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 48 Gy 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 .