Predictive value of ¹⁸F-Fluorodeoxyglucose uptake by positronemission tomography for non-small cell lung cancerpatients treated with radical radiotherapy

The purpose of this study is to assess predictive value of the positron emission tomography (PET) with 18F-fluoro-deoxyglucose (FDG) for recurrence and survival after radiotherapy (RT) for non-small cell lung cancer (NSCLC). One hundred forty-nine patients underwent pretreatment PET (n = 67) or PET/computed tomography (CT) (n = 82) and definitive RT for NSCLC. We evaluated the relationship between the maximum-pixel standardized uptake value (SUV_max) and clinical tumor features. Univariate Cox proportional hazard analysis (UVA) was used to quantify the risk for local-regional recurrence, distant metastases, and death. Multivariate Cox proportional hazard analysis (MVA) was used to assess the potential independent effect of SUV_max. In the PET group, T1 tumors showed significantly lower SUV_max than T2, T3, and T4 tumors; in the PET/CT group, T1 tumors showed significantly lower SUV_max than T3 and T4 tumors. A high SUV_max was a negative factor for local-regional control (LRC) (p < 0.001), distant metastasis-free survival (DMFS) (p = 0.02), and overall survival (OS) (p = 0.001) on UVA in the PET group. However, the significance decreased to 0.05 for LRC, 0.04 for DMFS, and 0.04 for OS by MVA when tumor size was included in the analysis. A high SUV_max was not a negative factor for LRC, DMFS, or OS on UVA and MVA in the PET/CT group. In conclusion, assessment of predictive value of SUV_maxfor NSCLC requires consideration of primary tumor size, and the evidence is not sufficient to suggest that FDG uptake in a primary NSCLC provides prognostic information.