Résumé : Brain metastases are a major problem in the management of small cell lung cancer (SCLC) with an incidence rising to 50% at 2 years. Prophylactic cranial irradiation (PCI) has shown through randomized trials and meta-analysis to decrease the incidence of brain metastases by 25% leading to a 5% survival benefit at 3 years for patients in complete response to the initial therapy. The major concern with PCI is the risk of inducing neurologic symptoms, especially cognitive functions, and an impaired quality of life. In extensive disease SCLC, an active surveillance with magnetic resonance imaging (MRI) has questioned the value of routine PCI challenging its use for limited disease. In this paper, we will review some main limitations of the different randomized trials, the impact of new technologies and the data available on the possibility to omit (or not) PCI for limited disease.