The reasons for incomplete application of the different treatment modalities (percentages of patients: see Table 1) were: fever and adverse gastrointestinal effects (IFN‐β application incomplete, n = 1), systemic progression under RCT (radiotherapy and concomitant chemotherapy incomplete, n = 1), by patient request due to grade 1 mucositis (radiotherapy incomplete, n = 1), and acute kidney injury (chemotherapy incomplete, n = 1). Here, IFNB1 is linked to mucositis.