Patients in this trial undergo primary radiochemotherapy for locally advanced NSCLC. As early and intermediate late effects of radiotherapy do not only hamper quality of life but can, in the case of radiation induced pneumonitis, be potentially lethal, a reduction of these side effects is desirable. Patients in this trial are 1:1 randomised to intensity modulated radiotherapy with photons or proton therapy. The primary aim of the study is to show a decrease of pneumonitis and or esophagitis grade 2 or higher by proton therapy. The observed incidence of both these side effects is 39% with photon therapy. The estimated incidence with proton therapy is around 12 %. Simultaneous chemotherapy will be applied to current clinical standards.