1. Radiation Oncology Unit, Department of Biomedical, Dental and Morphological and Functional Imaging Sciences, University of Messina, 98122 Messina, Italy
2. Radiology I Unit, Department of Medical Surgical Sciences and Advanced Technologies “G.F. Ingrassia”, University of Catania, 95123 Catania, Italy
3. Radiation Oncology Unit, Department of Medical Surgical Sciences and Advanced Technologies “G.F. Ingrassia”, University of Catania, 95123 Catania, Italy
4. Radiotherapy Unit, A.O.E. Cannizzaro, 95126 Catania, Italy
5. Radiotherapy Unit, ARNAS Civico Hospital, 90127 Palermo, Italy