Increased Relapse Rates in Early Stage Hodgkin Lymphoma (HL) Patients without Radiotherapy: The German Society of Radiooncology (DEGRO) Advises to Treat all Early Stage HL Patients with Radiotherapy - Körholz, D.; Mauz-Körholz, C.; Vordermark, D.; Kluge, R.; Dieckmann, K. (Klinische Pädiatrie, 2014)