FLT-PET has been studied in SCLC xenografts in mice showing promise for early response evaluation of treatment with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR TKI) (Pardo et al. 2009), but we are unaware of any studies of FLT-PET in patients with SCLC. This evidence concerns the gene EGFR and small cell lung carcinoma.