Stereotactic Body Radio Therapy (SBRT) for Early-stage Non Small Cell Lung Cancer (NSCLC)

The main objective of this study is to do a health economic evaluation of innovating techniques in radiotherapy. SBRT is the very precise delivery of high-powered radiation to small target volumes, using multiple low-intensity beams. Extremely precise patient positioning and target location is essential for accurate treatment delivery. Several studies have shown a benefit of SBRT in terms of local control and progression-free survival, in particular for the treatment of cerebral metastases of limited number and size. The development of this technique is recent. The number of treatment sessions is low: 1 to 4. But the patient is exposed to a major risk of toxicity in several organs: the bronchi, the lungs, large vessels, the oesophagus and the spinal-cord. Pulmonary SBRT imposes strict rules and the use of specific equipment. Extra-cranial SBRT can be realized using either: * Conventional linear-accelerator equipped SBRT, * Cyberknife SBRT. 3 groups of treatment will be evaluated in this study: * SBRT by cyberknife, * SBRT by linear accelerator, * Conformational radiotherapy (free breathing or breath holding).