1. Radiation Oncology Unit, 1st Department of Radiology, School of Medicine, Aretaieion Hospital, National and Kapodistrian University of Athens (NKUOA), 11528 Athens, Greece
2. Department of Radiotherapy/Oncology, Medical School, Democritus University of Thrace, 68100 Alexandroupolis, Greece
3. Department of Pathology, Aretaieion University Hospital, School of Medicine, National and Kapodistrian University of Athens, 11528 Athens, Greece
4. Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
5. Radiotherapy Unit, 2nd Department of Radiology, Attikon Hospital, School of Medicine, Rimini 1, National and Kapodistrian University of Athens, 12462 Athens, Greece