The maximum standardized uptake value (SUVmax) on FDG-PET is a strong predictor of local recurrence for localized non-small-cell lung cancer after stereotactic body radiotherapy (SBRT)

Background: The maximum standardized uptake value (SUVmax) of FDG-PET may predict local recurrence for localized non-small-cell lung cancer (NSCLC) after stereotactic body radiotherapy (SBRT). Methods: Among 195 localized NSCLCs that were treated with total doses of either 40 Gy or 50 Gy in 5 SBRT fractions, we reviewed those patients who underwent pre-treatment FDG-PET using a single scanner for staging. Local control rates (LCRs) were obtained by the Kaplan-Meier method and a log-rank test. Prognostic significance was assessed by univariate and multivariate analyses. Results: A total of 95 patients with 97 lesions were eligible. Median follow-up was 16.0 months (range: 6.0-46.3 months). Local recurrences occurred in 9 lesions. By multivariate analysis, only the SUVmax of a primary tumor was a significant predictor (p = 0.002). Two years LCRs for lower SUVmax (<6.0; n = 78) and higher SUVmax (≥6; n = 19) were 93% and 42%, respectively. In subgroups with T1b and T2, LCRs were significantly better for lower SUVmax than for higher SUVmax (p < 0.0005 and p < 0.01). In both subgroups that received 40 Gy and 50 Gy, LCRs were also significantly better for lower SUVmax than for higher SUVmax (p < 0.001 and p < 0.01). Conclusions: SUVmax was the strongest predictor for local recurrence. A high SUVmax may be considered for dose escalation to improve local control. Additional follow-up is needed to determine if SUVmax is correlated with regional recurrence, distant metastasis, and survival.