Standard uptake value and metabolic tumor volume of 18F-FDG PET/CT predict short-term outcome early in the course of chemoradiotherapy in advanced non-small cell lung cancer

Abstract

The aim of this study is to investigate the role of standard uptake values (SUVs) and metabolic tumor volume (MTV) in [¹⁸F]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). 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 ¹⁸F-FDG PET in identifying responders. 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. SUV and MTV changes from two serial ¹⁸F-FDG PET/CT scans, before and after initial CRT, allow prediction of the treatment response in advanced NSCLC.