Pretreatment maximum standardized uptake value on 18F-fluorodeoxyglucose positron emission tomography is a predictor of outcome for stage I non-small cell lung cancer after stereotactic body radiotherapy

Aims: Stereotactic body radiotherapy (SBRT) is commonly considered an important treatment option for patients with stage I non-small cell lung cancer (NSCLC) who have contraindications for surgery or refuse surgery. Many studies have reported that the maximum standardized uptake value (SUVmax) on 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) of the primary tumor has prognostic value for resected NSCLC. The purpose of this study was to determine whether SUVmax is a predictor of disease-free survival (DFS) in patients with stage I NSCLC after SBRT. Methods: In all patients, the diagnosis was pathologically or cytologically confirmed. The prescription dose was 48Gy in four fractions at the isocenter. FDG-PET was performed before SBRT. Results: Twenty-nine patients were enrolled in this study. The median follow-up period was 14 months (range, 2-56 months). Regional lymph node metastasis and distant metastasis were observed in 5 (17%) and 2 (7%), respectively. The median SUVmax was 5.6 (range, 2.2-22.0). DFS at 2 years was significantly different between the low SUVmax (<8.0) and high SUVmax (≥8.0) groups (85 versus 17%). In univariate analysis, SUVmax and gross tumor volume were significantly correlated with DFS. Multivariate analysis included variables with P-values <0.20 and showed that only SUVmax was significantly correlated with DFS. Conclusion: Pretreatment SUVmax on FDG-PET predicted the DFS in patients with stage I NSCLC after SBRT.