ESTRO ACROP guidelines for target volume definition in the thoracic radiation treatment of small cell lung cancer

C. Le Péchoux, Corinne Faivre‐Finn, Sara Ramella, Fiona McDonald, Farkhad Manapov, Paul Martin Putora, Ben J. Slotman, Dirk De Ruysscher, Umberto Ricardi, Xavier Geets, J. Belderbos, Christoph Pöttgen, Rafal Dziadiuszko, Stéphanie Peeters, Yolande Lievens, Coen Hurkmans, Paul Van Houtte, Ursula Nestle