Table 1 Inclusion and Exclusion Criteria.

Histologically-proven NSCLC

Involvement of supraclavicular lymph nodes

Tumor stage III A – C according to the UICC TNM classification (8th edition)

Additional pulmonary lesion (in the same or another lobe)

Indication for definitive thoracic CRT

Previous thoracic RT, if previous and current target volumes overlap

Age ≥ 18 years

Patients who have not yet recovered from acute toxicities of prior therapies

ECOG Score 0–2 (KPI ≥ 70%)

Contraindications against MRI scans

Adequate pulmonary function for CRT

Ability to lie still on the MR-linac table ≥ 1 h

Ability to hold one’s breath > 20 s

Successful completion of MR-guided RT simulation on the treatment machine