The majority of patients with limited disease small cell lung cancer (SCLC) experience recurrent disease despite receiving concurrent chemoradiotherapy. New agents and dose-escalation of chemotherapy have not provided a survival benefit. Local failure accounts for high proportion of recurrences. Improved thoracic radiotherapy (TRT) might increase local control and thus reduce the recurrence rate and prolong survival. Positron emission tomography (PET CT) is better for staging of SCLC than computer tomography (CT) and bone scan. More precise localization of tumors leads to more accurate definition of target volumes for TRT and reduce the radiation dose to normal tissue. A large proportion of patients relapse and die within one and two year after therapy. Few patients survive longer than three years. Thus, two-year survival is considered a clinically highly relevant measure of efficacy.