1. Oncology Hematology Dept, Hellenic Airforce General Hospital, Athens, Greece;
2. Pain Relief and Palliative Care Unit, Department of Radiology, Areteion Hospital, School of Medicine, National & Kapodistrian University of Athens, Athens, Greece;
3. Nursing Department, National & Kapodistrian University of Athens, Athens, Greece;
4. Anaesthesiology, Attikon University Hospital, Attiki, Greece