Purpose: The aim of this study is to investigate the role of standard uptake values (SUVs) and metabolic tumor volume (MTV) in [(18)F]fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) to predict the short-term outcome of chemoradiotherapy (CRT) in patients with advanced non-small cell lung cancer (NSCLC).
Methods: A total of 37 patients were included in the prospective study. All patients were evaluated by FDG PET before and following 40 Gy radiotherapy (RT) with a concurrent cisplatin-based chemotherapy regimen. Semiquantitative assessment was used to determine maximum and mean SUVs (SUV(max)/SUV(mean)) and metabolic tumor volume (MTV). Short-term outcome using the treatment response evaluation was assessed according to the Response Evaluation Criteria in Solid Tumors. The receiver-operating characteristic (ROC) curve analysis was used to determine the diagnostic accuracy of (18)F-FDG PET in identifying responders.
Results: Changes in SUV(max), SUV(mean), and MTV were significantly more pronounced in responders than in nonresponders (p = 0.002, 0.002, 0.000). The thresholds of SUV(max), SUV(mean), and MTV changes defined by ROC curve analysis were 37.2, 41.7, and 29.7%, respectively. The sensitivity, specificity, and accuracy of SUV(max) change for predicting tumor response were 83.3, 84.6, and 84.9%, respectively. The sensitivity, specificity, and accuracy of SUV(mean) change for predicting tumor response were 79.2, 100, and 88.8%, respectively. The sensitivity, specificity, and accuracy of MTV change for predicting tumor response were 91.7, 84.6, and 92.3%, respectively.
Conclusion: SUV and MTV changes from two serial (18)F-FDG PET/CT scans, before and after initial CRT, allow prediction of the treatment response in advanced NSCLC.