Prognositc significance of SUV_max on pretreatment ¹⁸ F-FDG PET/CT in early-stage non-small cell lung cancer treated with stereotactic body radiotherapy: A meta-analysis

Introduction: The prognostic importance of the ¹⁸ F-FDG PET maximum standardized uptake value (SUV_max ) for early stage non-small cell lung cancer (NSCLC) patients receiving stereotactic body radiotherapy (SBRT) is not well defined. The purpose of this meta-analysis is to evaluate the efficacy of SUV_max on pretreatment ¹⁸ F-FDG PET imaging to predict prognosis after SBRT.

Methods: All published English-language studies that assessed the treatment response after SBRT in patients with early-stage NSCLC using ¹⁸ F-FDG PET were collected from the EMBASE and MEDLINE databases. All the included studies were published between January 2000 and June 2015 and limited to NSCLC, PET/CT, SBRT, and the impact of SUV_max on survival. The necessary data for the calculation of individual hazard ratios (HRs) were extracted from each publication. All the results were independently verified and examined by two reviewers to ensure accuracy.

Results: After evaluating the original articles, 11 retrospective studies (1008 patients) were included into the meta-analysis. Data were available in 11 studies for pre-SBRT primary tumour SUV_max . Seven studies (798 patients) were included for the overall survival (OS) analysis with a combined HR of 1.10 (95% CI, 1.05-1.15). Five studies (487 patients) were included for the local control analysis with a combined HR of 1.13 (95% CI, 1.06-1.21). Three studies (365 patients) were analysed for distant metastasis with a combined HR of 1.09 (95% CI, 1.03-1.16).

Conclusion: Patients with high levels of pre-SBRT SUV_max had poorer overall survival and local control and higher distant metastases. Further prospective studies are warranted to confirm the prognostic value of FDG uptake in early-stage NSCLC patients receiving SBRT.