Inclusion criteria (let op korte versie, zie full protocol voor details)

• Male or female, aged 18 years or above
• Scheduled to receive one of the following two therapeutic strategies:
  Concurrent chemotherapy and radiotherapy with photons (60 Gy in 30 fractions of 2 Gy) in patients with stage III NSCLC
  Concurrent chemotherapy and radiotherapy with protons (60 Gy in 30 fractions of 2 Gy) in patients with stage III NSCLC

Exclusion criteria

• Mixed non-small cell lung cancer with other histologies such as small cell lung cancer
• Not able to comply with the study protocol
• Previous radiotherapy to the chest for benign or malignant conditions, including radiation for breast cancer
• Previous malignancy treated with chemotherapy, immune therapy or radiotherapy (irrespective of when this happened)
• Previous malignancies treated with surgery only are allowed if 2 years or more before inclusion in the present study