Characterisation and classification of oligometastatic disease: a European Society for Radiotherapy and Oncology and European Organisation for Research and Treatment of Cancer consensus recommendation

Matthias Gückenberger, Yolande Lievens, Angelique B. Bouma, Laurence Collette, André Dekker, Nandita M. deSouza, Anne‐Marie C. Dingemans, Béatrice Fournier, Coen Hurkmans, Frédéric Lecouvet, Icro Meattini, Alejandra Romero, Umberto Ricardi, Nicola S. Russell, Daniel H. Schanne, Marta Scorsetti, Bertrand Tombal, Dirk Verellen, Christine Verfaillie, Piet Ost