18F-FDG PET/CT total lesion glycolysis is associated with circulating tumor cell counts in patients with stage I to IIIA non-small cell lung cancer

Abstract

BackgroundIn non-small cell lung cancer (NSCLC), 18F-fluoro-2-deoxy-D-glucose (18F-FDG) uptake determined by PET and presence of circulating tumor cells (CTCs) in the peripheral blood independently predict outcomes. For 18F-FDG PET/CT staging interpretation, standardized uptake values (SUVmax/avg) are routinely used in clinical reporting. The goal was to investigate whether 18F-FDG uptake measured by SUVmax/avg, but also measures of metabolic tumor volume (MTV) and total lesion glycolysis (TLG) (MTV × SUVavg), are associated with CTCs.MethodsProspectively, 7.5 mL blood was drawn from NSCLC patients at the time of staging 18F-FDG PET/CT and from healthy control subjects. CTCs were identified by immunofluorescent staining (CK8/18/19pos/EpCAMpos/CD45neg/DAPIpos nucleus). 18F-FDG PET/CTs were analyzed for SUVmax, SUVavg, MTV, and TLG.ResultsIn 16 NSCLC patients with stage I–IIIA, MTV and TLG, in contrast to SUVmax and SUVavg, were positively associated with CTCs (linear regression analysis). No CTCs were detectable in 20 healthy control subjects.ConclusionsThis pilot study demonstrates that 18F-FDG PET/CT TLG correlates with CTCs in NSCLC patients without distant metastases. TLG might be a more appropriate marker for hematogenous micrometastatic potential than SUVs.