[The role of positron emission tomography (PET) in tumor diagnostics and therapy monitoring].

Abstract

Positron emission tomography (PET) is a medical imaging method belonging to the realm of nuclear medicine. It has been a clinical research tool since the sixties but during the late nineties it became widely utilized in clinical practice too. PET technique requires special radioactive isotopes, which may be generated only in particle accelerators (cyclotrons) and their transport is limited owing to the short physical half-life. PET/CT was born from the combination of PET and CT (computer tomography). The first combined PET/CT scanner began to operate in 1998 and the method has been used in clinical practice since 2001. It is a hybrid (multi-modality) medical imaging equipment which can provide anatomical, morphologic (CT) and functional, metabolic information (PET) simultaneously. PET/CT imaging has gained clinical acceptance mainly in oncology - owing to the attributes of the most frequently used PET tracer, fluoro-deoxy glucose (FDG) - and in a lesser extent in neuropsychiatry and cardiology. The authors in this paper review the basics and key indications of the method, the wider used radiofarmacons, including potential neurological and psychiatric applications, and the possible causes of false positivity and false negativity.