Thirteen percent of all newly diagnosed lung cancer patients are diagnosed with small-cell lung cancer (SCLC). Of these patients with SCLC, approximately 39 percent are diagnosed with limited-stage disease, i.e. 
only present in one lung, but which may have spread to lymph nodes or tissue between the lungs. Such patients are often treated with chemotherapy and definitive radiation therapy. Staging information is essential because of the high propensity for metastatic disease in SCLC. The identification of metastases can spare patients from the toxicity associated with thoracic radiotherapy. Furthermore, in those patients who do receive radiotherapy, knowing the exact extent of disease may permit more accurate treatment volume delineation.
Until 2011, the United States National Comprehensive Cancer Network (NCCN) recommended a bone scan as part of the initial evaluation of all newly diagnosed SCLC patients. However, in 2012, the NCCN began recommending positron emission tomography computed tomography (PET-CT) in lieu of bone scan. Researchers (led by Dr Eric Xanthopoulos) from the University of Pennsylvania studied the clinical impact of using PET-CT instead and published their findings in the July issue of the Journal of Thoracic Oncology (JTO). The researchers concluded that PET-CT improves staging accuracy and intrathoracic disease identification, which translates into an improvement in clinical outcome in these patients. “Pretreatment PET staging of LS-SCLC was associated with improved survival,” the authors reported. “PET-staged patients had an improved 3-year overall survival from diagnosis (47 percent versus 19 percent; p-.03) compared with those with LS-SCLC who were not staged with PET.”