During the past three decades, treatment progress in small cell lung cancer (SCLC) has been modest and mainly achieved in patients staged as having limited disease (LD-SCLC) by the addition and refining of locoregional radiation to systemic chemotherapy. Three landmarks have been accomplished: (1) the addition of thoracic radiation therapy to systemic chemotherapy; (2) the demonstration of the superiority of early and/or twice-daily radiation therapy compared with late, once-daily fractionation; and (3) prophylactic radiation therapy of the brain, the so-called prophylactic cranial irradiation (PCI). Each of these innovations has contributed to an improvement of the 5-year survival rate in LD-SCLC. In contrast, progress in the treatment of patients with extensive disease (ED-SCLC) has been very modest. However, recently a significant step towards further improvement of palliative treatment has emerged with the demonstration that PCI also plays a definite role in the treatment of extensive disease.1