Relevance of positron emission tomography (PET) in oncology

Background: The clinical use of positron emission tomography (PET) for dete ction and staging of malignant tumors is rapidly increasing. Furthermore, e ncouraging results for monitoring the effects of radio- and chemotherapy ha ve been reported. Methods: This review describes the technical principles of PET and the biol ogical characteristics of tracers used in oncological research and patient studies. The results of clinical studies published in peer reviewed journal s during the last 5 years are summarized and clinical indications for PET s cans in various tumor types are discussed. Results and Conclusions: Numerous studies have documented the high diagnost ic accuracy of PET studies using the glucose analogue F-18-fluordeoxyglucos e (FDG-PET) for detection and staging of malignant tumors. In this field, F DG-PET has been particularly successful in lung cancer, colorectal cancer, malignant lymphoma and melanoma. Furthermore, FDG-PET has often proven to b e superior to morphological imaging techniques for differentiation of tumor recurrence from scar tissue. Due to the high glucose utilization of normal gray matter radiolabeled amino-acids like C-ll-methionine are superior to FDG for detection and delineation of brain tumors by PET. In the future, mo re specific markers of tumor cell proliferation and gene expression may all ow the application of PET not only for diagnostic imaging also but for non- invasive biological characterization of malignant tumors and early monitori ng of therapeutic interventions.