Insufficient migration and activation of tumour specific effector T cells seems to be the one important reason for inadequate host anti-tumour immune response. Ionizing radiation can induce a variety of immune responses. The goal of this randomized trial is to assess if a preoperative single fraction low dose radiation is able to improve anti-tumour immune response in operable early stage lung cancer.

Inclusion Criteria:

• Histologically proven clinical stage I to IIA pulmonary adenocarcinoma
• Lung tumor is felt to be curatively resectable by the treating physicians
• Sufficient pulmonary function for lobectomy according to current guidelines
• The patient is free of distant metastases as confirmed by contrast-enhanced chest and upper abdomen CT-scan and by contrast-enhanced CT or MRI of the brain
• Age over 50years at the time of consent due to federal radiation protection law
• In female patients of childbearing potential there must be a negative pregnancy test
• Eastern Cooperative Oncology Group performance status of 0,1, 2 or 3 at the time of randomization
• Patients who the investigator believes can and will comply with the requirements of this protocol
• Written informed consent according to good clinical practise and national/regional regulations

Exclusion Criteria:

• The patient shows clinical signs of pneumonia
• The patient receives immunosuppressive drugs (alkylating agents, antimetabolites, methotrexate, azathioprine, mercaptopurine, cytotoxic antibodies, ciclosporin, tacrolimus, sirolimus, interferon, mycophenolate, small biological agents)
• The patient has been diagnosed with a potential immune mediated disease
• Elevated blood leukocyte count or erythrocyte sedimentation rate
• Pregnancy
• The patient has received any cancer specific treatment, including radiotherapy, immunotherapy, hormonal therapy or chemotherapy
• The patient is diagnosed with a concomitant malignancy and/or has a history of malignancy within the past five years or has had a malignancy that has been in complete remission for less than 5 years
• The patient needs chronic long term oxygen therapy
• The patient has undergone splenectomy
• The patient is known to be HIV positive
• The patient has an uncontrolled bleeding disorder