1. Department of General and Upper Gastrointestinal Surgery, University of Verona , Verona , Italy
2. Unit of Epidemiology and Medical Statistics, Department of Diagnostics and Public Health, University of Verona , Verona , Italy
3. Department of Oncology, University of Verona , Verona , Italy
4. Department of Radiology, OCM Hospital of Verona , Verona , Italy
5. Gastroenterology and Digestive Endoscopy Unit, University of Verona , Verona , Italy
6. Department of Radiation Oncology, University of Verona , Verona , Italy