[PET-CT scan: a major progress toward fused, metabolic and functional images]

Positron emission tomography (PET) is an imaging method that allows metabolic mapping of disease processes after a specific radiotracer administration. One of the major disadvantages of using radioactive glucose is the fact that this radiotracer is not entirely specific for tumor tissue. Also, the physiological distribution of 18F FDG makes difficult the anatomical localization. Computed tomography (CT) provides en excellent anatomic resolution but the functional information is reduced. In this circumstances PET and CT gives complementary information, and together increase the lesions localization and reduce the artifacts of interpretation. That was exactly the purpose for building the new hybrid gamma camera PET-CT. The new concept of hardware fusion between PET and CT is now commercially available from five years. By the meaning of fused anatomic and functional imaging PET-CT has already found a number of clinical applications in oncology. The new imaging technology reduces image acquisition time, improves tumor localization which is difficult if not impossible with PET alone, and calculate more accurate the target tumor volume for radiotherapy planning. This article is a review from literature data, concerning the mean indications, weaknesses, current evidence and future directions of PET-CT. In Romania, there are not available either PET or PET-CT. We believe that the aspiration at the European standards will remedy it as soon as possible.