1. Department of Radiation Oncology, Centre Antoine Lacassagne, Côte d'Azur University, Nice, France;
2. Centre de Radiothérapie de Macon, Macon, France;
3. Centre Antoine Lacassagne, Nice, France;
4. Lucien Neuwirth Cancer Institute, Saint-Priest-En-Jarez, France;
5. Centre Léon Bérard, Lyon, France;
6. Institut Sainte-Catherine, Avignon, France;
7. Centre Hospitalier Lyon Sud, Pierre Benite, France;
8. Department of Radiation Oncology, Geneva University Hospital, Geneva, Switzerland;
9. Castle Hill Hospital, Cottingham, United Kingdom;
10. Clatterbridge Cancer Centre, Merseyside, United Kingdom;