The staging classification for SCLC is the 2-stage Veterans Administration Lung Study Group system that categorizes patients as having limited or extensive disease. Limited stage SCLC is disease confined to 1 hemithorax with or without adjacent mediastinal and/or supraclavicular lymph node involvement, but without a pleural effusion. This extent of disease can be included in a tolerable radiation field. Extensive-disease SCLC is any disease beyond the definition of limited-stage disease.