Irradiation of Large Lung Tumors or Two or More Lung Metastases Simultaneously

Inclusion Criteria for group A and B: * Weight loss \< 10% in the last three months. * WHO-performance status ≤ 2 * Medical inoperable patients or patients refusing surgery. * Chemotherapy is allowed in neoadjuvant and adjuvant setting, with exclusion of the period 4 weeks pre-SBRT and 6 weeks post-SBRT. * Before patient registration, written informed consent must be given according to ICH/GCP, national and local regulations. Risk group A specification: * NSCLC (Cytological or histological proven) patients with peripheral tumors \>5 cm with tumor staging cT2bN0M0 or cT3N0M0 (chest wall infiltration is no exclusion criteria, as long as the tumor diameter is \> 5 cm). * Single peripheral lung metastasis in inoperable patients with a diameter of \> 5 cm. In case of first presentation of metastatic disease, cytological or histological proof is obligated. * In patients without cytological or histological confirmation of NSCLC, a growing FDG-PET positive lesion (SUV \>5) is accepted if a contra-indication for invasive diagnostic examination (or refusal) is present. Risk group B specification: * Patients with ≥ 2 simultaneous peripheral lung metastases ≤ 5 cm of any origin at any location in the lung. * In case of first presentation of metastatic disease, cytological or histological proof is obligated. This is not necessary in case of a history of an already proven disseminated disease. * Patients having ≥ 2 peripheral lung metastases without unacceptable dose overlap. Exclusion Criteria: * Patients with central tumors * Pancoast tumors * Prior radiotherapy treatment to the thorax * Patients receiving any systemic treatment during SBRT * Pregnant patients * Patients previously treated with adriamycin agents in case of heart involvement within the treatment field.