The Radiation Target in Small Cell Lung

The historic target for treating small cell lung cancer with curative radiation was simply defined by what could be “safely” encompassed within a single (hemi-thoracic) “portal” drawn on a chest X-ray film. Six decades of advances in radiologic and nuclear medicine imaging have led to a revision of this classically defined target to one that more accurately reflects the true extent of actual disease. Accuracy in target definition has been matched to advances in technology for radiotherapy (RT) planning and delivery so that current treatment approaches are more likely to result in optimal cancer control while minimizing normal tissue irradiation and treatment-related side effects. This chapter will review historic trials and ongoing studies to provide a comprehensive understanding on the evolution of the RT target in small cell lung cancer.