Dual-tracer scintigraphy and subtraction studies in the diagnosis of hepatocellular carcinoma

Pancreatic and hepatobiliary cancers

Morphology-based imaging modalities have replaced classical conventional nuclear medicine modalities for detection of liver or pancreatic lesions. With positron emission tomography and the glucose analog F-18 fluorodeoxyglucose (FDG), a sensitive and specific modality for the detection of hepatic metastases and extrahepatic tumor deposits from hepatocellular or pancreatic cancer is available. F-18 FDG PET can increase the accuracy of staging primary tumors of the liver or the pancreas, and can be used for response monitoring. Radiopharmaceuticals such as Ga-68 DOTATOC and F-18 DOPA allow the specific detection of neuroendocrine pancreatic tumors and their metastatic deposits. Hybrid scanners such as PET-CT integrate morphologic and metabolic information, and allow to increase the sensitivity and specificity of noninvasive imaging in many tumor entities. The development of specific radiopharmaceuticals and technical innovations such as SPECT-CT has increased the reliability of conventional scintigraphic imaging. This chapter focuses on the use of PET-CT in hepatobiliary and pancreatic cancers.

Nuklearmedizinische Diagnostik von Lebertumoren

Standard nuclear medical procedures, such as functional, blood-pool and colloid scintigraphy, play a minor role in the routine workup of liver tumors. However, these techniques are capable of assessing specific organ functions and frequently allow the diagnosis of unclear liver lesions. The sensitivity of scintigraphic procedures can be increased using tomographic imaging (SPECT), the specificity with the introduction of hybrid scanners such as SPECT/CT. Whole body positron emission tomography with 18F-fluoro-deoxy-glucose (FDG) in combination with CT scanning (PET/CT) represents one of the most sensitive imaging modalities for the detection of hepatic metastases and extrahepatic tumor manifestations. For the staging and follow-up of colorectal cancer, FDG-PET/CT represents a standard imaging modality. Metastases from neuroendocrine tumors can be detected using PET and specific tracers such as [68Ga]DOTATOC and [18F]DOPA. Molecular imaging with PET allows the quantification of metabolic processes which can be used for the assessment of an early response to treatment.