Integrated Imaging in Gastrointestinal Oncology: PET/CT Imaging
The basic principle of positron emission tomography (PET) is the use of positron-emitting-isotope-labeled pharmaceuticals that are integrated into a metabolic pathway. Positron-emitting isotopes are characterized by a beta plus-decay, in which a positron is emitted. This positron collides with and annihilates any of the many shell electrons in the neighboring atoms, thereby producing two 511-keV gamma rays (photons) which are detected in coincidence by the PET scanner. The additional integration of a computed tomography scanner (PET/CT) allows the acquisition of PET and CT images of the patient in the same imaging session. The clinically and most widely evaluated positron-emitting isotope labeled pharmaceutical is fluorine-18 fluoro-2-deoxy-D-glucose (FDG). This glucose analogue is transported into the cell by specific transporters and phosphorylated by hexokinase to FDG-6-phosphate. As FDG-6-phosphate is inert to further metabolic processing or to transmembrane back-transport outside the cell, it accumulates within the cells. The physical half-life of FDG is around 110 min.
KeywordsPositron Emission Tomography Positron Emission Tomography Imaging Gastrointestinal Stromal Tumor Gallbladder Cancer Integrate Image
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- 18.Zervos EE, Badgwell BD, Burak WE Jr et al (2001) Fluorodeoxyglucose positron emission tomography as an adjunct to carcinoembryonic antigen in the management of patients with presumed recurrent colorectal cancer and nondiagnostic radiologic workup. Surgery 130:636–643; discussion 643–644CrossRefPubMedGoogle Scholar
- 19.Goldberg RM, Fleming TR, Tangen CM et al (1998) Surgery for recurrent colon cancer: strategies for identifying resectable recurrence and success rates after resection. Eastern Cooperative Oncology Group, the North Central Cancer Treatment Group, and the Southwest Oncology Group. Ann Intern Med 129:27–35PubMedGoogle Scholar
- 25.Goerres GW, Stupp R, Barghouth G et al (2004) The value of PET, CT and in-line PET/CT in patients with gastrointestinal stromal tumours: long-term outcome of treatment with imatinib mesylate. Comparison of PET, CT, and dual-modality PET/CT imaging for monitoring of imatinib (STI571) therapy in patients with gastrointestinal stromal tumors. Eur J Nucl Med Mol Imaging 4:4Google Scholar