Alves, Francisco José Cerqueira, 1970-Costa, Ana Patrícia Parreira Leitão Gomes da2020-02-142020-02-1420142014-10http://hdl.handle.net/10400.26/31402Radiation therapy planning has traditionally relied very heavily on CT imaging. However, Fluorodeoxyglucose Positron Emission Tomography (FDG PET), more specifically PET fused with Computed Tomography (PET/CT), is emerging as the standard of care for the staging, monitoring of response to therapy and detection of disease recurrence, for numerous malignancies. So that more and more radiation oncologists believe that target volume selection and delineation cannot be adequately performed without the use of PET/CT. In order to perform high quality examinations, PET/CT imaging protocols used for radiation therapy planning must be rigorous and consistently applied, which is the technician’s responsibility. However, when adapting the scanners for these examinations many difficulties appear, since the patient is immobilized and the use of FDG as a radiotracer may not be the appropriate choice for the study of some malignancies. But, there is a promising future for PET/CT in treatment planning, with the development of radionuclides and biomarkers and of new treatment paradigms. This dissertation is written for technicians and from a technician’s point of view, covering the basis of Radiotherapy and Nuclear Medicine and addressing various aspects regarding PET/CT examinations for radiotherapy planning. Exploring the challenges the professionals face during these examinations, this dissertation provides a solid foundation for those who want to learn more about this newly-discovered side of Nuclear Medicine and reflect about what needs to be changed in order for it to become the technique of choice for radiation treatment planning.engRadioterapiaRadiotherapyTomografia por emissão de positrõesPositron-Emission TomographyTomografia computorizadaComputed tomographymaster thesis201493071