PET radiopharmaceuticals in oncology beyond FDG

Abstract

Several imaging modalities to diagnose cancer, which include computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, optical imaging, and gamma scintigraphy, have been previously used. For instance, CT and MRI provide considerable anatomic information about the location and the extent of tumors, but do not adequately differentiate residual or recurrent tumors from edema, radiation necrosis, or gliosis. On the other ultrasound images provide limited information about local and regional morphology with blood flow. Similarly optical imaging showed promising results, but did not demonstrate the ability to detect deep tissue penetration. Notably, radionuclide imaging modalities are diagnostic cross-sectional imaging techniques that map the location and concentration of radionuclide-labeled compounds. Moreover, molecular imaging agents are making it possible to “see” the molecular makeup of the tumor and its metabolic activity beyond tumor location, size, shape, and viability. Other technological limitations include nuclear images, which can provide a very accurate definition of metabolically active areas, but miss anatomic features. As a result, new imaging modalities have combined nuclear images with CT scans for treatment planning. The hybrid scanners combine anatomic and functional images taken during a single procedure, without having to reposition the patient between scans. In this chapter, multiple ligands beyond clinical standard 18F-fluorodexoyglucose are reviewed.