1. Service de Radiothérapie Oncologie, Centre Hospitalier Lyon-Sud, Université Claude Bernard, Pierre Benite cedex, France, and EA 3738
2. Bio-Images and Radiological Sciences Department, Radiotherapy Institute, Catholic University, Rome
3. Department of Medical and Surgical Sciences, Radiation Oncology Unit, University of Turin, Ospedale S. Giovanni Battista, Turin
4. Radiation Oncology Department, Azienda Ospedaliera “Civile-MP Arezzo”, Ragusa
5. Radiation Oncology Department, Ospedale Cardinale Ascalesi, Naples
6. Radiotherapy Unit, University of Florence, Florence, Italy