Background: In 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.
Methods: Prospectively, 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.
Results: In 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.
Conclusions: This 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.
Keywords: 18F-FDG PET/CT; SUV; circulating tumor cells (CTCs); non-small cell lung cancer (NSCLC); total lesion glycolysis (TLG).
2020 Translational Lung Cancer Research. All rights reserved.