Patients with locally advanced non-small cell lung cancer are threatened by the concurrent risks of local, regional and distant failure. By improving local and regional control with multimodality protocols, the brain becomes one of the major sites of relapse. PCI has a high potential to reduce the risk of brain metastases. Long-term toxicity is presently poorly defined and represents an important potential risk. The value of PCI as an adduct to present aggressive multimodality protocols and the optimal total dose with conventional fractionation will be investigated within clinical studies by two study groups in the future. As the best dose and fractionation still remains undefined, the integration of PCI into multimodality protocols.