Early Prediction of Nonprogression in Advanced Non–Small-Cell Lung Cancer Treated With Erlotinib By Using [18F]Fluorodeoxyglucose and [18F]Fluorothymidine Positron Emission Tomography

Purpose Positron emission tomography (PET) with both 2′-deoxy-2′-[18F]fluoro-d-glucose (FDG) and 3′-[18F]fluoro-3′-deoxy-l-thymidine (FLT) was evaluated with respect to the accuracy of early prediction of nonprogression following erlotinib therapy, independent from epidermal growth factor receptor (EGFR) mutational status, in patients with previously untreated advanced non–small-cell lung cancer (NSCLC). Patients and Methods Thirty-four patients with untreated stage IV NSCLC were evaluated in this phase II trial. Changes in FDG and FLT uptake after 1 (early) and 6 (late) weeks of erlotinib treatment were compared with nonprogression measured by computed tomography after 6 weeks of treatment, progression-free survival (PFS), and overall survival (OS). Results Changes in FDG uptake after 1 week of therapy predicted nonprogression after 6 weeks of therapy with an area under the receiver operating characteristic curve of 0.75 (P = .02). Furthermore, patients with an early metabolic FDG response (cutoff value:...