Maximum Standardized Uptake Value on FDG-PET Is a Strong Predictor of Overall and Disease-Free Survival for Non–Small-Cell Lung Cancer Patients after Stereotactic Body Radiotherapy

Introduction:The maximum standardized uptake value (SUVmax) on 18F-fluorodeoxyglucose positron emission tomography is a predictor for overall survival (OS) in non–small-cell lung cancer (NSCLC) after resection. We investigated the association between SUVmax and outcomes in NSCLC after stereotactic body radiotherapy.Methods:Between 2005 and 2012, 283 patients with early NSCLC (T1a-2N0M0) were treated with stereotactic body radiotherapy; the total doses were 40 to 60 Gy in five fractions. Patients who underwent staging 18F-fluorodeoxyglucose positron emission tomography scans by a single scanner and were followed up for more than or who died within 6 months were eligible. The optimal threshold SUVmax was calculated for each outcome. Outcomes were analyzed using the Kaplan–Meier method and log-rank test. Prognostic significance was assessed by univariate and multivariate analyses.Results:One hundred fifty-two patients were eligible. Median follow-up was 25.3 (range, 1.3–77.4) months. Local, regional, and distant recurrences, cancer-specific deaths, and deaths from other reasons occurred in 14, 11, 27, 21, and 31 patients, respectively. The optimal threshold SUVmax for local, regional, and distant recurrences, and disease-free survival (DFS), cancer-specific survival, and OS were 2.47 to 3.64. Outcomes of patients with SUVmax lower than each threshold were significantly better than those with higher SUVmax (all p<0.005): 3-year DFS rates were 93.0% versus 58.3% (p<0.001) and 3-year OS rates were 86.5% versus 42.2% (p<0.001), respectively. By multivariate analysis, higher SUVmax was a significantly worse predictor for DFS (p<0.01) and OS (p=0.04).Conclusions:SUVmax was a predictor for DFS and OS. A high SUVmax may be considered for intensive treatment to improve outcomes.