Calculation of an analytical memory for the installation of a PET-CT equipment in the Nuclear Medicine Department of the National Institute of Cancerology

The studies with a PET-CT equipment combines the metabolic information that provides the Positron Emission Tomography technique (PET), with the morphological data offered by the Computerized Tomography (CT). In Mexico, it will have the first PET-CT equipment, for a public service hospital. Since that makes use of radioactive material (emission of annihilation photons with 511 keV) and X rays, is necessary to calculate the necessary shielding for the PET-CT equipment room and for the area where it is managed or have presence of radioactive material (mainly fluorodeoxyglucose labelled with F-18, i.e. FDG-F18). It is presented a summary of the calculations and necessary considerations so that the shielding allows to fulfill with the official doses limits in Mexico (50 mSv/year for Occupationally Exposure Personnel, OEP and 5 mSv/year for public in general), taking into account the adjacent areas to the installation. It is concluded with the shielding thickness required for the walls and roof of the installation, having a maximum of 20 cm of concrete (ρ = 2.35 g/cm3) for the administration room of radioactive material to the patients and a minimum of 1 mm of lead for the room of the PET-CT equipment, having taken into account the dimensions of each area. (Author)