near future will enable much more effective and faster imaging that will reduce the potential causes of error. However, as a result of the dynamic and evolving structure of the information obtained by molecular imaging, the inclusion of the newly developed radiopharmaceuticals in routine practice will continue to carry new potentials as well as new troubles. Although molecular imaging will be the flagship of diagnostic oncology in the 21st century, the correct analysis and interpretation by the physician will continue to form the basis of achieving optimal performance.

Variants and Pitfalls of PET/CT in Neuroendocrine Tumors

Management of patients with neuroendocrine neoplasms (NEN) is complex and warrants referral of these patients to high volume centers with appropriate expertise to ensure favorable outcomes. PET/CT becomes increasingly important in every step of their management and outcome. The choice of radiopharmaceutical heavily depends on tumor origin, which is intimately interconnected to embryology, grade and clinical presentation (eg, diagnostic vs theranostic settings). The aim of this review is to describe the role of SSTR, ¹⁸F-FDOPA, and ¹⁸F-FDG-PET imaging in the evaluation of NEN patients. There is emphasis on the main variants, caveats, and pitfalls that can be observed within these modalities. Nuclear physicians must be equipped with the skills to handle potential variants, caveats, and pitfalls that are commonly encountered in NEN imaging, and they should understand the expected imaging features that are encountered across various types of NENs.