1. Department of Surgery, Kantonsspital St. Gallen, 9007 St. Gallen, Switzerland
2. Department of Visceral and Transplant Surgery, University Hospital Zurich, 8091 Zurich, Switzerland
3. Department of Radiation Oncology, Kantonsspital St. Gallen, 9007 St. Gallen, Switzerland
4. Department of Radiation Oncology, Inselspital, University of Bern, 3010 Bern, Switzerland