1. Department of General, Endocrine and Transplant Surgery, Medical University of Gdansk, Gdansk, Poland;
2. Department of General, Transplant and Liver Surgery, Medical University of Warsaw, Warsaw, Poland;
3. Department of Radiotherapy, European Institute of Oncology, Milan, Italy;
4. Danish Center for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark;
5. Department of Oncology and Hemato-Oncology, University of Milan, Milan, Italy;
6. Division of Radiotherapy, IEO European Institute of Oncology, IRCCS, Milan, Italy