1. Division of Radiology and Nuclear Medicine, Kantonsspital St. Gallen, St. Gallen, Switzerland
2. Faculty of Medicine, University of Zurich, Zurich, Switzerland
3. Clinical Trials Unit, Kantonsspital St. Gallen, St. Gallen, Switzerland
4. Department of Radiation Oncology, Kantonsspital St. Gallen, St. Gallen, Switzerland
5. Department of Radiation Oncology, University of Bern, Bern, Switzerland