1. Thoracic Surgery Department, Attikon University Hospital of Athens, Greece
2. 2nd Radiology Department, Attikon University Hospital of Athens, Greece
3. 4th Department of Internal Medicine, Attikon University Hospital of Athens, Greece
4. 2nd Department of Anesthesiology, Attikon University Hospital of Athens, Greece
5. Department of Epidemiological Surveillance and Intervention, Hellenic Centre for Disease Control and Prevention, University of Athens, Greece