Phase II study of concomitant radiotherapy with atezolizumab in oligometastatic soft tissue sarcomas: STEREOSARC trial protocol oleh Nicolas Penel, Dominique Vaur, Juliette Thariat, Alexandre Escande, Jennifer le Guevelou, Colin Debaigt, Esma Saada-Bouzid, Julien Viotti, Nazim Khalladi, David Thibouw, Marie Pierre Sunyach, Laurence Moureau-Zabotto, Mohamed Benchalal, Ovidiu Veresezan, Anne Ducassou, Cecile le Pechoux, Maria Jolnerovski, Celine Bazille, Raphael Serre, Christine Lovera