Diagnosis - Tomography with Emission of Positrons (PET)

PET is a diagnostic method of nuclear medicine that is based on the use of tracers marked with positron-emitting isotopes produced by compact cyclotrons for medical use. The PET study, together with the morph-anatomic studies (such as echographia, traditional X-ray, computerized tomography – TC – and magnetic resonance – RM -) makes it possible to metabolically characterize lesions identified or not, with traditional methods.

Therefore fundamental is the integration of functional PET images with anatomic TAC images, an integration intended not only for the simultaneous visualization and interpretation of the two studies, but also of their spatial alignment, for a more accurate identification of the anatomical structures.

During recent years, there has been an exponential development in method, especially in the oncological field. In all cases fasting for at least 6 to 8 hours is necessary. The tracer is administered intravenously and no collateral or undesired effects have been noted. The use of the PET with specific tracers that measure the cellular metabolism of the tumor makes it possible to evaluate the degree of aggressiveness of the tumor, the presence and distribution of the metastasis from a distance, the effect of chemo and/or radio-therapy on the vitality of the tumor and the differential diagnosis between the tumoural and necrosis relapse of the radiation therapy. In this way it is possible to obtain a more precise clinical picture and precise study by limiting the number of invasive diagnostic procedures. The required time depends on the type of tracer used: it is about 4 hours from the moment one is called to the moment when the examination is finished, when it is necessary to carry out a study with F-18 FDG.

After the administration of the F-18 FDG tracer, it is necessary to wait about 45-90 minutes while drinking a minimum of 2-3 glasses of water (available in the waiting room) in order to favor the elimination of the tracer that is not metabolized+ by the organism. Access criteria: TC and/or RM as an anatomical reference. It is important for the evaluation of the PET examination to bring with you and hand over to the professional nurse assigned to accept the patient together with the case history, not only the report of the TC and/or RM instrumental studies but also the X-rays, which are necessary for interpreting the images.