Pet CT is a hybrid imaging method formed with the integration of PET (Tomography Positron Emitting Devices) and CT (Computer Tomography) devices, during this procedure radioactive substances are used in order to find the tumor or the metastasis which enable the release of metabolic and anatomical information of the body organs. This device is used to detect tumors, determine the extent of tumors and metastasis proliferation, radiotherapy planning, evaluating the response to treatment, and in some cases to determine if the mass is benign or malignant.