The Predictive Value of Pretreatment 18-F-FDG-PET-CT in Locally Advanced Nasopharyngeal Cancer Patients Treated Definitively with Induction Chemotherapy Followed by Concurrent Chemo-Radiotherapy

Abstract

Background: This study aimed to evaluate the role of pretreatment [18F] fluorodeoxyglucose positron emission tomography (18F-FDG-PET) as a predictor of disease-free survival (DFS), and overall survival (OS) in locally advanced nasopharyngeal carcinoma (LANC) patients treated definitively with docetaxel-based induction chemotherapy followed by concurrent chemoradiation (CRT). Methods: After obtaining the institutional review board approval, we conducted a retrospective analysis of LANC patients (T1,N1-3 and T2-T4,anyN disease) treated definitively between January 2007 and December 2011 with induction chemotherapy docetaxel , cisplatin, and 5- flurouracil (TPF) followed by CRT utilizing weekly cisplatin and had pretreatment 18F-FDG-PET. We examined the association between the pretreatment primary tumor maximum standardized uptake value (SUVmax) and the treatment outcomes. The disease-free survival (DFS), and overall survival (OS) were calculated by the Kaplan-Meier method, and the differences were evaluated on logrank test. The prognostic significance was assessed by univariate and multivariate analyses. Results: The study included 38 eligible LANC patients. The 4-year OS and PFS rates were 94.9% and 84.7%, respectively. The median OS and PFS intervals were not reached. On univariate analysis, the 4-years DFS was significantly higher in patients with pretreatment SUVmax 8 compared to > 8 (92.3% vs 56%, P = 0.017). It was also significantly correlated to pretreatment T stage (P=0.001), N stage (P=0.011) and the treatment response (P < 0.001) and treatment breaks (P< 0.001). On a multivariate analysis, the SUVmax category was the only factor correlated with 4-year DFS (hazard ratio = 13.2, 95% C I 1.27-136.8, P= 0. 030) but not for OS (P = 0.068). Conclusions: This study shows that the pretreatment primary tumor SUVmax is a potential independent prognostic predictor of clinical outcomes in patients with LANC treated definitively with TPF induction chemotherapy followed by CRT. Further randomized controlled clinical III trials are needed to provide clear evidence of this benefit.