1. Department of Radiation Oncology, ASL TO4, Ivrea Community Hospital, Ivrea
2. Department of Medical Physics, ASL TO4, Ivrea Community Hospital, Ivrea
3. Radiation Oncology Department, Tomotherapy Unit, “U Parini” Regional Hospital, AUSL Valle d'Aosta, Aosta
4. Department of Medical and Surgical Sciences, Radiation Oncology Unit, University of Turin, S Giovanni Battista Hospital, Turin, Italy