Jose Fernando Pérez Azorín1, Luis Isaac Ramos García2, Josep M Martí-Climent3. 1. Department of Medical Physics, Hospital Universitario de Cruces, Plz. Cruces s/n, Barakaldo, Bizkaia 48903, Spain josefernando.perezazorin@osakidetza.net. 2. Department of Oncology, Clínica Universitaria de Navarra, University of Navarre, Av. Pio XII s/n, Pamplona, 31008, Navarre, Spain liramos@unav.es. 3. Department of Nuclear Medicine, Clínica Universitaria de Navarra, University of Navarre, Av. Pio XII s/n, Pamplona, 31008, Navarre, Spain jmmartic@unav.es.